Utilized photos on Flickr

1:72 Saab P29G “Kurviga Tunnan” a.k.a. “Karpen“; 2nd prototype “Röd Urban” (s/n 29488), fitted with experimental 45° wings, Swedish Air Force during high speed trials; Malmslätt, Sweden, summer 1959 (Whif/Matchbox kit conversion) by Dizzyfugu

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+++ 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?

Contax AX with Carl Zeiss Vario-Sonnar 28 - 85mm f/3.3 - 4.0 (MMJ) by Timothy Rogers

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The AX is the first autofocus Contax SLR produced by Kyocera. The AX achieves autofocus capability with the standard manual focus Carl Zeiss lenses by utilizing a specially-developed automatic back focusing system. With this system, the fixed mirror box, pentaprism assembly and film plane move as a unit along a ceramic rail to achieve focus. Contax later introduced the N1/NX series of autofocus film SLRs that used a new generation of autofocus Carl Zeiss lenses. The later model N1 and NX are not compatible with manual focus Contax/Yashica mount Carl Zeiss and Yashica lenses.

Being a long-time manual focus SLR user when the AX first came out, I at first did not know how to react to this camera. Recall at the time that many photographers were still shooting manual focus SLRs, such as the Nikon F3, Contax ST,etc. The AX generated a lot of commentary in the press and especially on the Internet soon after its release. Some thought it was great that Contax took this approach to finally develop an autofocus SLR. Others though this was an admission of defeat by a camera maker that waited far too long to get onto the autofocus SLR bandwagon. Looking back from a historical standpoint, the AX was a brilliant solution by Kyocera to try to compete in the autofocus SLR market while maintaining compatibility with their existing base of Contax line Carl Zeiss lenses. In a way, the RX and AX were stepping stones by Kyocera on their way from traditional manual focus to a complete autofocus system with the N1/NX.

For those who are used to the image of sleek, thin SLRs such as the RX and the ST, the AX does not immediately appear to be beautiful. The camera has the cosmetics of an RX, but the AX body is much thicker from front to back to make room for the moving focus assembly within the camera. However, once one gets used to the camera's bulky image, at least for a 35mm SLR, one realizes that it is packed with useful technology and really does combine the best features of automatic focus capabilities and compatibility with Carl Zeiss manual focus lenses.

The AX continued the tradition of providing the tank-like over-engineered feel common to most Contax bodies. The camera has a titanium top cover and an aluminum alloy die-cast chassis, and is made with the same attention to detail and finely-machined parts for which Contax cameras are renowned. All of the controls are consistent with the design of other high-end Contax cameras, employing the switches and knobs representative of a traditional analog user interface but which are actually electronic controls connected to state-of-the-are electronic circuitry within the camera. The camera weighs in at 1,080 grams without battery, so it is no lightweight. However, its weight is still acceptable when compared with certain other contemporaneous professional-level bodies from Contax (RTSIII), Nikon (F4 and F5) and others, especially after battery weight is factored in.

Let's check out the various features of this fascinating camera. Basically, the designers have successfully combined the best and most important features of the RX, ST and RTSIII, and then gone a step further by adding autofocus. The AX has a shutter speed dial positioned at the standard Contax location on the top left of the camera. While shutter speed can only be set from 4 sec. to 1/4000 sec. in manual and shutter priority mode, the shutter has an increased range from 32 sec. to 1/6000 sec. in Av and P modes. Surrounding the shutter speed dial is an exposure mode selector lever, which permits selection of the following metering modes: Av, Tv, P, M, X and B. The same lever is also used for selecting modes to directly adjust film ISO and to modify the custom functions of the camera. Custom functions such as film leader out on rewind are actually set using the two adjustment buttons on the top right of the camera. The AX has the standard Contax exposure compensation dial on the top right of the camera, which allows very easy and quick adjustment of exposure compensation in the range of +-2 EV. The exposure compensation dial is surrounded by the automatic bracketing control ("ABC") lever, which permits a series of three photographs to be taken with +- 0.5 or 1.0 EV exposure compensation. The ABC function works either by making one exposure with each press of the shutter release button, or a continuous burst of three frames as long as the shutter release button is held down, depending on how the drive mode selector dial is set (single or continuous exposure). The top-mounted drive mode selector dial allows adjustment for single frame exposure, continuous exposure (at 3 or 5 fps), multiple exposure, and self timer (2 or 10 second delay). Surrounding the drive mode selector dial is the focus mode selector lever. This lever allows rapid selection among manual focus, single autofocus, continuous autofocus, and a macro setting. A combination button/dial just under the thumb position on the back right of the camera body works with the focus mode selector lever to adjust the operation of the focus system. The main switch surrounding the shutter release button has the usual Contax autoexposure lock functionality. However, the AX adopts the RTSIII's very convenient placement of the exposure meter selection switch to the left side of the lens mount. Other controls include the standard Contax exposure check button and electronic depth-of-field preview button on the right front of the camera. The exposure check button activates the viewfinder information without the risk of tripping the shutter when trying to press the shutter release button down only half-way. The camera also provides built-it dioptric adjustment and a shutter for the viewfinder eyepiece.

The viewfinder of the AX is very good. The camera uses an oversized prism, providing a very bright view of the subject and a 95% field of view. While it is an autofocus camera, the AX, like the RX, also sports the traditional horizontal split image, microprism collar, and of course matte field optical focusing aids. All of the viewfinder readouts are located on a LCD display below the viewfinder image. This display includes an exposure frame counter, spot/average metering indicator, exposure compensation indicator (+ or -, as well as a numerical readout of the amount of compensation), flash indicator, back focus position indicator, in-focus indicator, aperture indicator, over/under exposure warning, and shutter speed indicator. Because of the packed real estate on the viewfinder LCD readout, there is unfortunately no room for a graphical indication of the exact amount of exposure compensation, or any indication of the amount of over/under exposure when setting exposure in M mode. Metering patterns are a 5 mm spot meter, which includes the area within the microprism focusing collar, and a wide area center-weighted average pattern. In addition to the standard FW-1 focusing screen, Contax also provides four other selections of focusing screens for various applications.

The flash functionality of the AX combines the best features of both the RX and the ST, but does not offer the pre-flash spot meter found on the RTSIII. Flash synch is at a fastest speed of 1/200 second. Among Contax electronic cameras, only the RTSIII offers a faster maximum synch speed (1/250 second). This speed should be fast enough for fill flash in most available light conditions. TTL flash appears to be based on a fairly narrow center-weighted pattern. The AX shares the RX's five-point flash contact on the accessory shoe, providing enhanced camera to flash communication, as well as a locking slot to keep the flash unit from falling off. With this improved communication, the Contax TLA flash readout panel will automatically reflect the film ISO and lens aperture, as well as activate the direct flash exposure compensation functionality on the flash unit itself. With this system, balanced fill flash is implemented by setting the appropriate negative flash compensation on the flash unit.

The AX can be fit with an optional multi-functional data back (D-8). This highly advanced data back allows the recording of data (such as shutter speed and aperture, date, time or exposure mode) between the film frames or on frames one and two at the beginning of the roll. Somewhat uniquely in its class, the D-8 also provides an intervalometer that can be set to trigger exposures from every two seconds to 99 hours, 59 minutes, 59 seconds.

The AX works on one 6V lithium 2CR5 battery. The battery is inserted on one side of the camera base, allowing the tripod mount of this relatively weighty camera to be placed at the body's center of balance. Kyocera claims that the battery has a capacity of about 50 rolls of 36-exposure film under their test conditions. The automatic back focusing system of the AX appears to be relatively energy-efficient. As I mentioned in my separate review for the RX, I prefer the use of lithium batteries in Contax cameras, which provides for longer time between battery changes, better cold weather performance, and lighter travelling weight.

The autofocus system of the AX utilizes an AF-assist beam, which is emitted from the right front of the camera. The camera’s autofocus capability is relatively fast and accurate for general use, especially for the time when the AX was released. It was not as fast as the autofocus systems on high-end sports-oriented cameras, such as the Nikon F5 or the Canon EOS 1n. Nevertheless, the AX's focusing speed and accuracy compared very favorably with other autofocus bodies offered by the competition. A very nice feature of the AX's autofocus system is its ability to turn almost any lens into a macro lens (by eliminating the need to use extension tubes). In normal (non-macro) autofocus mode, some care must be taken when focusing floating element/group lenses at relatively close distances.

Carl Zeiss Vario-Sonnar 28-85/3.3-4.0

The Carl Zeiss Vario-Sonar T* 28-85mm f/3.3-4 (MMJ) is an amazing precision work of metal and glass. This lens provides one of the most popular zoom ranges with photographers, and is also my favorite zoom range in the 35mm film world. I use this lens when I only want to carry one Carl Zeiss lens on a trip or outing and the 50/1.4 by itself won't do. The 29-75 degree angular field will cover you in most everyday situations. The f/3.3-4 maximum aperture range is not the greatest, but it is acceptable for normal use. (I generally won't use a zoom lens if the maximum aperture is smaller than f/4.) Anyway, this lens is already about maximum acceptable size and weight for hand-held use, and that is the purpose for which this lens was designed. Imagine how big and heavy the lens would be if it had larger maximum aperture! The lens is engineered in two parts; the rear barrel is fixed to the camera and includes the aperture ring. The front barrel twists for focus and slides in and out for zoom. The lens is at maximum length when it is zoomed to 28mm.

If you are using a Contax AX, you even get autofocus with all of your CZ lenses. Normally, you just set the lens focus to infinity and the AX autofocus function takes it from there. However, this lens if one of a few CZ lenses where you need to move the lens off of infinity to autofocus at the minimum end of the range, which is not a big deal. The focus/zoom movement is silky smooth.

The CZ 28-85/3.3-4 does have some disadvantages. It does not work well on a tripod, with the single ring design and lack of a tripod socket. It can be used on a sturdy-tripod with a heavier Contax body to support and balance the lens, but however irrationally, I would avoid doing it too much to avoid stressing the bayonet and mount on the lens and camera. (As mentioned in the introduction to the Carl Zeiss lens section, the metal mounting ring on the lens is relatively thin compared with the weight of CZ lenses and can be damaged if stressed too much. Indeed, I once damaged the mount of this lens by twisting it on while it wasn't exactly perpendicular to the camera body. Another disadvantage of the single ring design is that it is difficult to adjust the focus without nudging the zoom and vice versa. When carried over your shoulder while attached to the a camera body, the lens will always zoom out to maximum wide angle due to the weight of the front barrel. I have a habit of zooming the lens all the way out before slinging the camera over my shoulder. (Don't sling it around your neck, especially when attached to an RTSIII or you may cut off all blood flow to your brain! Still, its size and weight is about the same as a modern large-aperture autofocus zoom lens.)

I once had the infinity focus of this lens go out of adjustment. I couldn't turn the focusing ring far enough to focus at infinity. A trip to the authorized repair shop solved the focusing problem and above bent bayonet ring problem about 15 years ago, and the lens still appears fine to this day. One other quirk I noticed is that this zoom lens does not communicate the current value of the variable aperture to the camera. Thus if you zoom the lens all the way to telephoto while the lens is set to maximum aperture, for example, the aperture setting displayed in the viewfinder does not change to reflect the actual aperture value. Actually, it does not matter because the light meter still exposes the film properly; only the displayed value is slightly misleading.

How to carry this lens and body combination? As mentioned above, I usually use this lens when it is the only lens that I carry. For this purpose, I have a camera bag that is designed for a modern digital SLR body with a large zoom lens. I can attach this lens to any full-size Contax body and the combination fits in the bag like a glove.

The 28-85/3.3-4 lens takes large screw-in 82mm filters. Contax provided a very nice W-1 metal lens hood, which is matched to the zoom range of the lens and screws right on top of your filter. Also, Contax made a matching metal 99mm K-94 lens cap that snugly fit right on top of the W-1 lens hood. There is never any need to remove the filter and hood from the lens for storage or to use the smaller original lens cap.

(DSC_5699al1br+6cl1br+15cl2cl3 Rev1)

1:72 Saab J29D (Flygande) Tunnan; “Röd Rudolf” of the Swedish Air Force F1 Kungliga Västmanlands Flygflottilj, 1st Jaktflygdivision; Hässlö Flygplats/Västerås, central Sweden, 1964 (Whif/Heller kit conversion) by Dizzyfugu

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+++ 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. This led to a pair of proposals being issued by the Saab design team, led by Lars Brising. The first of these, codenamed R101, was a cigar-shaped aircraft, which bore a resemblance to the American Lockheed P-80 Shooting Star. The second design, which would later be picked as the winner, was a barrel-shaped design, codenamed R 1001, which proved to be both faster and more agile upon closer study.

The original R 1001 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 performed at the Swedish Royal University of Technology and by the National Aeronautical Research Institute 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 single Saab Safir. It received the designation Saab 201 and a full-scale R 1001 wing for a series of flight tests. The first 'final' sketches of the aircraft, incorporating the new information, was 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 instead 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.
On 1 September 1948, the first of the Saab 29 prototypes conducted its maiden flight, which lasted for half an hour. Because of the shape of its fuselage, the Saab J 29 quickly received the nickname "Flygande Tunnan" ("The Flying Barrel"), or "Tunnan" ("The Barrel") for short. While the demeaning nickname was not appreciated by Saab, its short form was eventually officially adopted.

A total of four prototypes were built for the aircraft's test program. The first two lacked armament, carrying heavy test equipment instead, while the third prototype was armed with four 20mm automatic guns. Various different aerodynamic arrangements were tested, such as air brakes being installed either upon the fuselage or on the wings aft of the rear spar, along with both combined and conventional aileron/flap arrangements.
The flight test program revealed that the J 29 prototypes were capable of reaching and exceeding the maximum permissible Mach number for which they had been designed, and the flight performance figures gathered were found to be typically in excess of the predicted values.

In 1948 production of the type commenced 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 and a dedicated all-weather fighter with an on-board radar, the J 29D.

The J 29D variant originally started its career as a single prototype to test the Ghost RM 2A afterburner turbojet with 27.5 kN (2,800 kgp/6,175 lbf). The new engine dramatically improved the Tunnan’s performance, esp. concerning the start phase, acceleration and climb, and was eventually adopted for the whole J 29 fighter fleet in an update program, leading to the J 29F variant.

However, at the time of the RM 2A trials, Sweden was more and more in need for a suitable all-weather aerial defense for its vast, neutral airspace in the vicinity of the Soviet Union. Only a single flight of the Swedish Air Force, F1 in Hässlö, operated roundabout thirty radar-equipped fighters, and these were outdated De Havilland Mosquito night fighters (locally designated J 30).

The highly successful J 29 was soon considered as a potential air-intercept radar carrier, offering a much more up-tp-date performance and deterrent potential against would-be intruders. Consequently, Saab started the development of an indigenous all-weather fighter on the basis of the Tunnan (originally coded “J 29R”). The work started with aerodynamic trials of different radome designs and placements on a Tunnan’s nose, e .g. inside of the circular air intake opening or above it. No major drawbacks were identified, and in 1955 the decision was made to convert thirty J 29B daylight fighters for the all weather/night fighter role. These machines officially inherited the designation J 29D.
The J 29D’s compact radar, called the PS-43/T, was designed by CSF (Compagnie Generale de Telegrahpi Sans Fil) in France after the Swedish specification. It had a wavelength of 3 cm with an effect of 100 kW, and it was to have a spiral scan pattern. Range was 15-20 km, only a slight improved against the Mosquitos’ bulky SCR-720B radar set, which only had a range of 12-16km. But the system’s compact size and the ability to be operated by the pilot alone meant a serious step forward. 34 sets were delivered together with blueprints in 1956, and the PS-43 radar system was later modified and adapted to the Saab 32 Lansen, too.

The structural modifications for the radar-equipped Tunnan were carried out in the course of the ensuing J 29F update program, which had started in 1954. Beyond the afterburner engine and dogtooth wing updates for the day fighters, the J 29D also received a re-designed nose section which now featured a thimble radome for the PS-43/T, integrated into the upper air intake lip, reminiscent of the F-86D’s arrangement. The air intake itself kept the original circular diameter, but the opening was slightly wider, raked forward and featured a sharper lip, for an improved airflow under the radome. Overall performance of the J 29 did not suffer, and the conversion took place swiftly thanks to a simple replacement of the nose section in front of the windscreen and the installation of a shielded tracking monitor in the cockpit.

Experiments with a heavier cannon armament (consisting of four, long-barreled 30mm guns in the lower fuselage) for the J 29 in general were conducted in parallel, too. But, despite showing no negative effect on the J 29’s handling or performance, this upgrade was not introduced to any of the J 29 variants in service and so the J 29D kept its original four 20mm cannon as main armament, too. Additional ordnance consisted of optional racks with 75 mm/3 in air-to-air rockets under the inner wings against large aerial targets like bombers. A pair of drop tanks could be carried on the outer pylons, too, and they were frequently carried in order to extend range and loiter time. Other loads, including bombs or unguided air-to-ground missiles, were possible, but never carried except for in practice.

The last converted J 29D was delivered back to the Swedish Air Force in late 1956, just in time to replace the last active J 30 Mosquitos in service, which had been gradually phased out since 1953. In parallel, the radar-equipped J 33 Venom was introduced into service, too, since the small number of J 29Ds had in the meantime turned out to be far from sufficient to effectively cover the Swedish air space against large numbers of ever faster jet bombers and reconnaissance aircraft. The J 29D fulfilled its role and duty well, though, and was just as popular as the daylight fighter versions.

Initially, all J 29D were delivered in bare metal finish, but they were soon adorned with additional markings on fin and wing tips for easier recognition and formation flights. A few all-weather fighters of F1 Flygflottil experimentally received the blue/green camouflage which had been adopted for the S 29C reconnaissance aircraft, but this was found to be ineffective at the typical altitudes the interceptors would operate. As a consequence, the scheme was quickly changed into the much lighter livery of the former J 30 and J 33 fighters, although the bare metal undersides and the formation markings under the wing tips were retained – even though this practice was confined to F 1 and not consequently carried out among all of the fighter squadron's J 29Ds. Some J 29D furthermore carried various forms of black ID bands for quick identification in war games, but unlike the day fighters, these markings were limited to the undersides only.

From 1963 onwards all frontline J 29Fs were equipped with AIM-9 Sidewinder infrared-seeking air-to-air missiles, designated Rb 24 in Swedish service. This update was also carried out among the J 29D fleet, and the new, guided missiles considerably improved the aircraft’s capabilities.

Anyway, the J 29D’s small number remained a fundamental problem that prevented bigger success or even export sales, and due to the quick technical advances, the J 29D remained only a stopgap solution. The much more capable Saab 32 Lansen had been under development and its dedicated all-weather fighter variant, the J 32B, had already entered service in 1958, replacing the mixed and outdated lot of radar-equipped fighters in Swedish service.

Nevertheless, the J 29D soldiered on, together with the rest of the J 29F and S 29C fleet, until 1970, even though not in front line duties anymore.

General characteristics:

Crew: 1

Length: 10.80 m (35 ft 4 1/2 in)

Wingspan: 11.0 m (36 ft 1 in)

Height: 3.75 m (12 ft 4 in)

Wing area: 24.15 m² (260.0 ft²)

Empty weight: 4,845 kg (10,680 lb)

Max. takeoff weight: 8,375 kg (18,465 lb)

Powerplant:

1× Svenska Flygmotor RM2B afterburner turbojet, rated at 6,070 lbf (27 kN)

Performance:

Maximum speed: 1,060 km/h (660 mph)

Range: 1,100 km (685 mi)

Service ceiling: 15,500 m (50,850 ft)

Rate of climb: 32.1 m/s (6,320 ft/min)

Armament:

4x 20mm Hispano Mark V autocannon in the lower front fuselage

Typically, a pair of 400-liter (106 US gallon) or 500-liter (132 US gallon) drop tanks was carried on the outer “wet” pylons

Further air-to-air ordnance initially consisted of 75 mm (3 in) air-to-air rockets, from 1963 onwards the J 29D could also carry up to 4x Rb 24 (AIM-9B Sidewinder) IR-guided air-to-air missiles.

Optionally (but never carried in service), the J 29D could also deploy a wide range of bombs and unguided missiles, including 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

The kit and its assembly:

Sweden is a prolific whiffing territory, and the Saab 29 offers some interesting options. The all-weather Tunnan was a real Saab project, and things actually got as far as the aforementioned radome shape test stage. But eventually the project was fully dropped, since Saab had been busy with standard J 29 production and conversions, so that this aircraft never materialized, just as the projected side-by-side trainer Sk 29 of the same era.

However, I recently came across a nice Saab 29 book which also covers some projects – including drawings of the radar-equipped Tunnan that never was. My converted model with the thimble radome and the raked air intake is based on these drawings.

The basic kit is the Heller Saab 29, which I deem superior to the Matchbox Tunnan, with its mix of raised and engraved panel lines and overall rather soft detail (despite the surprisingly nice cockpit). Anyway,, the Heller kit has its flaws, too, e. g. a generally weak material thickness, lack of locator pins or other stabilizing aids and some sinkholes here and there.

The kit was built mostly OOB, with as much lead in the gun tray as possible - and it actually stands on its own three feet/wheels! The only major change is the modified nose section. It sounds simple to graft a radome onto the Tunnan's nose, but the rhinoplasty was challenging. The whole front end had to be renewed, based on the profile drawings and sketches at hand.

The thimble radome is actually a recycled drop tank front end from a Hasegawa F6F Hellcat. The raked, lower aitr intake lip comes from a Matchbox Mystère IVA - but it lost its splitter, was reshaped and had the OOB air intake duct glued into place from behind. Once the intake was glued into its place, a wedge opeing was cut into the area in front of the canopy and the drop tank radome adapted to the gap, a step-by-step approach, since I wanted to have the radome slightly protrude into the airtake, but also keep a staright line in front of the windscreen.

Additional details include new pitots on the wing tips and some additional antennae. The heat shield for the afterburner engine is OOB, as well as the streamlined drop tanks and their pylons. I just added an additional pair of pylons (from an Acedamy MiG-23) to the inner wing, holding a pair of AIM-9Bs.

Painting and markings:

Finding a suitable, yet “different” scheme for the J 29 night fighter was not easy; most J 29 were left in bare metal, some carried dark green upper surfaces and some S 29C wore a paint scheme in olive green and dark blue. I eventually settled for the RAF style paint scheme that had been adopted with the J 30 Mosquito and J 33 Venom night fighters – not spectacular, but different from the Swedish early Sixties norm, and it subtly underlines the J 29D’s role.

The scheme was lent from RAF Venom night fighters (which was used on the Swedish J 33, too), and of the upper surfaces I used RAF tones, too: Humbrol 163 (Dark Green) and 165 (Medium Sea Grey). However, I did not want to use the grey on the lower surfaces, since I found that scheme a bit too uniform and British, so I painted the lower surfaces in NMF, with a waterline at medium height - higher than the camouflaged S 29C’s and lower than the early, camouflaged J 29A fighters (with an experimental all-green upper surface).

The bare metal finish was created with acrylic Aluminum (Revell 99) and Polished and Matt Aluminum Metallizer (Humbrol) added on top, highlighting single panels. Around the engine bay and the exhaust, a base with Iron (Revell 91) was laid down, with Steel Metallizer (Modelmaster) on top.

Under the wing tips, green formation markings (again Humbrol 163) were added, as well as black ID stripes (cut from generic decal sheet material). Other, Swedish adornment, like the roundels, codes or squadron markings, was taken from the OOB sheet, a PrintScale sheet for the J 29 and leftover decals from a Heller J 21.

Interior details were painted according to Swedish standard, thankfully there are many good pictures available. The cockpit interior became grey-green (Revell 67 comes very close to the real thing) with light grey dashboard and side consoles. The landing gear wells medium (Revell 57) grey with some dry-brushed Aluminum, while the wheel discs became grey-green, too.

An interesting result, through relatively little effort: the dog nose changes the look of the tubby J 29 a lot, it looks much sleeker and somewhat German now – but somehow also more retro than the original aircraft? The different paint scheme looks unusual, too, despite being relatively down-to-earth. This will certainly not be my last modified J 29, a two-seat trainer would certainly be another cool and reality based Tunnan whif?

1:72 Saab P29G “Kurviga Tunnan” a.k.a. “Karpen“; 2nd prototype “Röd Urban” (s/n 29488), fitted with experimental 45° wings, Swedish Air Force during high speed trials; Malmslätt, Sweden, summer 1959 (Whif/Matchbox kit conversion) by Dizzyfugu

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