View allAll Photos Tagged Testbed
+++ DISCLAIMER +++
Nothing you see here is real, even though the model, the conversion or the presented background story might be based historical facts. BEWARE!
Some background:
In the aftermath of the Second World War, Sweden required a strong air defense, utilizing the newly developed jet propulsion technology. The original concept had been designed around a mostly straight wing, but after Swedish engineers had obtained German research data on swept-wing designs, the prototype was altered to incorporate a 25° sweep. In order to make the wing as thin as possible, Saab elected to locate the retractable undercarriage in the aircraft's fuselage rather than into the wings.
Extensive wind tunnel testing had also influenced aspects of the aircraft's aerodynamics, such as stability and trim across the aircraft's speed range. In order to test the design of the swept wing further and avoid any surprises, it was decided to modify a Saab Safir. It received the designation Saab 201 and a full-scale swept wing for a series of flight tests. The first 'final' sketches of the aircraft, incorporating the new information, were drawn in January 1946.
The originally envisioned powerplant for the new fighter type was the de Havilland Goblin turbojet engine. However, in December 1945, information on the newer and more powerful de Havilland Ghost engine became available. The new engine was deemed to be ideal for Saab's in-development aircraft, as not only did the Ghost engine had provisions for the use of a central circular air intake, the overall diameter of the engine was favorable for the planned fuselage dimensions, too. Thus, following negotiations between de Havilland and Saab, the Ghost engine was selected to power the type and built in license as the RM 2.
By February 1946 the main outline of the proposed aircraft had been clearly defined. In autumn 1946, following the resolution of all major questions of principal and the completion of the project specification, the Swedish Air Force formally ordered the completion of the design and that three prototype aircraft be produced, giving the proposed type the designation J 29. After a thorough test program, production of the type commenced in 1948 and, in May 1951, the first deliveries of operational production aircraft were received by F 13 Norrköping. The J 29 proved to be very successful and several variants and updates of the Tunnan were produced, including a dedicated reconnaissance variant, a two seat trainer and an all-weather fighter with an onboard radar
However, Sweden foresaw that there would soon be a need for a jet fighter that could intercept bombers at high altitude and also successfully engage fighters. During September 1949, the Swedish Air Force, via the Swedish Defence Material Administration, released a requirement for a cutting-edge interceptor aircraft that was envisioned to be capable of attacking hostile bomber aircraft in the transonic speed range. As released, this requirement specified a top speed of Mach speed 1.4 to 1.5. (1956, the specified speed was revised and raised to Mach 1.7-1.8, and eventually led to the Saab 35 Draken). With the barely supersonic Saab 32 Lansen just under development, and intended for different roles than being a nimble day fighter, the company searched for a way to either achieve supersonic flight through modifications of an existing type or at least gather sufficient data and develop and try the new technologies necessary to meet the 1949 requirements.
Since Sweden did not have a truly supersonic aircraft in its inventory (not even an experimental type), Saab decided to convert the Saab 29 into a supersonic testbed, with the outlook to develop an interim day fighter that could replace the various Tunnan fighter versions and support the new Lansen fleet until a fully capable Mach 1.5+ interceptor was ready for service. Even though the type was regarded as a pure experimental aircraft, the designation remained close to the J29 nomenclature in order to secure military funding for the project and to confuse eventual spies. Consequently, the P29 was initially presented as a new J29 version (hence the “G” suffix).
The P29G was based on a heavily modified production J29B airframe, which was built in two versions and only in two specimens. Work on the first airframe started in 1952, just when the first Saab 32 prototype made its maiden flight. The initial challenge consisted of integrating two relatively compact axial flow jet engines with afterburners into the fuselage, since the J29’s original RM2, even in its late afterburner variant, was not able to safely deliver the necessary thrust for the intended supersonic flight program. After long negotiations, Saab was able to procure a small number of Westinghouse J34-WE-42 turbojets from the USA, which delivered as a pair 40% more thrust than the original RM2B. The engines were only delivered under the restriction that they would exclusively be used in connection with the supersonic research program.
Through a thorough re-construction, the Saab team was able to mount the new engines into the lower rear fuselage, and, internally, the air intake duct had to be modified and forked behind the landing gear wells. Due to the significantly widened rear fuselage, the P29G became quickly nicknamed “Kurviga Tunnan” (= “Curvy Barrel”). Even though the widened rear fuselage increased the aircraft’s frontal cross section, the modified shape had the (unintended) effect of area ruling, a welcome side benefit which became apparent during the flight test and which largely promoted the P29G’s gain of top speed.
Another special and unique feature of the P29G was a special wing attachment system. It consisted of two strengthened, open box spars in the fuselage with additional attachment points along the wing roots, which allowed different wings to be switched with relatively little effort. However, due to this modification, the wing tanks (with a total capacity of 900l inside of the J29s standard wings) were lost and only 2.150l in the Saab 29’s standard fuselage tanks could be carried – but this was, for a research aircraft, not regarded as a major weakness, and compensated for the wing attachment system’s additional weight. The original wing-mounted pitots were replaced by a single, massive sensor boom attached to the aircraft’s nose above the air intake, slightly set-off to starboard in order to give the pilot an unobstructed view.
The first P29G's maiden flight, marked “Gul Urban” (Yellow U), took place in July 1955. The aircraft behaved normally, even though the center of gravity had markedly shifted backwards and the overall gain of weight made the aircraft slightly unstable along the longitudinal axis. During the initial, careful attempts to break the sound barrier, it soon became apparent that both the original wings as well as the original air intake shape limited the P29G's potential. In its original form, the P29G could only barely pass Mach 1 in level flight.
As a consequence, the second P29G, which had been under conversion from another J29B airframe since mid-1954, received more thorough modifications. The air intake was lengthened and widened, and in order to make it more effective at supersonic speed it received a sharp lip. Wind tunnel tests with the first machine led to a modified tail, too: the fin was now taller and further swept back, the stabilizer was moved to a higher position, resulting in a cruciform layout. The original single-piece stabilizer was furthermore replaced by a two-piece, all-moving construction with a 45° sweep and a thinner profile. This not only improved the aerodynamics at high speed, it also suppressed the longitudinal instability problem, even though this was never really cured.
Due to the even higher all-up weight of the new aircraft, the landing gear was reinforced and the 2nd P29G received an experimental suspension system on its main legs with higher spring travel, which was designed for operations on semi-prepared airfields. This system had actually been designed for the updated J29 fighters (esp. the A32B attack variant), but it was not introduced into series production or the Saab 29E/F conversion program. Despite these massive changes, the P29G designation was retained, and the second machine, carrying the tactical code “Röd Urban” (Red U), was quickly nicknamed “Karpen” (“Carp”), due to its characteristic new intake shape, the long fin and its stocky shape.
The second P29G was ready for flight tests in August 1956, just in time to support the Saab 35’s ongoing development – the aircraft, which was eventually built to meet (and exceed) the Swedish Air Force’s 1949 supersonic interceptor requirement. The modifications proved to be successful and the P29G was, fitted with a 60° sweep wing and in clean configuration, able to achieve a maximum speed of 1.367 km/h (849 mph) in level flight, a formidable achievement (vs. the 1,060 km/h (660 mph) of the late J29F and the 1200 km/h (745 mph) of the J32B interceptor) for the post WWII design.
Several wing shapes and profiles were tested, including sweep angles from 25° to 63° as well as different shapes and profiles. Even though the machines carried provisions for the J29’s standard armament, the 20 mm cannons were normally not mounted and replaced with sensors and recording equipment. However, both machines were temporarily fitted with one or two guns in order to analyze the effects of firing the weapons at supersonic speed. Underwing ordnance was also almost never carried. In some tests, though, light bombs or unguided missiles were carried and deployed, or podded cine cameras were carried.
While the second P29G was used for high speed trials, the first machine remained in its original guise and took over low speed handling tests. Thanks to the unique wing switch mechanism, the supersonic research program could be held within a very tight schedule and lasted until late 1959. Thereafter, the P29Gs’ potential was of little use anymore, and the engine use agreement with the USA put an end to further use of the two aircraft, so that both P29Gs were retired from service in 1960. The 1st machine, outfitted with standard J29F wings and stripped off of its engines, remained in use as an instructional air at Malmslätt air base 1969, while the second machine was mothballed. However, both airframes were eventually scrapped in 1970.
General characteristics:
Crew: 1
Length: 11.66 m (38 ft 2 in) fuselage only,
13,97 m (45 ft 9 in) with pitot boom
Wingspan: varied*; 11.0 m (36 ft 1 in) with standard 25° sweep wings,
10.00 m (32 ft 9 ¾ in) with experimental 45° wings
Height: 4.54m (14 ft 10 ½ in)
Wing area: varied*; 24.15 m² (260.0 ft²) with standard 25° sweep wings
22.5 m² (242.2 ft²) with experimental 45° wings
Empty weight: 5,220 kg (11,500 lb)
Max. takeoff weight: 8,510 kg (18,744 lb)
Powerplant:
2× Westinghouse J34-WE-42 turbojets, each rated at 3,400 lbf (15 kN) dry thrust
and 4,200 lbf (19 kN) with full afterburner
Performance:
Maximum speed: 1.367 km/h (849 mph) were achieved*
Range: 790 km (490 mi)
Service ceiling: up to 17,250 m (56,500 ft)*
Rate of climb: up to 45 m/s (8,850 ft/min)*
*Varying figures due to different tested wing configurations
Armament:
None installed; provisions for 4x 20mm Hispano Mark V autocannon in the lower front fuselage.
Depending on the mounted wing type, various external loads could be carried, including a wide range of light bombs, 75 mm (3 in) air-to-air rockets, 145 mm (5.8 in) anti-armor rockets, 150 mm (6 in) HE (high-explosive) rockets or 180 mm (7.2 in) HE anti-ship rockets. Due to the lack of complex wiring or fuel plumbing, no guided weapons or drop tanks could be mounted, though.
The kit and its assembly:
Sweden is a prolific whiffing territory, and the Saab 29 offers some interesting options. This highly modified Tunnan, which is actually rather a kitbashing than a mere model kit modification, is/was a submission to the “More or less engines” group build at whatifmodelers.com in summer 2019.
I actually had the idea of a two-engine J29 in the back of my mind for a long time, spawned by a resin conversion set for the Hasegawa B-47 Stratojet kit that came with new intakes and exhaust sections for the four engine pods. The single engine pod parts had been spent a long time ago, but the twin engine parts were still waiting for a good use. Could the exhaust fit under/into a Tunnan…?
I even had a Matchbox J29 stashed away for this experiment long ago, as well as some donor parts like the wings, and the GB eventually offered the right motivation to put those things together that no one would expect to work.
So I pulled out all the stuff and started – a rather straightforward affair. Work started with the fuselage, which was, together with the (very nice) cockpit assembled OOB at first, the nose filled with as much lead as possible and with the lower rear section cut away, so the B-47 resin jet nozzles would end up at the same position as the original RM2B exhaust. Due to the pen nib fairing between them, though, the profile of the modified tail became (visually) more massive, and I had to fill some gaps under the tail boom (with styrene sheet and putty). The twin engines also turned out to be wider than expected – I had hoped for straight flanks, but the fuselage shape ended up with considerable bulges behind the landing gear wells. These were created with parts from drop tank halves and blended into the rest of the lower hill with PSR work. In the same wake the area under the fin was sculpted and re-created, too.
At that point it became clear that I had to do more on the fuselage, esp. the front end, in order to keep the aircraft visually balance. A convenient solution became an F-100 air intake, which I grafted onto the nose instead of the original circular and round-lipped orifice – with its sharp lip the Super Sabre piece was even a plausible change! The fuselage shapes and diameters differed considerably, though, more PSR became necessary.
Next came the wings: I had already set apart a pair of trapezoid wings with a 45° sweep angle – these were left over from a PM Model Ta 183 conversion some time ago. With their odd shape and size they were a perfect match for my project, even more so due to the fact that I could keep the original J29 wing attachment points, I just had to shorten and modify the trailing edge area on the fuselage. The result was very conclusive.
With the new nose and the wings in place, the overall proportions became clearer: still tail-heavy, but not unpleasant. At this time I was also certain that I had to modify the tail surfaces. The fin was too small and did not have enough sweep for the overall look, and the stabilizer, with its thick profile, rounded edges and the single, continuous rudder did not look supersonic at all. What followed was a long search in the donor banks for suitable replacements, and I eventually came up with a MiG-15 fin (Hobby Boss) which was later clipped at the top for a less recognizable profile. The stabilizers were more challenging, though. My solution eventually became a pair of modified stabilizers from a Matchbox Buccaneer(!), attached to the MiG-15 fin.
The design problems did not stop here, though: the landing gear caused some more headaches. I wanted to keep the OOB parts, but especially the main legs would leave the aircraft with a very goofy look through a short wheelbase and a rear axis position too much forward. In an attempt to save the situation I attached swing arms to the OOB struts, moving the axis maybe 5mm backwards and widening the track by 2mm at the same time. Not much in total, but it helped (a little, even though the aircraft is still very tail-heavy)
As a final addition – since the original, wing-mounted pitots of the J29 were gone now and would not go well with the wing-switching idea – I gave the P29G a large, nose-mounted pitot and sensor boom, placed on top of the nose. This part come, like the air intake, from an F-100.
Painting and markings:
I tend to be conservative when it comes to liveries for what-if models, and the P29G is no exception. At first, I thought that this build could become an operational supersonic daylight interceptor (the J29G), so that I could give the model full military markings and maybe a camouflage paint scheme. However, this idea would not work: the potential real life window for such an aircraft, based on the Saab 29, would be very narrow. And aircraft development in the late Fifties made quantum leaps within a very short period of time: While the J29A entered service, work on the Mach 2 Saab 35 was already underway – nobody would have accepted (or needed) a Mach 1 fighter, based on late Forties technology, at that time anymore, and there was the all-weather Saab J32B around, too. The update program with new wings and a more powerful afterburner engine was all that could be done to exploit the Tunnan’s potential, resulting in the (real world’s) J29E and F variants.
I eventually decided that the J29G would only be a prototype/research aircraft, consequently called P29G, and through this decision I became more or less settled upon a NMF finish with some colorful markings. Consequently, the model was painted with various shades of metal colors, primarily Polished Aluminum Metallizer from Humbrol, but also with Humbrol 191 and Matt Aluminum Metallizer as well as ModelMaster Steel Metallizer. Around the exhaust section, I also used Revell 91 (Iron) and ModelMaster Exhaust Metallizer. Some single panels and details were painted with Revell 99 (Aluminum), and I also used generic decal material in silver to simulate some smaller access panels. Grey decal sheet was used to simulate covers for the cannon nozzles.
The cockpit interior was painted, according to Saab 29 standard, in a dark greenish-grey (Revell 67), and bluish grey was used inside of the landing gear wells (Revell 57). The pitot boom received black and white stripes.
For markings I let myself get inspired from the real world Saab 29 and 32 prototypes, which were all marked with a colored “U” tactical code on the fin and also on the front fuselage, simply meaning “Utverding” (= “Test”). I found four red decals, and I also gave the aircraft a yellow cheatline, lent from an Airfix F-86D decal sheet. The Swedish roundels come from a generic aftermarket sheet, most stencils were taken from the Revell OOB sheet and a Printscale J29 sheet.
Before the model was sealed with semi-gloss acrylic varnish from Italeri, some grinded graphite was rubbed onto the rear fuselage, adding a metallic shine and simulating exhaust stains.
A thorough conversion – this has rather evolved into a kitbashing than just a kit conversion: not much from the original Matchbox J29 has been left over. But I like the outcome, even though things developed gradually from the simple idea of changing the number of engines on the Tunnan. One thing led to another. The resulting aircraft looks quite plausible, even though I am not totally happy with the landing gear, which appears to be rather far forward, despite surgical measures to mend the situation. The Ta 183 wings are a very good match, though, and I cannot help but recognize a certain French look, maybe due to the cruciform tail and the oval air intake? The P29G could also, with Argentinian marking, have become a revised version of the FMA Pulqui II?
Once the fastest production car in the world, the Jaguar XK120 was Jaguar's first new product following the end of the war, being designed in those dark final days of the conflict and being developed over the next three years, making its début in 1948.
The XK120 was launched in open two-seater form at the 1948 London Motor Show as a testbed and show car for the new Jaguar XK engine. The display car was the first prototype, chassis number 670001. It looked almost identical to the production cars except that the straight outer pillars of its windscreen would be curved on the production version. The roadster caused a sensation, which persuaded Jaguar founder and design boss William Lyons to put it into production.
Beginning in 1948, the first 242 cars wore wood-framed open 2-seater bodies with aluminium panels. Production switched to the 112lb heavier all-steel in early 1950. The "120" in the name referred to the aluminium car's 120 mph top speed, which made it the world's fastest production car at the time of its launch. Engine models ranged from a 160bhp DOHC Straight-6 Double SU H6 low end model, to the fastest version which was powered by a 210bhp DOHC Straight-6 Double SU H8, giving the car a top speed of 124mph, which in 1949 was a spectacular feat when compared to the Austins and Morris' of the time.
On 30 May 1949, on the empty Ostend-Jabbeke motorway in Belgium, a prototype XK120 timed by the officials of the Royal Automobile Club of Belgium achieved an average of runs in opposing directions of 132.6 mph with the windscreen replaced by just one small aeroscreen and a catalogued alternative top gear ratio, and 135 mph with a passenger-side tonneau cover in place. In 1950 and 1951, at a banked oval track in France, XK120 roadsters averaged over 100 mph for 24 hours and over 130 mph for an hour, and in 1952 a fixed-head coupé took numerous world records for speed and distance when it averaged 100 mph for a week.
The Motor magazine road-tested an XK120 roadster in November 1949. This pre-production car, chassis number 670001, road-registered as HKV 455, was the first prototype built. It was also the 1948 London Motor Show display model, and had been driven by Prince Bira in the 1949 Silverstone Production Car Race. The magazine reported a top speed of 124.6 mph, acceleration from 0–60 mph in 10.0 seconds and fuel consumption of 19.8 miles per imperial gallon. The car as tested cost £1263 including taxes.
In 1949 the first production roadster, chassis number 670003, was delivered to famous actor Clark Gable.
The XK120 was ultimately available in two open versions, first as an open 2-seater described in the US market as the roadster, then also as a drophead coupé from 1953; and also as a closed, or fixed head coupé from 1951.
Production of the car ended in 1954 after 12,055 examples were constructed, being replaced by the Jaguar XK140. Today you'd be hard pressed to find XK120's on a regular basis, but if you attend car shows like me you'd be likely to find at least one show up.
Most notably though, the car returned to the centre stage of modern motoring through a spectacularly organised and choreographed race between the presenters of Top Gear on their Race to the North, a competition set in a hypothetical 1949 between the primary modes of transport at the time, with James May in the Jaguar XK120, Richard Hammond on a Vincent Blackshadow motorbike, and Jeremy Clarkson on the rebuilt Peppercorn A1 Pacific number 60163 'Tornado'.
Airbus A380-861
MSN 004 [Engine Alliance testbed]
F-WWDD 'VNO' ['#A380' 'iflyA380.com' decals]
Airbus S.A.S.
Copyright © 2016 A380spotter. All rights reserved.
Operator: Airbus Industrie
Aircraft: Airbus A321-251neo
Registration: D-AVXB
C/n: 6839
Time & Location: 01.10.2016, EFTU, Finland
Remarks: the 2nd A321neo built.
KLAX (Los Angeles International Airport) - 12 AUG 2020
"Cargolux Three Seven Bravo Heavy" from Glasgow Prestwick Airport (PIK/EGPK) on short final to RWY 25L.
Production Site: Everett (PAE)
Rollout: 12 NOV 2009
First Flight: 08 FEB 2010
Test Registrations: N747EX, N5020K
To Boeing: 12 NOV 2009 as N747EX
Aircraft Name: Jack Waddell
Hex Code: AA0D05
Configuration: Testbed
Engines: 4x General Electric GEnx-2B67
Re-registered to Boeing: SEP 2012 as N5020K
Hex Code: A643C0
Configuration: Testbed
Engines: 4x General Electric GEnx-2B67
Delivery to Cargolux Airlines International: 08 MAR 2013 as LX-VCA
Ferried PAE-SEA-LAX-LUX on 08-09 MAR 2013 on delivery
Aircraft Name: City of Vianden
Hex Code: 4D0103
Configuration: Cargo
Engines: 4x General Electric GEnx-2B67
Airfix Lancaster converted to a Lincoln and modified to represent Armstrong-Siddeley Python testbed RF403
Bright, neatly organized network cables connect the servers in the DETER testbed at the USC Information Sciences Insititue (ISI), in Marina Del Rey, CA.
Airbus A350F first flight - 29/09/2026
First A350F followed by the Falcon 20 for exterior inspection during test flight.
Airbus A350-1041F. Airbus Industries. F-WXLD. MSN: 700
In 1972 Volvo Presented its rolling safety laboratory, the VESC. It was meant to work as both an experimental vehicle and as a testbed for future safety features, such as anti-lock brakes, airbags and telescopic action bumpers. The front end of the car remained almost unchanged into the 240/260 models of 1974. Technical features based on the 140 series.
Volvo Museum
Arendals Skans
405 08 Göteborg
Sweden
July 2012
+++ DISCLAIMER +++
Nothing you see here is real, even though the model, the conversion or the presented background story might be based historical facts. BEWARE!
Some background:
In the aftermath of the Second World War, Sweden required a strong air defense, utilizing the newly developed jet propulsion technology. The original concept had been designed around a mostly straight wing, but after Swedish engineers had obtained German research data on swept-wing designs, the prototype was altered to incorporate a 25° sweep. In order to make the wing as thin as possible, Saab elected to locate the retractable undercarriage in the aircraft's fuselage rather than into the wings.
Extensive wind tunnel testing had also influenced aspects of the aircraft's aerodynamics, such as stability and trim across the aircraft's speed range. In order to test the design of the swept wing further and avoid any surprises, it was decided to modify a Saab Safir. It received the designation Saab 201 and a full-scale swept wing for a series of flight tests. The first 'final' sketches of the aircraft, incorporating the new information, were drawn in January 1946.
The originally envisioned powerplant for the new fighter type was the de Havilland Goblin turbojet engine. However, in December 1945, information on the newer and more powerful de Havilland Ghost engine became available. The new engine was deemed to be ideal for Saab's in-development aircraft, as not only did the Ghost engine had provisions for the use of a central circular air intake, the overall diameter of the engine was favorable for the planned fuselage dimensions, too. Thus, following negotiations between de Havilland and Saab, the Ghost engine was selected to power the type and built in license as the RM 2.
By February 1946 the main outline of the proposed aircraft had been clearly defined. In autumn 1946, following the resolution of all major questions of principal and the completion of the project specification, the Swedish Air Force formally ordered the completion of the design and that three prototype aircraft be produced, giving the proposed type the designation J 29. After a thorough test program, production of the type commenced in 1948 and, in May 1951, the first deliveries of operational production aircraft were received by F 13 Norrköping. The J 29 proved to be very successful and several variants and updates of the Tunnan were produced, including a dedicated reconnaissance variant, a two seat trainer and an all-weather fighter with an onboard radar
However, Sweden foresaw that there would soon be a need for a jet fighter that could intercept bombers at high altitude and also successfully engage fighters. During September 1949, the Swedish Air Force, via the Swedish Defence Material Administration, released a requirement for a cutting-edge interceptor aircraft that was envisioned to be capable of attacking hostile bomber aircraft in the transonic speed range. As released, this requirement specified a top speed of Mach speed 1.4 to 1.5. (1956, the specified speed was revised and raised to Mach 1.7-1.8, and eventually led to the Saab 35 Draken). With the barely supersonic Saab 32 Lansen just under development, and intended for different roles than being a nimble day fighter, the company searched for a way to either achieve supersonic flight through modifications of an existing type or at least gather sufficient data and develop and try the new technologies necessary to meet the 1949 requirements.
Since Sweden did not have a truly supersonic aircraft in its inventory (not even an experimental type), Saab decided to convert the Saab 29 into a supersonic testbed, with the outlook to develop an interim day fighter that could replace the various Tunnan fighter versions and support the new Lansen fleet until a fully capable Mach 1.5+ interceptor was ready for service. Even though the type was regarded as a pure experimental aircraft, the designation remained close to the J29 nomenclature in order to secure military funding for the project and to confuse eventual spies. Consequently, the P29 was initially presented as a new J29 version (hence the “G” suffix).
The P29G was based on a heavily modified production J29B airframe, which was built in two versions and only in two specimens. Work on the first airframe started in 1952, just when the first Saab 32 prototype made its maiden flight. The initial challenge consisted of integrating two relatively compact axial flow jet engines with afterburners into the fuselage, since the J29’s original RM2, even in its late afterburner variant, was not able to safely deliver the necessary thrust for the intended supersonic flight program. After long negotiations, Saab was able to procure a small number of Westinghouse J34-WE-42 turbojets from the USA, which delivered as a pair 40% more thrust than the original RM2B. The engines were only delivered under the restriction that they would exclusively be used in connection with the supersonic research program.
Through a thorough re-construction, the Saab team was able to mount the new engines into the lower rear fuselage, and, internally, the air intake duct had to be modified and forked behind the landing gear wells. Due to the significantly widened rear fuselage, the P29G became quickly nicknamed “Kurviga Tunnan” (= “Curvy Barrel”). Even though the widened rear fuselage increased the aircraft’s frontal cross section, the modified shape had the (unintended) effect of area ruling, a welcome side benefit which became apparent during the flight test and which largely promoted the P29G’s gain of top speed.
Another special and unique feature of the P29G was a special wing attachment system. It consisted of two strengthened, open box spars in the fuselage with additional attachment points along the wing roots, which allowed different wings to be switched with relatively little effort. However, due to this modification, the wing tanks (with a total capacity of 900l inside of the J29s standard wings) were lost and only 2.150l in the Saab 29’s standard fuselage tanks could be carried – but this was, for a research aircraft, not regarded as a major weakness, and compensated for the wing attachment system’s additional weight. The original wing-mounted pitots were replaced by a single, massive sensor boom attached to the aircraft’s nose above the air intake, slightly set-off to starboard in order to give the pilot an unobstructed view.
The first P29G's maiden flight, marked “Gul Urban” (Yellow U), took place in July 1955. The aircraft behaved normally, even though the center of gravity had markedly shifted backwards and the overall gain of weight made the aircraft slightly unstable along the longitudinal axis. During the initial, careful attempts to break the sound barrier, it soon became apparent that both the original wings as well as the original air intake shape limited the P29G's potential. In its original form, the P29G could only barely pass Mach 1 in level flight.
As a consequence, the second P29G, which had been under conversion from another J29B airframe since mid-1954, received more thorough modifications. The air intake was lengthened and widened, and in order to make it more effective at supersonic speed it received a sharp lip. Wind tunnel tests with the first machine led to a modified tail, too: the fin was now taller and further swept back, the stabilizer was moved to a higher position, resulting in a cruciform layout. The original single-piece stabilizer was furthermore replaced by a two-piece, all-moving construction with a 45° sweep and a thinner profile. This not only improved the aerodynamics at high speed, it also suppressed the longitudinal instability problem, even though this was never really cured.
Due to the even higher all-up weight of the new aircraft, the landing gear was reinforced and the 2nd P29G received an experimental suspension system on its main legs with higher spring travel, which was designed for operations on semi-prepared airfields. This system had actually been designed for the updated J29 fighters (esp. the A32B attack variant), but it was not introduced into series production or the Saab 29E/F conversion program. Despite these massive changes, the P29G designation was retained, and the second machine, carrying the tactical code “Röd Urban” (Red U), was quickly nicknamed “Karpen” (“Carp”), due to its characteristic new intake shape, the long fin and its stocky shape.
The second P29G was ready for flight tests in August 1956, just in time to support the Saab 35’s ongoing development – the aircraft, which was eventually built to meet (and exceed) the Swedish Air Force’s 1949 supersonic interceptor requirement. The modifications proved to be successful and the P29G was, fitted with a 60° sweep wing and in clean configuration, able to achieve a maximum speed of 1.367 km/h (849 mph) in level flight, a formidable achievement (vs. the 1,060 km/h (660 mph) of the late J29F and the 1200 km/h (745 mph) of the J32B interceptor) for the post WWII design.
Several wing shapes and profiles were tested, including sweep angles from 25° to 63° as well as different shapes and profiles. Even though the machines carried provisions for the J29’s standard armament, the 20 mm cannons were normally not mounted and replaced with sensors and recording equipment. However, both machines were temporarily fitted with one or two guns in order to analyze the effects of firing the weapons at supersonic speed. Underwing ordnance was also almost never carried. In some tests, though, light bombs or unguided missiles were carried and deployed, or podded cine cameras were carried.
While the second P29G was used for high speed trials, the first machine remained in its original guise and took over low speed handling tests. Thanks to the unique wing switch mechanism, the supersonic research program could be held within a very tight schedule and lasted until late 1959. Thereafter, the P29Gs’ potential was of little use anymore, and the engine use agreement with the USA put an end to further use of the two aircraft, so that both P29Gs were retired from service in 1960. The 1st machine, outfitted with standard J29F wings and stripped off of its engines, remained in use as an instructional air at Malmslätt air base 1969, while the second machine was mothballed. However, both airframes were eventually scrapped in 1970.
General characteristics:
Crew: 1
Length: 11.66 m (38 ft 2 in) fuselage only,
13,97 m (45 ft 9 in) with pitot boom
Wingspan: varied*; 11.0 m (36 ft 1 in) with standard 25° sweep wings,
10.00 m (32 ft 9 ¾ in) with experimental 45° wings
Height: 4.54m (14 ft 10 ½ in)
Wing area: varied*; 24.15 m² (260.0 ft²) with standard 25° sweep wings
22.5 m² (242.2 ft²) with experimental 45° wings
Empty weight: 5,220 kg (11,500 lb)
Max. takeoff weight: 8,510 kg (18,744 lb)
Powerplant:
2× Westinghouse J34-WE-42 turbojets, each rated at 3,400 lbf (15 kN) dry thrust
and 4,200 lbf (19 kN) with full afterburner
Performance:
Maximum speed: 1.367 km/h (849 mph) were achieved*
Range: 790 km (490 mi)
Service ceiling: up to 17,250 m (56,500 ft)*
Rate of climb: up to 45 m/s (8,850 ft/min)*
*Varying figures due to different tested wing configurations
Armament:
None installed; provisions for 4x 20mm Hispano Mark V autocannon in the lower front fuselage.
Depending on the mounted wing type, various external loads could be carried, including a wide range of light bombs, 75 mm (3 in) air-to-air rockets, 145 mm (5.8 in) anti-armor rockets, 150 mm (6 in) HE (high-explosive) rockets or 180 mm (7.2 in) HE anti-ship rockets. Due to the lack of complex wiring or fuel plumbing, no guided weapons or drop tanks could be mounted, though.
The kit and its assembly:
Sweden is a prolific whiffing territory, and the Saab 29 offers some interesting options. This highly modified Tunnan, which is actually rather a kitbashing than a mere model kit modification, is/was a submission to the “More or less engines” group build at whatifmodelers.com in summer 2019.
I actually had the idea of a two-engine J29 in the back of my mind for a long time, spawned by a resin conversion set for the Hasegawa B-47 Stratojet kit that came with new intakes and exhaust sections for the four engine pods. The single engine pod parts had been spent a long time ago, but the twin engine parts were still waiting for a good use. Could the exhaust fit under/into a Tunnan…?
I even had a Matchbox J29 stashed away for this experiment long ago, as well as some donor parts like the wings, and the GB eventually offered the right motivation to put those things together that no one would expect to work.
So I pulled out all the stuff and started – a rather straightforward affair. Work started with the fuselage, which was, together with the (very nice) cockpit assembled OOB at first, the nose filled with as much lead as possible and with the lower rear section cut away, so the B-47 resin jet nozzles would end up at the same position as the original RM2B exhaust. Due to the pen nib fairing between them, though, the profile of the modified tail became (visually) more massive, and I had to fill some gaps under the tail boom (with styrene sheet and putty). The twin engines also turned out to be wider than expected – I had hoped for straight flanks, but the fuselage shape ended up with considerable bulges behind the landing gear wells. These were created with parts from drop tank halves and blended into the rest of the lower hill with PSR work. In the same wake the area under the fin was sculpted and re-created, too.
At that point it became clear that I had to do more on the fuselage, esp. the front end, in order to keep the aircraft visually balance. A convenient solution became an F-100 air intake, which I grafted onto the nose instead of the original circular and round-lipped orifice – with its sharp lip the Super Sabre piece was even a plausible change! The fuselage shapes and diameters differed considerably, though, more PSR became necessary.
Next came the wings: I had already set apart a pair of trapezoid wings with a 45° sweep angle – these were left over from a PM Model Ta 183 conversion some time ago. With their odd shape and size they were a perfect match for my project, even more so due to the fact that I could keep the original J29 wing attachment points, I just had to shorten and modify the trailing edge area on the fuselage. The result was very conclusive.
With the new nose and the wings in place, the overall proportions became clearer: still tail-heavy, but not unpleasant. At this time I was also certain that I had to modify the tail surfaces. The fin was too small and did not have enough sweep for the overall look, and the stabilizer, with its thick profile, rounded edges and the single, continuous rudder did not look supersonic at all. What followed was a long search in the donor banks for suitable replacements, and I eventually came up with a MiG-15 fin (Hobby Boss) which was later clipped at the top for a less recognizable profile. The stabilizers were more challenging, though. My solution eventually became a pair of modified stabilizers from a Matchbox Buccaneer(!), attached to the MiG-15 fin.
The design problems did not stop here, though: the landing gear caused some more headaches. I wanted to keep the OOB parts, but especially the main legs would leave the aircraft with a very goofy look through a short wheelbase and a rear axis position too much forward. In an attempt to save the situation I attached swing arms to the OOB struts, moving the axis maybe 5mm backwards and widening the track by 2mm at the same time. Not much in total, but it helped (a little, even though the aircraft is still very tail-heavy)
As a final addition – since the original, wing-mounted pitots of the J29 were gone now and would not go well with the wing-switching idea – I gave the P29G a large, nose-mounted pitot and sensor boom, placed on top of the nose. This part come, like the air intake, from an F-100.
Painting and markings:
I tend to be conservative when it comes to liveries for what-if models, and the P29G is no exception. At first, I thought that this build could become an operational supersonic daylight interceptor (the J29G), so that I could give the model full military markings and maybe a camouflage paint scheme. However, this idea would not work: the potential real life window for such an aircraft, based on the Saab 29, would be very narrow. And aircraft development in the late Fifties made quantum leaps within a very short period of time: While the J29A entered service, work on the Mach 2 Saab 35 was already underway – nobody would have accepted (or needed) a Mach 1 fighter, based on late Forties technology, at that time anymore, and there was the all-weather Saab J32B around, too. The update program with new wings and a more powerful afterburner engine was all that could be done to exploit the Tunnan’s potential, resulting in the (real world’s) J29E and F variants.
I eventually decided that the J29G would only be a prototype/research aircraft, consequently called P29G, and through this decision I became more or less settled upon a NMF finish with some colorful markings. Consequently, the model was painted with various shades of metal colors, primarily Polished Aluminum Metallizer from Humbrol, but also with Humbrol 191 and Matt Aluminum Metallizer as well as ModelMaster Steel Metallizer. Around the exhaust section, I also used Revell 91 (Iron) and ModelMaster Exhaust Metallizer. Some single panels and details were painted with Revell 99 (Aluminum), and I also used generic decal material in silver to simulate some smaller access panels. Grey decal sheet was used to simulate covers for the cannon nozzles.
The cockpit interior was painted, according to Saab 29 standard, in a dark greenish-grey (Revell 67), and bluish grey was used inside of the landing gear wells (Revell 57). The pitot boom received black and white stripes.
For markings I let myself get inspired from the real world Saab 29 and 32 prototypes, which were all marked with a colored “U” tactical code on the fin and also on the front fuselage, simply meaning “Utverding” (= “Test”). I found four red decals, and I also gave the aircraft a yellow cheatline, lent from an Airfix F-86D decal sheet. The Swedish roundels come from a generic aftermarket sheet, most stencils were taken from the Revell OOB sheet and a Printscale J29 sheet.
Before the model was sealed with semi-gloss acrylic varnish from Italeri, some grinded graphite was rubbed onto the rear fuselage, adding a metallic shine and simulating exhaust stains.
A thorough conversion – this has rather evolved into a kitbashing than just a kit conversion: not much from the original Matchbox J29 has been left over. But I like the outcome, even though things developed gradually from the simple idea of changing the number of engines on the Tunnan. One thing led to another. The resulting aircraft looks quite plausible, even though I am not totally happy with the landing gear, which appears to be rather far forward, despite surgical measures to mend the situation. The Ta 183 wings are a very good match, though, and I cannot help but recognize a certain French look, maybe due to the cruciform tail and the oval air intake? The P29G could also, with Argentinian marking, have become a revised version of the FMA Pulqui II?
+++ DISCLAIMER +++
Nothing you see here is real, even though the model, the conversion or the presented background story might be based historical facts. BEWARE!
Some background:
In the aftermath of the Second World War, Sweden required a strong air defense, utilizing the newly developed jet propulsion technology. The original concept had been designed around a mostly straight wing, but after Swedish engineers had obtained German research data on swept-wing designs, the prototype was altered to incorporate a 25° sweep. In order to make the wing as thin as possible, Saab elected to locate the retractable undercarriage in the aircraft's fuselage rather than into the wings.
Extensive wind tunnel testing had also influenced aspects of the aircraft's aerodynamics, such as stability and trim across the aircraft's speed range. In order to test the design of the swept wing further and avoid any surprises, it was decided to modify a Saab Safir. It received the designation Saab 201 and a full-scale swept wing for a series of flight tests. The first 'final' sketches of the aircraft, incorporating the new information, were drawn in January 1946.
The originally envisioned powerplant for the new fighter type was the de Havilland Goblin turbojet engine. However, in December 1945, information on the newer and more powerful de Havilland Ghost engine became available. The new engine was deemed to be ideal for Saab's in-development aircraft, as not only did the Ghost engine had provisions for the use of a central circular air intake, the overall diameter of the engine was favorable for the planned fuselage dimensions, too. Thus, following negotiations between de Havilland and Saab, the Ghost engine was selected to power the type and built in license as the RM 2.
By February 1946 the main outline of the proposed aircraft had been clearly defined. In autumn 1946, following the resolution of all major questions of principal and the completion of the project specification, the Swedish Air Force formally ordered the completion of the design and that three prototype aircraft be produced, giving the proposed type the designation J 29. After a thorough test program, production of the type commenced in 1948 and, in May 1951, the first deliveries of operational production aircraft were received by F 13 Norrköping. The J 29 proved to be very successful and several variants and updates of the Tunnan were produced, including a dedicated reconnaissance variant, a two seat trainer and an all-weather fighter with an onboard radar
However, Sweden foresaw that there would soon be a need for a jet fighter that could intercept bombers at high altitude and also successfully engage fighters. During September 1949, the Swedish Air Force, via the Swedish Defence Material Administration, released a requirement for a cutting-edge interceptor aircraft that was envisioned to be capable of attacking hostile bomber aircraft in the transonic speed range. As released, this requirement specified a top speed of Mach speed 1.4 to 1.5. (1956, the specified speed was revised and raised to Mach 1.7-1.8, and eventually led to the Saab 35 Draken). With the barely supersonic Saab 32 Lansen just under development, and intended for different roles than being a nimble day fighter, the company searched for a way to either achieve supersonic flight through modifications of an existing type or at least gather sufficient data and develop and try the new technologies necessary to meet the 1949 requirements.
Since Sweden did not have a truly supersonic aircraft in its inventory (not even an experimental type), Saab decided to convert the Saab 29 into a supersonic testbed, with the outlook to develop an interim day fighter that could replace the various Tunnan fighter versions and support the new Lansen fleet until a fully capable Mach 1.5+ interceptor was ready for service. Even though the type was regarded as a pure experimental aircraft, the designation remained close to the J29 nomenclature in order to secure military funding for the project and to confuse eventual spies. Consequently, the P29 was initially presented as a new J29 version (hence the “G” suffix).
The P29G was based on a heavily modified production J29B airframe, which was built in two versions and only in two specimens. Work on the first airframe started in 1952, just when the first Saab 32 prototype made its maiden flight. The initial challenge consisted of integrating two relatively compact axial flow jet engines with afterburners into the fuselage, since the J29’s original RM2, even in its late afterburner variant, was not able to safely deliver the necessary thrust for the intended supersonic flight program. After long negotiations, Saab was able to procure a small number of Westinghouse J34-WE-42 turbojets from the USA, which delivered as a pair 40% more thrust than the original RM2B. The engines were only delivered under the restriction that they would exclusively be used in connection with the supersonic research program.
Through a thorough re-construction, the Saab team was able to mount the new engines into the lower rear fuselage, and, internally, the air intake duct had to be modified and forked behind the landing gear wells. Due to the significantly widened rear fuselage, the P29G became quickly nicknamed “Kurviga Tunnan” (= “Curvy Barrel”). Even though the widened rear fuselage increased the aircraft’s frontal cross section, the modified shape had the (unintended) effect of area ruling, a welcome side benefit which became apparent during the flight test and which largely promoted the P29G’s gain of top speed.
Another special and unique feature of the P29G was a special wing attachment system. It consisted of two strengthened, open box spars in the fuselage with additional attachment points along the wing roots, which allowed different wings to be switched with relatively little effort. However, due to this modification, the wing tanks (with a total capacity of 900l inside of the J29s standard wings) were lost and only 2.150l in the Saab 29’s standard fuselage tanks could be carried – but this was, for a research aircraft, not regarded as a major weakness, and compensated for the wing attachment system’s additional weight. The original wing-mounted pitots were replaced by a single, massive sensor boom attached to the aircraft’s nose above the air intake, slightly set-off to starboard in order to give the pilot an unobstructed view.
The first P29G's maiden flight, marked “Gul Urban” (Yellow U), took place in July 1955. The aircraft behaved normally, even though the center of gravity had markedly shifted backwards and the overall gain of weight made the aircraft slightly unstable along the longitudinal axis. During the initial, careful attempts to break the sound barrier, it soon became apparent that both the original wings as well as the original air intake shape limited the P29G's potential. In its original form, the P29G could only barely pass Mach 1 in level flight.
As a consequence, the second P29G, which had been under conversion from another J29B airframe since mid-1954, received more thorough modifications. The air intake was lengthened and widened, and in order to make it more effective at supersonic speed it received a sharp lip. Wind tunnel tests with the first machine led to a modified tail, too: the fin was now taller and further swept back, the stabilizer was moved to a higher position, resulting in a cruciform layout. The original single-piece stabilizer was furthermore replaced by a two-piece, all-moving construction with a 45° sweep and a thinner profile. This not only improved the aerodynamics at high speed, it also suppressed the longitudinal instability problem, even though this was never really cured.
Due to the even higher all-up weight of the new aircraft, the landing gear was reinforced and the 2nd P29G received an experimental suspension system on its main legs with higher spring travel, which was designed for operations on semi-prepared airfields. This system had actually been designed for the updated J29 fighters (esp. the A32B attack variant), but it was not introduced into series production or the Saab 29E/F conversion program. Despite these massive changes, the P29G designation was retained, and the second machine, carrying the tactical code “Röd Urban” (Red U), was quickly nicknamed “Karpen” (“Carp”), due to its characteristic new intake shape, the long fin and its stocky shape.
The second P29G was ready for flight tests in August 1956, just in time to support the Saab 35’s ongoing development – the aircraft, which was eventually built to meet (and exceed) the Swedish Air Force’s 1949 supersonic interceptor requirement. The modifications proved to be successful and the P29G was, fitted with a 60° sweep wing and in clean configuration, able to achieve a maximum speed of 1.367 km/h (849 mph) in level flight, a formidable achievement (vs. the 1,060 km/h (660 mph) of the late J29F and the 1200 km/h (745 mph) of the J32B interceptor) for the post WWII design.
Several wing shapes and profiles were tested, including sweep angles from 25° to 63° as well as different shapes and profiles. Even though the machines carried provisions for the J29’s standard armament, the 20 mm cannons were normally not mounted and replaced with sensors and recording equipment. However, both machines were temporarily fitted with one or two guns in order to analyze the effects of firing the weapons at supersonic speed. Underwing ordnance was also almost never carried. In some tests, though, light bombs or unguided missiles were carried and deployed, or podded cine cameras were carried.
While the second P29G was used for high speed trials, the first machine remained in its original guise and took over low speed handling tests. Thanks to the unique wing switch mechanism, the supersonic research program could be held within a very tight schedule and lasted until late 1959. Thereafter, the P29Gs’ potential was of little use anymore, and the engine use agreement with the USA put an end to further use of the two aircraft, so that both P29Gs were retired from service in 1960. The 1st machine, outfitted with standard J29F wings and stripped off of its engines, remained in use as an instructional air at Malmslätt air base 1969, while the second machine was mothballed. However, both airframes were eventually scrapped in 1970.
General characteristics:
Crew: 1
Length: 11.66 m (38 ft 2 in) fuselage only,
13,97 m (45 ft 9 in) with pitot boom
Wingspan: varied*; 11.0 m (36 ft 1 in) with standard 25° sweep wings,
10.00 m (32 ft 9 ¾ in) with experimental 45° wings
Height: 4.54m (14 ft 10 ½ in)
Wing area: varied*; 24.15 m² (260.0 ft²) with standard 25° sweep wings
22.5 m² (242.2 ft²) with experimental 45° wings
Empty weight: 5,220 kg (11,500 lb)
Max. takeoff weight: 8,510 kg (18,744 lb)
Powerplant:
2× Westinghouse J34-WE-42 turbojets, each rated at 3,400 lbf (15 kN) dry thrust
and 4,200 lbf (19 kN) with full afterburner
Performance:
Maximum speed: 1.367 km/h (849 mph) were achieved*
Range: 790 km (490 mi)
Service ceiling: up to 17,250 m (56,500 ft)*
Rate of climb: up to 45 m/s (8,850 ft/min)*
*Varying figures due to different tested wing configurations
Armament:
None installed; provisions for 4x 20mm Hispano Mark V autocannon in the lower front fuselage.
Depending on the mounted wing type, various external loads could be carried, including a wide range of light bombs, 75 mm (3 in) air-to-air rockets, 145 mm (5.8 in) anti-armor rockets, 150 mm (6 in) HE (high-explosive) rockets or 180 mm (7.2 in) HE anti-ship rockets. Due to the lack of complex wiring or fuel plumbing, no guided weapons or drop tanks could be mounted, though.
The kit and its assembly:
Sweden is a prolific whiffing territory, and the Saab 29 offers some interesting options. This highly modified Tunnan, which is actually rather a kitbashing than a mere model kit modification, is/was a submission to the “More or less engines” group build at whatifmodelers.com in summer 2019.
I actually had the idea of a two-engine J29 in the back of my mind for a long time, spawned by a resin conversion set for the Hasegawa B-47 Stratojet kit that came with new intakes and exhaust sections for the four engine pods. The single engine pod parts had been spent a long time ago, but the twin engine parts were still waiting for a good use. Could the exhaust fit under/into a Tunnan…?
I even had a Matchbox J29 stashed away for this experiment long ago, as well as some donor parts like the wings, and the GB eventually offered the right motivation to put those things together that no one would expect to work.
So I pulled out all the stuff and started – a rather straightforward affair. Work started with the fuselage, which was, together with the (very nice) cockpit assembled OOB at first, the nose filled with as much lead as possible and with the lower rear section cut away, so the B-47 resin jet nozzles would end up at the same position as the original RM2B exhaust. Due to the pen nib fairing between them, though, the profile of the modified tail became (visually) more massive, and I had to fill some gaps under the tail boom (with styrene sheet and putty). The twin engines also turned out to be wider than expected – I had hoped for straight flanks, but the fuselage shape ended up with considerable bulges behind the landing gear wells. These were created with parts from drop tank halves and blended into the rest of the lower hill with PSR work. In the same wake the area under the fin was sculpted and re-created, too.
At that point it became clear that I had to do more on the fuselage, esp. the front end, in order to keep the aircraft visually balance. A convenient solution became an F-100 air intake, which I grafted onto the nose instead of the original circular and round-lipped orifice – with its sharp lip the Super Sabre piece was even a plausible change! The fuselage shapes and diameters differed considerably, though, more PSR became necessary.
Next came the wings: I had already set apart a pair of trapezoid wings with a 45° sweep angle – these were left over from a PM Model Ta 183 conversion some time ago. With their odd shape and size they were a perfect match for my project, even more so due to the fact that I could keep the original J29 wing attachment points, I just had to shorten and modify the trailing edge area on the fuselage. The result was very conclusive.
With the new nose and the wings in place, the overall proportions became clearer: still tail-heavy, but not unpleasant. At this time I was also certain that I had to modify the tail surfaces. The fin was too small and did not have enough sweep for the overall look, and the stabilizer, with its thick profile, rounded edges and the single, continuous rudder did not look supersonic at all. What followed was a long search in the donor banks for suitable replacements, and I eventually came up with a MiG-15 fin (Hobby Boss) which was later clipped at the top for a less recognizable profile. The stabilizers were more challenging, though. My solution eventually became a pair of modified stabilizers from a Matchbox Buccaneer(!), attached to the MiG-15 fin.
The design problems did not stop here, though: the landing gear caused some more headaches. I wanted to keep the OOB parts, but especially the main legs would leave the aircraft with a very goofy look through a short wheelbase and a rear axis position too much forward. In an attempt to save the situation I attached swing arms to the OOB struts, moving the axis maybe 5mm backwards and widening the track by 2mm at the same time. Not much in total, but it helped (a little, even though the aircraft is still very tail-heavy)
As a final addition – since the original, wing-mounted pitots of the J29 were gone now and would not go well with the wing-switching idea – I gave the P29G a large, nose-mounted pitot and sensor boom, placed on top of the nose. This part come, like the air intake, from an F-100.
Painting and markings:
I tend to be conservative when it comes to liveries for what-if models, and the P29G is no exception. At first, I thought that this build could become an operational supersonic daylight interceptor (the J29G), so that I could give the model full military markings and maybe a camouflage paint scheme. However, this idea would not work: the potential real life window for such an aircraft, based on the Saab 29, would be very narrow. And aircraft development in the late Fifties made quantum leaps within a very short period of time: While the J29A entered service, work on the Mach 2 Saab 35 was already underway – nobody would have accepted (or needed) a Mach 1 fighter, based on late Forties technology, at that time anymore, and there was the all-weather Saab J32B around, too. The update program with new wings and a more powerful afterburner engine was all that could be done to exploit the Tunnan’s potential, resulting in the (real world’s) J29E and F variants.
I eventually decided that the J29G would only be a prototype/research aircraft, consequently called P29G, and through this decision I became more or less settled upon a NMF finish with some colorful markings. Consequently, the model was painted with various shades of metal colors, primarily Polished Aluminum Metallizer from Humbrol, but also with Humbrol 191 and Matt Aluminum Metallizer as well as ModelMaster Steel Metallizer. Around the exhaust section, I also used Revell 91 (Iron) and ModelMaster Exhaust Metallizer. Some single panels and details were painted with Revell 99 (Aluminum), and I also used generic decal material in silver to simulate some smaller access panels. Grey decal sheet was used to simulate covers for the cannon nozzles.
The cockpit interior was painted, according to Saab 29 standard, in a dark greenish-grey (Revell 67), and bluish grey was used inside of the landing gear wells (Revell 57). The pitot boom received black and white stripes.
For markings I let myself get inspired from the real world Saab 29 and 32 prototypes, which were all marked with a colored “U” tactical code on the fin and also on the front fuselage, simply meaning “Utverding” (= “Test”). I found four red decals, and I also gave the aircraft a yellow cheatline, lent from an Airfix F-86D decal sheet. The Swedish roundels come from a generic aftermarket sheet, most stencils were taken from the Revell OOB sheet and a Printscale J29 sheet.
Before the model was sealed with semi-gloss acrylic varnish from Italeri, some grinded graphite was rubbed onto the rear fuselage, adding a metallic shine and simulating exhaust stains.
A thorough conversion – this has rather evolved into a kitbashing than just a kit conversion: not much from the original Matchbox J29 has been left over. But I like the outcome, even though things developed gradually from the simple idea of changing the number of engines on the Tunnan. One thing led to another. The resulting aircraft looks quite plausible, even though I am not totally happy with the landing gear, which appears to be rather far forward, despite surgical measures to mend the situation. The Ta 183 wings are a very good match, though, and I cannot help but recognize a certain French look, maybe due to the cruciform tail and the oval air intake? The P29G could also, with Argentinian marking, have become a revised version of the FMA Pulqui II?
Departing Dublin Airport 29th December 2013, following repaint by Eirtech Aviation. Delivered back across to Hamburg, Germany for further cabin modifications prior delivery to the Bahrain Government.
The 38th and final Boeing 767-400ER produced by Boeing, initially as a military testbed, but later cancelled, and sold to the Government of Bahrain as a VIP transport.
Further information can be found at: en.wikipedia.org/wiki/Boeing_767#767-400ER
Royal Aircraft Establishment (RAE) BAC 1-11-201AC, XX105. Originally delivered as a testbed for the British Aircraft Corporation (BAC) on July 6, 1964. Photograph from my collection. Original photographer unknown.
Rebuilt Avro 707 proposed for the Ministry of Supply VTOL research project ER.143T. Power was I believe from 6 RB108 engines mounted vertically in the centre fuselage with thrust diverters on the rear pair to enable forward thrust.
Contact was won by the Short SC1.
Buffed and polished so you could eat your dinner off her,
US Air Force Boeing C-135C Stratotanker, 61-2669 aka 'Speckled Trout', basks in the sunshine in at the Royal International Air Tattoo, RAF Fairford.
With call sign 'Trout 99' and operated by the 412th FLTS out of Edwards AFB, California, '12699' was used primarily by the Secretary and the Chief of Staff of the Air Force for executive transport requirements.
Her secondary role comprised being a testbed for proposed command and control systems and she was also used to evaluate future transport aircraft design.
'Speckled Trout' refers to both the organization and the aircraft and was chosen in honour of an early program monitor, 'Faye Trout' who was blessed with "a lot of freckles."
'99' was retired in 2006 and replaced by an interim KC-135R until specially modified 63-7980 took up the mantle.
Scanned 35mm transparency taken from atop one of the old photo-buses.
Reshade 0.18.1 Framework Extreme Eyecancer Mod Testbed 0.2B
Blackfire's mod + TOD + Reli2
Ini tweaks + POM enabled
Lite TOD, light shadows, nohud, dof %25-50, adjusted brightess, contrast and gamma + exposure. MSAA Disabled. SSAO enabled.
80º FoV,
Custom helmet mesh lens texture (reworked)
------
Framework Config
SweetFX
{ SMAA
Tonemap
Vibrance
Film Grain
Letterbox }
McFX
{ Fisheye CA }
GemFX
{ LensDirt
Ambient Light + ambient light controls for Bloom, Lens and vibrance + advanced eye adaptation }
& Improved performance again, render mode 8bit
Boeing 737-683
cn: 28297 / ln: 30
ff: 02-03-1998 N1786B
02-03-1998 N35135 rr Boeing testbed for C of A for the B737-600 series
21-01-1999 SE-DNS SAS "Signe Viking" config CY112
28-07-2001 LN-RRY rr SAS "Signe Viking"
02-2005 Painted in SAS Braathens colours as the first 736, and opf SAS Braathens from 01-04-2005 (allthough AoC change to CNO was officially made 20-04-2006 for LN-RRY ).
01-07-2007 LN-RRY SAS Norge tfd, "Signe Viking", op in SAS Braathens colours,
SAS Norge colour update was not before 12-2008 (!)
01-10-2009 Scandinavian Airlines - SAS tfd, "Signe Viking" config CY120
Again: LN-RRY did not get updated to std SAS colours before 2013 (!)
07-08-2019 wfu and std ENGM/OSL, after 20,5 years in SAS service
27-08-2019 Departed ENGM/OSL at 13:20 pm as SK9121 to St. Athan EGSY/DGX for part-out and scrap
Boeing 747-267B originally delivered to Cathay Pacific during 1980.
Used by Rolls-Royce North America as a flying testbed and seen here at Tucson International in November 2022.
The aircraft was retired from service in mid 2025 and the 'test' engine was being dismantled on site at Tucson in August 2025.
The 44 year old Rolls Royce 747-200 series testbed returning home to Tucson after a 1+ year assignment in Waco, TX.
Note the Trent 1000 Dreamliner engine in the number 2 position and the new Pearl 10X engine for the Dassault Falcon 10X added to its right wing.
Japan Airlines Boeing 787-9 Dreamliner JA861J is on short final for runway 07R in Frankfurt in quite a distance from the spotting position (focal length: 600mm).
c/n 35422 (l/n 139) has had its first flight on 19.11.13 and was used as a testbed by Boeing with the registration N789ZB from 23.04.13 until 09.06.15 when it was transferred to Japan Airlines.
The jet is powered by 2x General Electric GEnx-1B turbofans and has a cabin layout with 44x Business, 35x Premium Economy and 116x Economy Class seats.
This is flight JL407 from Tokyo (NRT).
ex Thunderbird Aviation Douglas ERA-3B Skywarrior 142668/ N163TB.
These 'Whales' as they were known were ex United States Navy and subsequently operated by Hughes and Thunderbird Aviation and here they were all sitting in the desert sun awaiting their fate at Mojave Airport, Ca
18th October 1996
Sad to think most eventually succumbed to the scrapman!
35mm scanned transparency
Best on black by pressing L
BULLSEYE MEMBERS PLEASE READ: This is just a gun there I put some ideas for parts together it is not the final weapon.
BOE57A Returning from a test flight. This is the first 757 Prototype now used as a testbed by Boeing with an F-22 Nosecone and avionics. Nicknamed the "Catfish." This is the first time it has come to PMD in the recently repainted retro scheme.
+++ DISCLAIMER +++
Nothing you see here is real, even though the conversion or the presented background story might be based on historical facts. BEWARE!
Some background:
The Folland 150 was directly inspired by the (modest) successes experienced by the Saro SR./A.1, a jet-powered flying boat fighter that went through trials in the late 1940ies.
The project had been kicked-off in the end phase of the 2nd World War, when the Imperial Japanese Navy with seaplane fighters such as the Nakajima A6M2-N (an adaptation of the Mitsubishi Zero) and the Kawanishi N1K demonstrated the effectiveness of a fighter seaplane.
In theory, seaplanes were ideally suited to conditions in the Pacific theatre, and could turn any relatively calm area of coast into an airbase. Their main disadvantage came from the way in which the bulk of their floatation gear penalized their performance compared to other fighters.
The new jet engines offered more power and aerodynamically cleaner designs, and the Saro SR./A.1 proved the soundness of the concept. But while the Saro SR./A.1 proved to have good performance and handling, the need for such aircraft had completely evaporated with the end of the war. Furthermore, the success of the aircraft carrier in the Pacific had demonstrated a far more effective way to project airpower over the oceans. The project was suspended and the prototype put into storage in 1950, but it was briefly resurrected in November 1950 owing to the outbreak of the Korean War, before realization of its obsolescence compared with land-based fighters, the prototype last flying in June 1951.
Anyway, this was not the end of the jet-powered flying boat fighter. After the Korean War, Saunders-Roe came up with a design called the "Saunders Roe Hydroski" (reminiscent of the Convair F2Y Sea Dart) to improve the performance closer to land-based aircraft but "received no official support". Other ship-based fighter concepts were developed and proposed, too. In the early Fifties, Folland made several proposals based on its newly developed light fighter, which would evolve into the Gnat.
The Gnat was the creation of WEW "Teddy" Petter, a British aircraft designer formerly of Westland Aircraft and English Electric. It was designed to meet the 1952 Operational Requirement OR.303 calling for a lightweight fighter. Petter believed that a small, simple fighter would offer the advantages of low purchase and operational costs. New lightweight turbojet engines that were being developed enabled the concept to take shape.
In 1951, using company funds, he began work on his lightweight fighter concept, which was designated the "Fo-141 Gnat". The Gnat was to be powered by a Bristol BE-22 Saturn turbojet with 3,800 lbf (16.9 kN 1,724 kgp) thrust. However, the Saturn was cancelled, and so Petter's unarmed proof-of-concept demonstrator for the Gnat was powered by the less powerful Armstrong Siddeley Viper 101 with 1,640 lbf (7.3 kN / 744 kgp) thrust. The demonstrator was designated Fo-139 "Midge".
From this land-based basis, several navalized variants for the use on board of smaller ships were deducted and taken to the hardware stage. The Gnat's selling point was its very small size and low weight, so that it would be easy to handle, operate and stow, even if it was no dedicated carrier.
One development direction focused on rocket-assisted ZELL (Zero-Length-Launch) and conventional landing on land-based airstrips, while another direction reverted to the idea of a light jet-powered flying boat conversion for reconnaissance and (daylight) interception and attack duties.
Both were taken to the hardware stage as private ventures (even though supported by the MoD since both concepts were regarded as fundamental research), and the flying boat project took shape under the handle Folland Fo-150, internally referred to “Project Volans”.
The Fo-150 had only rudimentary similarity with the land-based aircraft, though. Beyond the addition of a hydrodynamic, lower hull, the fuselage was stretched between the cockpit and the wings, for a better CoG distribution. The wing area was increased considerably in order to compensate for the higher all-up weight, improve handling and lower landing speed. The horizontal stabilizers were moved away from the original low position, higher onto a new cruciform tail, in order to keep these surfaces away from spray. The fin itself was slightly enlarged, too.
Power came from a modified Bristol Siddeley Viper turbojet, rated at 3,100 lbf (14 kN). In order to protect the engine from water ingestion the air intakes were extended forward under the cockpit canopy and featured spray dams. Balance in the water was achieved through semi-retractable stabilizer floats. These could be folded backwards under the wings, behind bullet-shaped fairings at about half the wing span that also contained a pair of 30mm Aden cannons. Hardpoints above and under the wings allowed the carriage of light external weapons like unguided rocket pods, or, alternatively, test equipment and camera pods.
The first airframe for Project Volans was built in Folland's facility on the western side of the Hamble peninsula and later taken to the Solent in May 1955. On 14 June 1955, the aircraft inadvertently made its first short flight during a fast taxi run – the enlarged wing created a massive ground effect that easily lifted the light aircraft up into a glide when the nose raised through wakes to a certain degree. The Fo-150’s official maiden flight was on 9 July 1955.
The underpowered engine made the fighter sluggish, and the strong uplift close to the ground made handling complicated and created violent vibration during takeoff and landing. Work on the wings leading edge profile improved this situation somewhat, but they could not cure the sluggish performance.
Otherwise, handling turned out to be good, but the Fo-150 could never show its full potential due to the weak engine. A second airframe was finished until late 1955 and joined the flight tests from early 1956 on, while a third airframe was reserved for static tests.
Anyway, even before that, the Navy had been losing interest (problems with supersonic fighters on carrier decks having been overcome, and ship-based missiles filled the aerial defense role much more efficiently than aircraft). This relegated the Fo-150 and the whole Volans program to pure experimental status. As a consequence, the two airworthy airframes were de-militarized and the aircraft kept in service as testbeds for hydrodynamics, especially for the development of planing bottoms, hydrofoils and hull shapes for high speed ships.
In 1960, WS685 was also used for the development and tests of hydroskis, while its sister ship was retired and used for spares. This program lasted until 1963, and after that, the worn-out airframe was scrapped, too.
General characteristics:
Crew: 1
Length: 10.44 m (34 ft 5 in)
Wingspan: 8,71 m (28 ft 6 in)
Heigh (keel to fin tip)t: 3.74 m (12 ft 3 in)
Wing area: 19.00 m² (204.5 ft²)
Empty weight: 2,560 kg (5,644 lb)
Max. takeoff weight: 4,235 kg (9,336 lb)
Powerplant:
1× Bristol Siddeley Viper turbojet, rated at 3,100 lbf (14 kN)
Performance:
Maximum speed: 695 km/h (375 knots, 432 mph) at sea level
Cruise speed: 324 km/h (175 knots, 201 mph)
Stall speed: 145 km/h (92 knots, 106 mph) with flaps down
Endurance: 1 hour 45 min
Service ceiling: 30,000 ft (9,150 m)
Armament:
2× 30mm ADEN cannon with 80 RPG in underwing pods
Two overwing hardpoints for 500lb (227kg) each,
e.g. for SNEB rocket pods containing seven 68 mm rockets
or pods with 7.62 mm machine guns
Two underwing hardpoints for 500lb (227kg) each,
for bombs or a pair of 50-Imp Gal (226 litre) drop tanks
The kit and its assembly:
Another submission to the 2016 “In the Navy” Group Build at whatifmodelers.com, and actually the consequence of a spontaneous post/comment on another modeler’s project just called “Royal Navy Gnat”, when the means and degree of navalization were still shrouded in mystery. I suggested a flying boat, inspired by the real Saro SR./A.1 and the Gnat’s high-mounted wings, which make the aircraft – or at least a model of it – suitable for a conversion.
Well, since the other Gnat turned out to become a ZELL aircraft, and I had a Matchbox Gnat in the stash, I decided to take my weird alternative idea to the (model) hardware stage.
Even though it is not obvious, pretty much of the Matchbox Gnat was used for this build, but it is masked under lots of putty and donation parts. These include:
- The lower half of a Smer SC-1 Seahawk float – a bit wide, but perfect in length
- The SC-1 also donated its stabilizer floats
- Leftover parts from a vintage (35+ years!) Matchbox F-14’s stabilizers, used as wing extensions
- Air intakes from a Matchbox F-5A, mounted upside down
- Stabilizers from a Hobby Boss MiG-15
The build went pretty straightforward: after the fuselage was done the SC-1 float was trimmed down and glued under it. Putty conceals the seams, and I am actually surprised how good these parts that were surely never meant to be united went together.
The cockpit features only the front seat, the rear position was omitted. The clear canopy was cut into three pieces, and the rear part glued onto the fuselage and blended into the overall shape with putty.
I felt that the deeper fuselage necessitated bigger wings, and instead of mounting complete donation parts I decided to keep the OOB parts and their shape, but extend them slightly with plugs – these are leftover parts from F-14 stabilizers from former projects, their width, length and also the sweep angle were perfect. In order to keep the relative wing tip position, the wing roots had to be moved forward, so that they ended up close to the cockpit and the air intakes. Again, putty conceals the intersections and was used to blend everything into each other – and with the enlarged wings this converted Gnat reminds a bit of the Me 163 Komet rocket fighter? At least, as long as the stabilizers were not mounted yet.
These come from a MiG-15 – bigger than the OOB parts, which appeared just too small for the bigger wing surface and their new position: in order to keep them clear from spray and the waterline I moved them upwards, together with a bullet fairing into the fin, which was simply divided above the rudder. The resulting fin extension was an appreciated extra, and the new cruciform tail looks very retro.
Placing the original air intakes onto the fuselage I found them to be too susceptible to water ingestion, so I wanted to extend them forward. But instead of using the OOB parts and bridging gaps with styrene pieces and putty, I found an old pair of F-5A air intakes with relative long ducts in the spares box. They were of good shape and size for the conversion, I just mounted them upside down, so that the longer leading edge is now on the intakes’ lower end, looking like a spray protector. A pair of spray dams was added to the nose, too.
How to balance the aircraft while afloat caused some headaches. The initial plan had been to place the SC-1 stabilizer floats with their slender pylons close to the wing tips, but I found this to be a very draggy solution for a jet aircraft.
The solution came while wondering where to place some armament: I used the Gnat’s (shortened) OOB slipper tanks as integral gun pods and modified their rear end into fairings for a semi-retracting float installation. The respective struts were scratched from wire and styrene.
The beaching trolley was highjacked from a vintage Revell F-16 kit (the rather clumsy one that represents the prototypes and which comes with a separate jet engine, its dolly and a small tractor). It was slightly modified and lowered, paper tissue cushions hold the model in place.
Painting and markings:
Since the flying boat version of the tiny Gnat (even if is based on the bigger trainer version!) is already exotic enough I decided to keep the livery true to the post WWII Royal Navy style, with Extra Dark Sea Grey upper surface, Sky undersides and a high waterline. In this case, Humbrol 123 and 95 are the basic tones, later treated with a black ink wash, panel lines drawn with a pencil and some panel shading with Humbrol 79 and 23, respectively. The planning surfaces were in the first place painted/primed with acrylic aluminum, so that later the enamel paint cover could be chipped away, for a lightly worn look.
The cockpit interior was painted in very dark grey (Humbrol 32). Thankfully, no landing gear had to be built and painted, but instead the custom beaching trolley became trainer yellow.
The RN markings come from various sources, and finally the kit was sealed under a coat of semi-matt acrylic varnish.
A funny project, and despite the weird idea and combination of parts the result does not look bad at all – in fact, one could think that it is a design or prop from a 1960’s James Bond movie or a Gerry Anderson creation?
N125SC
Eurocopter AS350B2 AStar
Standard Aero (Alliance)
Built 2005
C/N 3904
Outside their new big hangar, registered to what I presume is head office in Maryville TN, used as a testbed for the Thales 4-Axis autopilot. Previously N680DD and N680DG with the Hillsborough County Sheriff.
After being fire damaged, DW411 was chosen for extensive trials, being absent in Ireland for a considerable time. It now features a Mercedes engine, which Wright fitted as part of the Streetdeck development. Now back in service, Enfield often allocate it to the 307, something they won't be able to do much longer with the route lost to Metroline. The bus is seen in Enfield after I alighted. It seemed fit for purpose while not very exciting, though sounded a bit better than a B9. 7/9/15.
"Voodoo 1" on final for a runway 26L landing at Ontario. It's been some time since I last saw this avionics testbed, which has now relocated here from its previous home base at LAX.
Built in 1952 and delivered to the USAF as 52-5784 then to USCG as 5784 from 1977-1984. In 1987 this Convair was used by NASA as a Space Shuttle Crew Escape System testbed. It was fitted with a CES (Crew Escape System) mockup on the left side of the rear fuselage. The aircraft was stored here at California City Municipal Airport in 1993, and preserved in 1997
16-10-2025
This aircraft served as a testbed for a possible RR Avon-powered Mirage for Australia. In the end, the RAAF opted for the standard SNECMA Atar engine. Later it flew with the French CEV on refuelling trials.
Arriving into Dublin Airport 2nd March 2024, from Phoenix, Arizona via Portsmouth, for several days operating flights to and from Munich, Germany.
Delivered new in February 1983, this aircraft was number 5 of an eventual 1,050 built to Eastern Airlines as N504EA, G-JALC with Airtours International & Mytravel Airways until October 2005 when Honeywell International purchased her and converted her for use as an engine test bed.
Former Leeds City Transport (no. 517) and WYPTE Roe bodied Daimler CVG6LX/30 7517 UA was used by Dennis Motors as a testbed for the planned driveline of the Dominator. It was fitted with a Gardner 6LXB engine and Voith automatic gearbox. It was used by SYPTE in Sheffield for several months in 1976.
"Test Garden: The testing section holds several concurrent independent trial programs, each one spanning two years. • American Rose Society Award of Excellence Miniature Trials (AOE): Established in 1975, this garden is one of only six testing grounds of miniflora and miniature roses for the American Rose Society (ARS) miniature rose test program. • American Garden Rose Selection (AGRS): This garden is one of 12 sites in the United States used for new rose testing. This national rose evaluation system recognizes roses on several attributes including vigor, foliage proportion, plant habit, flowering effect and bloom abundance, rebloom habit, bloom form, aging quality, fragrance, and weather hardiness. No spraying occurs on these roses." www.portlandoregon.gov
"The International Rose Test Garden is a rose garden in Washington Park in Portland, Oregon, United States. There are over 10,000 rose bushes of approximately 650 varieties. The roses bloom from April through October with the peak coming in June, depending on the weather. New rose cultivars are continually sent to the garden from many parts of the world and are evaluated on several characteristics, including disease resistance, bloom formation, color, and fragrance. It is the oldest continuously operating public rose test garden in the United States and exemplifies Portland's nickname, "City of Roses". The garden draws an estimated 700,000 visitors annually." wiki
In the late 80's a 767-200 was modified with large cupola on top of the fuselage that housed dual infrared sensor arrays for tracking targets. While the mission was completely different, the function is not unlike NASA's SOFIA 747SP flying telescope. The high altitude of flight eliminates much of the IR-blocking atmosphere from obscuring targets. N767BA was the testbed. It never went beyond the prototype stage and the airframe was eventually scrapped. SDC = Strategic Defense Command.
3.5" across
Railfreight metals liveried 37903 seen at Newport Godfrey Road.
This angle clearly shows the re-profiled roof panels, angled to suit the Mirrlees MB275T power unit inside.
In 1986, four Class 37s, numbers 150/148/249/124, were converted to test the Mirrlees MB275T engine and Brush alternator for the proposed Class 38, and were numbered 37901-4. These were followed in 1987 by 37905/6, converted from 37136/206, and fitted with the alternative pairing of a Ruston RK270T engine and GEC alternator. All six locomotives were fitted with new bogies, and had ballast weights to increase their overall weight to 120 tons. Although intended as a testbed for the Class 38, the two power units fitted were those considered for the Class 60, which was eventually delivered with an enlarged version of the Mirrlees MB275T. They all had modifications similar to that of Class 37/7, including new nose grilles, removal of the central bodyside windows and 4 fire extinguisher ports. However, 37901-904 had a heavily modified central roof section, consisting of flat panels rather than the curved sheets of the original. All 6 had a new exhaust port fitted, replacing the two of the original design.
All six Class 37/9s were delivered in Railfreight Grey livery and operated as part of the British Rail Heavy Metals sector, being based in South Wales and hauling trains normally rostered for the much more powerful Class 56 such as the Port Talbot Steelworks - Llanwern Iron Ore tipplers.
During the late 1990s, use of the Class 37/9s declined due to availability of the newer and more powerful Class 66s and problems maintaining such a small number of non-standard locos, with all six officially designated as being in storage in 1999.
This was not, however, the end of the sub-class. In July 2000, 37906 was designated as part of the EWS heritage fleet but has since been sold into preservation, joining 37901 and 37905. 37902 was sold to Direct Rail Services in 2003, but was scrapped and cut up in 2005 after a review by DRS. 37904 was cut up at Booths in Rotherham in November 2004 and 37903 was scrapped at Crewe Diesel TMD in April 2005. As of October 2010, 37906 is still fully functional and in preservation.
+++ DISCLAIMER +++
Nothing you see here is real, even though the conversion or the presented background story might be based historical facts. BEWARE!
Some background:
The Northrop Grumman-IAI F-24 is the latest reincarnation of the USAF "Lightweight Fighter Program" which dates back to the 1950ies and started with the development of Northrop's F-5 "Freedom Fighter".
The 1st generation F-5 became very successful in the export market and saw a long line of development, including the much more powerful F-5E "Tiger II" and the F-20 Tigershark (initially called F-5G). Northrop had high hopes for the F-20 in the international market; however, policy changes following Ronald Reagan's election meant the F-20 had to compete for sales against aircraft like the F-16, the USAF's latest fighter design (which was politically favored). The F-20 development program was eventually abandoned in 1986 after three prototypes had been built and a fourth partially completed.
But this was not the end for Northrop’s Lightweight Fighter. In the early 1980s, two X-29As experimental aircraft were built by Grumman from two existing Northrop F-5A Freedom Fighter airframes. The Grumman X-29 was a testbed for forward-swept wings, canard control surfaces, and other novel aircraft technologies. The aerodynamic instability of this arrangement increased agility but required the use of computerized fly-by-wire control. Composite materials were used to control the aeroelastic divergent twisting experienced by forward-swept wings, also reducing the weight. The NASA test program continued from 1984 to 1991 and the X-29s flew 242 times, gathering valuable data and breaking ground for new aerodynamic technologies of 4th and 5th generation fighters.
Even though no service aircraft directly evolved from the X-29, its innovative FBW system as well as the new material technologies also opened the door for an updated F-20 far beyond the 1990ies. It became clear that ever expensive and complex aircraft could not be the answer to modern, asymmetrical warfare in remote corners of the world, with exploding development costs and just a limited number of aircraft in service that could not generate true economies of scale, esp. when their state-of-the-art design would not permit any export.
Anyway, a global market for simpler fighter aircraft was there, as 1st generation F-16s as well as the worldwide, aging F-5E fleet and types of Soviet/Russian origin like the MiG-29 provided the need for a modern, yet light and economical jet fighter. Contemporary types like the Indian HAL Tejas, the Swedish Saab Gripen, the French Dassault Rafale and the Pakistani/Chinese FC-1/JF-17 ”Thunder” proved this trend among 4th - 4.5th generation fighter aircraft.
Northrop Grumman (Northrop bought Grumman in 1994) initiated studies and basic design work on a respective New Lightweight Fighter (NLF) as a private venture in 1995. Work on the NLF started at a slow pace, as the company was busy with re-structuring.
The idea of an updated lightweight fighter was fueled by another source, too: Israel. In 1998 IAI started looking in the USA for a development partner for a new, light fighter that would replace its obsolete Kfir fleet and partly relieve its F-16 and F-15 fleet from interception tasks. The domestic project for that role, the IAI Lavi, had been stillborn, but lots of its avionics and research were still at hand and waited for an airframe for completion.
The new aircraft for the IAF was to be superior to the MiG-29, at least on par with the F-16C/D, but easier to maintain, smaller and overall cheaper. Since the performance profiles appeared to be similar to what Northrop Grumman was developing under the NLF label, the US company eventually teamed up with IAI in 2000 and both started the mutual project "Namer" (=נמר, “Tiger” in Hebrew), which eventually lead to the F-24 I for the IAF which kept its project name for service and to the USAF’s F-24A “Tigershark”.
The F-24, as the NLF, was based on the F-20 airframe, but outwardly showed only little family heritage, onle the forward fuselage around the cockpit reminds of the original F-5 design . Many aerodynamic details, e. g. the air intakes and air ducts, were taken over from the X-29, though, as the experimental aircraft and its components had been developed for extreme maneuvers and extra high agility. Nevertheless, the X-29's forward-swept wing was considered to be too exotic and fragile for a true service aircraft, but the F-24 was to feature an Active Aeroelastic Wing (AAW) system.
AAW Technology integrates wing aerodynamics, controls, and structure to harness and control wing aeroelastic twist at high speeds and dynamic pressures. By using multiple leading and trailing edge controls like "aerodynamic tabs", subtle amounts of aeroelastic twist can be controlled to provide large amounts of wing control power, while minimizing maneuver air loads at high wing strain conditions or aerodynamic drag at low wing strain conditions. This system was initially tested on the X-29 and later on the X-53 research aircraft, a modified F-18, until 2006.
Both USAF and IAF versions feature this state-of-the-art aerodynamic technology, but it is uncertain if other customers will receive it. While details concerning the F-24's system have not been published yet, it is assumed that its AAW is so effective that canard foreplanes could be omitted without sacrificing lift and maneuverability, and that drag is effectively minimized as the wing profile can be adjusted according to the aircraft’s speed, altitude, payload and mission – much like a VG wing, but without its clumsy and heavy swiveling mechanism which has to bear high g forces. As a result, the F-24 is, compared to the F-20, which could carry an external payload of about 3.5 tons, rumored to be able to carry up to 5 tons of ordnance.
The delta wing shape proved to be a perfect choice for the required surface and flap actuators inside of the wings, and it would also offer a very good compromise between lift and drag for a wide range of performance. Anyway, there was one price to pay: in order to keep the wing profile thin and simple, the F-24’s landing gear retracts into the lower fuselage, leaving the aircraft with a relatively narrow track.
Another major design factor for the outstanding performance of this rather small aircraft was weight reduction and structural integrity – combined with simplicity, ruggedness and a modular construction which would allow later upgrades. Instead of “going big” and expensive, the new F-24 was to create its performance through dedicated loss of weight, which was in some part also a compensation for the AAW system in the wings and its periphery.
Weight was saved wherever possible, e .g. a newly developed, lightweight M199A1 gatling gun. This 20mm cannon is a three-barreled, heavily modified version of the already “stripped” M61A2 gun in the USAF’s current F-18E and F-22. One of the novel features is a pneumatic drive instead of the traditional electric mechanism, what not only saves weight but also improves trigger response. The new gun weighs only a mere 65kg (the six-barreled M61A2 weighs 92kg, the original M61A1 112 kg), but still reaches a burst rate of fire of 1.800 RPM (about 800 RPM under cyclic fire, standard practice is to fire the cannon in 30 to 50-round bursts, though) and a muzzle velocity of 1.050 metres per second (3,450 ft/s) with a PGU-28/B round.
While the F-16 was and is still made from 80% aluminum alloys and only from 3% composites, the F-24 makes major use of carbon fiber and other lightweight materials, which make up about 40% of the aircraft’s structure, plus an increased share of Titanium and Magnesium alloys. As a consequence and through many other weight-saving measures like keeping stealth capabilities to a minimum (even though RAM was deliberately used and many details designed to have a natural low radar signature, resulting in modest radar cross-section (RCS) reductions), a single, relatively small engine, a fuel-efficient F404-GE-402 turbofan, is enough to make the F-24 a fast and very agile aircraft, coupled with a good range. The F-24’s thrust/weight ratio is considerably higher than 1, and later versions with a vectored thrust nozzle (see below) will take this level of agility even further – with the pilot becoming the limiting factor for the aircraft’s performance.
USAF and IAF F-24s are outfitted with Northrop Grumman's AN/APG-80 Active Electronically Scanned Array (AESA) radar, also used in the F-16 Block 60 aircraft. Other customers might only receive the AN/APG-68, making the F-24 comparable to the F-16C/D.
The first prototype, the YF-24, flew on 8th of March 2008, followed by two more aircraft plus a static airframe until summer 2010. In early 2011 the USAF placed an initial order of 101 aircraft (probably also to stir export sales – the earlier lightweight fighters from Northrop suffered from the fact that the manufacturer’s country would not use the aircraft in its own forces). These initial aircraft will replace older F-16 in the interceptor role, or free them for fighter bomber tasks. The USN and USMC also showed interest in the aircraft for their aggressor squadrons, for dissimilar air combat training. A two-seater, called the F-24B, is supposed to follow soon, too, and a later version for 2020 onwards, tentatively designated F-24C, is to feature an even stronger F404 engine and a 3D vectoring nozzle.
Israel is going to produce its own version domestically from late 2014 on, which will exclusively be used by the IAF. These aircraft will be outfitted with different avionics, built by Elta in Israel, and cater to national requirements which focus more on multi-purpose service, while the USAF focusses with its F-24A on aerial combat and interception tasks.
International interest for the F-24A is already there: in late 2013 Grumman stated that initial talks have been made with various countries, and potential export candidates from 2015 on are Taiwan, Singapore, Thailand, Finland, Norway, Australia and Japan.
General F-24A characteristics:
Crew: 1 pilot
Length: 47 ft 4 in (14.4 m)
Wingspan: 27 ft 11.9 in / 8.53 m; with wingtip missiles (26 ft 8 in/ 8.13 m; without wingtip missiles)
Height: 13 ft 10 in (4.20 m)
Wing area: 36.55 m² (392 ft²)
Empty weight: 13.150 lb (5.090 kg)
Loaded weight: 15.480 lb (6.830 kg)
Max. take-off weight: 27.530 lb (12.500 kg)
Powerplant:
1× General Electric F404-GE-402 turbofan with a dry thrust of 11,000 lbf (48.9 kN) and 17,750 lbf (79.2 kN) with afterburner
Performance
Maximum speed: Mach 2+
Combat radius: 300 nmi (345 mi, 556 km); for hi-lo-hi mission with 2 × 330 US gal (1,250 L) drop tanks
Ferry range: 1,490 nmi (1715 mi, 2759 km); with 3 × 330 US gal (1,250 L) drop tanks
Service ceiling: 55,000 ft (16,800 m)
Rate of climb: 52,800 ft/min (255 m/s)
Wing loading: 70.0 lb/ft² (342 kg/m²)
Thrust/weight: 1.09 (1.35 with loaded weight & 50% fuel)
Armament
1× 20 mm (0.787 in) M199A1 3-barreled Gatling cannon in the lower fuselage with 400 RPG
Eleven external hardpoints (two wingtip tails, six underwing hardpoints, three underfuselage hardpoints) and a total capacity of 11.000 lb (4.994 kg) of missiles (incl. AIM 9 Sidewinder and AIM 120 AMRAAM), bombs, rockets, ECM pods and drop tanks for extended range.
The kit and its assembly:
A spontaneous project. This major kitbash was inspired by fellow user nighthunter at whatifmodelers.com, who came up with a profile of a mashed-up US fighter, created “out of boredom”. The original idea was called F-21C, and it was to be a domestic successor to the IAI Kfirs which had been used by the US as aggressor aircraft in USN and USMC service for a few years.
As a weird(?) coincidence I had many of the necessary ingredients for this fictional aircraft in store, even though some parts and details were later changed. This model here is an interpretation of the original design. The idea was spun further, and the available parts that finally went into the model also had some influence on design and background.
I thank nighthunter for sharing the early ideas, inviting me to take the design to the hardware stage (sort of…) and adapting my feedback into new design sketches, too, which, in return, inspired the model building process.
Well, what went into this thing? To cook up a F-24 à la Dizzyfugu you just need (all in 1:72):
● Fuselage from a Hasegawa X-29, including the cockpit and the landing gear
● Fin and nose cone from an Italeri F-16A
● Inner wings from a (vintage) Hasegawa MiG-21F
● Outer wings from a F-4 (probably a J, Hasegawa or Fujimi)
The wing construction deviates from nighthunter’s original idea. The favorite ingredients would have been F-16XL or simple Mirage III wings, but I found the composite wing to be more attractive and “different”. The big F-16XL wings, despite their benefit of a unique shape, might also have created scale/size problems with a F-20 style fuselage? So I built hybrid wings: The MiG-21 landing gear wells were filled with putty and the F-4 outer wings simply glued onto the MiG inner wing sections, which were simply cut down in span. It sounds like an unlikely combo, but these parts fit together almost perfectly! In order to hide the F-4 origins I modified them to carry wingtip launch rails, though, which were also part of nighthunter’s original design.
The AAW technology detail mentioned in the background came in handy as it explains the complicated wing shape and the fact that the landing gear retracts into the fuselage, not into the wings, which would have been more plausible… Anyway, there’s still room for a simpler export version, with Mirage III or Kfir C.2/7 wings, and maybe canards?
Using the X-29 as basis also made fitting the new wings onto the area-ruled fuselage pretty easy, as I could use the wing root parts from the X-29 to bridge the gap. The original, forward-swept wings were just cut away, and the remains used as consoles for the new hybrid delta wings. Took some SERIOUS putty work, but the result is IMHO fine.
The bigger/square X-29 air intakes were taken over, and they change the look of the aircraft, making it look less F-5-ish than a true F-20 fuselage. For the same reason I kept the large fairing at the fin base, combining it with a bigger F-16 tail, though, as a counter-balance to the new, bigger wings. Again, the F-16 fin was/is part of nighthunter’s idea, so the model stays true to the original concept.
For the same reason I omitted the original X-29 nose, which is rather pointy, sports vanes and a large sensor boom. The F-16 nose was a plausible choice, as the AN/APG-80 is also carried by late Fighting Falcons, and its shape fits well, too.
All around the hull, some small details like radar warning sensors, pitots and air scoops were added. Not really necessary, but such thing add IMHO to the overall impression of such a fictional aircraft beyond the prototype stage.
Cockpit and landing gear were taken OOB, I just added a pilot figure and slightly modified the seat.
The ordnance was puzzled together from the scrap box, the AIM-9Ls come from the same F-4 kit which donated its outer wings, the AIM-120s come from an Italeri NATO weapons kit. The drop tanks belong to an F-16.
Painting and markings:
At first I considered an F-24I in IAF markings, or even a Japanese aircraft, but then reverted to one of nighthunter’s initial, simple ideas: an USAF aircraft in the “Hill II” paint scheme (F-16 style), made up from three shades of gray (FS 36118, 36270 and 36375) with low-viz markings and stencils. Dutch/Turkish NF-5A/Bs in the “Hill II” scheme were used as design benchmarks, too. It’s a simple livery, but on this delta wing aircraft it looks pretty interesting. I used enamels, what I had at hand: Humbrol 127 and 126, and Modelmaster's 1723.
A light black ink wash was applied, in order to em,phasize the engraved panel lines, in contrast to that, panels were manually highlighted through dry-brushed, lighter shades of gray (Humbrol 27, 166 and 167).
“Hill II” also adds to a generic, realistic touch for this whif. Doing an exotic air force thing is rather easy, but creating a convincing whif for a huge military machinery like the USAF’s takes more subtlety, I think.
The cockpit was painted in medium Gray (Dark Gull Grey, FS 36231, Humbrol 140), as well as the radome. The landing gear and the air intakes were painted white. The radome was painted with Revell 47 and dry-brushed with Humbrol 140.
Decals were puzzled together from various USAF aircraft, including sheets from an Airfix F-117, an Italeri F-15E and even an Academy OV-10D.
Tadah: a hardware tribute to an idea, born from boredom - and the aircraft does not look even bad at all? What I wanted to achieve was to make the F-24 neither look like a F-20, nor a Saab Gripen clone, as the latter comes close in overall shape, size and design.
On July 19, 2013, Lockheed Martin’s full-sized, functional GPS III satellite prototype arrived at Cape Canaveral Air Force Station (CCAFS), Fla., aboard a C-17 aircraft from Buckley Air Force Base outside of Denver, Colo. Lockheed Martin delivered the GPS III Non-Flight Satellite Testbed (GNST) to the Cape so that CCAFS’s facilities and pre-launch processes could be tested, further reducing risk and gaining efficiencies, prior the first GPS III flight satellite’s expected delivery to the U.S. Air Force in 2014 and launch in 2015.