1:72 Bell AH-1-4BW 'SuperCobra' Phase III; ‘98+11 (s/n 161 022)’, Westdeutsche Bundesluftwaffe during evaluation trials at Wehrtechnische Dienststelle (WTD) 61, Manching/Bavaria, 1990 (Whif/Italeri kit conversion)

+++ 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 Bell AH-1 SuperCobra is a twin-engined attack helicopter that was developed on behalf of, and primarily operated by, the United States Marine Corps (USMC). The twin Cobra family, itself part of the larger Huey family, includes the AH-1J SeaCobra, the AH-1T Improved SeaCobra, and the AH-1W SuperCobra. The Super Cobra was derived from the single-engine AH-1 Cobra, which had been developed during the mid-1960s as an interim gunship for the U.S. Army. The USMC had quickly taken an interest in the type but sought a twin-engine arrangement for greater operational safety at sea, along with more capable armaments. While initially opposed by the Department of Defense, who were keen to promote commonality across the services, in May 1968, an order for an initial 49 twin-engine AH-1J SeaCobras was issued to Bell. The type entered service during the final months of the US's involvement in the Vietnam War, seeing limited action in the theatre as a result.

 

The USMC promptly sought greater payload capacity than that provided by the original Sea Cobra; thus the AH-1T, equipped with the dynamic systems of the Model 309 and a lengthened fuselage, was produced by Bell during the 1970s. In the following decade, in response to the denial of funding to procure the Boeing AH-64 Apache attack helicopter, the USMC opted to procure a more capable variant of the AH-1T; equipped with revised fire control systems compatible with new munitions, such as the AGM-114 Hellfire anti-tank missile, the new model, designated AH-1W, commenced delivery in 1986.

 

In the early 1980s, the Marine Corps sought a new navalized helicopter. Accordingly, it evaluated the Boeing AH-64 Apache attack helicopter as first choice over a two-week period in September 1981, which included shipboard operation tests. Furthermore, various concepts were studied at this time. However, the service's request for funding to purchase the AH-64 was denied by Congress that same year. As an alternative option, the Marines procured a more powerful version of the AH-1T. Other changes included modified fire control systems to carry and fire AIM-9 Sidewinder and AGM-114 Hellfire missiles. The new version, which was funded by Congress, received the AH-1W designation. During March 1986, deliveries of the AH-1W SuperCobra commenced, eventually totaling 179 new-built helicopters along with the upgrading of 43 existing AH-1Ts.

 

This development also fell into the period when Great Britain was looking for a potential attack helicopter for the British Army, and Western Germany was - together with France - about to mutually develop a new attack helicopter that would in Germany replace the PAH-1, the light Bo 105 helicopter armed with six HOT anti-tank missiles. In 1984, the French and West German governments had issued a requirement for an advanced antitank helicopter, with one variant desired by the French dedicated to the escort and antihelicopter role. As originally planned, both countries would procure a total of 427 helicopters called “Tiger”. The West Germans planned on acquiring 212 models of the anti-tank variant named PAH-2 (Panzerabwehrhubschrauber or "Anti-tank helicopter"), with deliveries starting at the end of 1992. The French wanted 75 HAPs (Hélicoptère d'Appui Protection or "Support and Escort Helicopter") and 140 HACs (Hélicoptère Anti Char or "Anti-Tank Helicopter"), with deliveries starting at the end of 1991 and 1995, respectively. In the meantime, the USA also offered both the AH-1 as well as the more modern AH-64 as alternatives.

 

Development of the Tiger started during the Cold War, and it was initially intended as a pure anti-tank helicopter platform to be used against a Soviet ground invasion of Western Europe. A joint venture, consisting of Aérospatiale and MBB, was subsequently chosen as the preferred supplier, but in 1986 the development program was already canceled again due to spiraling costs: it had been officially calculated that supplying the German forces with an equivalent number of US-produced McDonnell Douglas AH-64 Apache attack helicopters would have been a considerably cheaper alternative to proceeding with the Tiger’s development, which became a more and more complex project because the helicopter would have to be able to fulfill more roles, and the duty profiles of Germany and France became significantly different. According to statements by the French Defence Minister André Giraud in April 1986, the collaborative effort had become more expensive than an individual national program and was also forecast to take longer to complete.

 

This opened the door for American proposals even wider, and beyond the state-of-the-art AH-64 Bell proposed a further upgraded two-engine AH-1W. Bell had been working as a private initiative with both the AH-1T+ demonstrator and the AH-1W prototype, and developed a new experimental hingeless rotor system with four composite blades, designed to withstand up to 23 mm rounds and thus greatly improving battlefield survivability. This new main rotor was manually foldable, reduced vibrations and allowed the engine power to be increased, thus greatly improving the SuperCobra’s performance and load capabilities. The twin engine’s power had until then been restricted, but in the AH-1-4BW the power was liberated to full 1,800 shp (1,342 kW), with a reinforced gearbox that could even cope with 2.400 shp. Top speed climbed by 23 mph/37 km/h, rate of climb improved, and the load capability was raised by 1.000 lb (450 kg). The AH-1-4BW was now able to fly a full looping, something the AH-1 had not been able to do before. However, empty weight of this demonstrator helicopter climbed to 12,189 lb (5,534 kg) and the maximum TOW to 18,492 lb (8.391 kg).

 

Other changes included a different position for the stabilizers further aft, closer to the tail rotor, which furthermore received small end plates to improve directional stability. The modified AH-1W prototype was aptly re-designated “AH-1-4BW” (4BW standing for “4-blade whiskey”), and there were plans to upgrade the type even further with a fully digitalized cockpit to meet contemporary requirements, e.g. for the British Army.

 

The West-German Bundesluftwaffe’s interest in the “outdated” AH-1 was initially only lukewarm, but when Bell offered to lend the AH-1-4BW prototype for evaluations and as a development mule for the eventual integration of the European HOT missile and indigenous sensors and avionics, a mutual agreement was signed in late 1987 to have the AH-1-4BW tested by the Luftwaffe in the environment where the type would be operated.

The AH-1-4BW prototype (s/n 166 022) was delivered to Manching in Southern Germany in summer 1988 on board of a C-5 Galaxy. It was operated by the Luftwaffe’s Wehrtechnische Dienststelle (WTD, Technical and Airworthiness Center for Aircraft) 61 for two years and successfully made several tests. This program was divided into three “Phases”. “Phase I” included focused on flight characteristics, tactical operations, and mock air-to-air combat against Luftwaffe CH-53s which acted as Mi-24 aggressors. Upon program start the AH-1-4BW received German markings, the registration 98+11, and a new, subdued paint scheme in Luftwaffe colors instead of the original USMC scheme in an overall medium green.

 

In “Phase I” the AH-1-4BW retained its American weapon systems, as the flight testing did not involve weapon deployment or integration. Instead, dummies or target designators were carried. After these initial tests that lasted almost a year Bell agreed to let the WTD 61 modify the AH-1-4BW further with European avionics to deploy the HOT 3 anti-tank missile, which would be the helicopter’s primal weapon in the German Heeresflieger’s service, since Germany did at that time neither use the similar American TOW nor the more sophisticated AGM-114 Hellfire, even though the German PARS 3 LR missile (also known as TRIGAT-LR: Third Generation AntiTank, Long Range) was already under development since 1988. This upgrade and test program section received the designation “Phase II”. Outwardly, the newly modified AH-1 was recognizable through a different sensor turret in the nose and a modified HOT missile sight for the gunner in the front seat.

 

In late 1989 the helicopter underwent another modification by WTD 61, which was to test equipment already intended for the PAH-2. Under the trials’ final “Phase III” the AH-1-4BW received a globular fairing on a mast on top of the main rotor, to test the tactical value of observing, identifying, and selecting targets while the helicopter would remain in cover. This sensor mast combined a panoramic IR camera with a targeting sight for anti-tank missiles and the gun turret, and it functionally replaced the standard chin sensor turret (which was brought back to AH-1W standard). Another novel feature was a streamlined, sugar scope-shaped exhaust diffusor with two chambers which guided hot gases upwards into the main rotor’s downwash, as an alternative to the original diffusors which only mixed cold ambient air with the hot efflux. It turned out to be very effective and was subsequently adapted for the Tiger. Other changes included a new hingeless three-blade tail rotor that was supposed to reduce operational noise and frequency issues with the new 4-blade main rotor, and the endplate stabilizers were enlarged to compensate for the huge “eyeball” on top of the main rotor which significantly changed the AH-1’s flight characteristics, especially at high speed.

 

Further tests of the Phase III SuperCobra lasted until summer 1990 and provided both Bell as well as the Luftwaffe with valuable benchmark data for further weapon system developments. When the lease contract ended in 1991, the AH-1-4BW was sent back to the United States. In the meantime, though, the political situation had changed dramatically. The USSR had ceased to exist, so that the Cold War threat especially in Europe had ended almost overnight after the Aérospatiale/MBB joint venture, now officially called Eurocopter, had signed an agreement in 1989 which financially secured the majority of the Tiger’s pending development through to serial production, including arrangements for two assembly lines to be built at Aerospatiale's Marignane plant and MBB's Donauwörth facility. This eventually saved the Tiger and in 1991 it had become clear that no American attack helicopter would be bought by either Germany or France. Great Britain as another potential European customer also declined the AH-1 and eventually procured the more modern AH-64 in the form of the license-built AgustaWestland Apache.

 

In 1992, the Eurocopter Group was officially established, and the Tiger moved closer to the hardware stage; this led to considerable consolidation of the aerospace industry and the Tiger project itself. A major agreement was struck in December 1996 between France and Germany that cemented the Tiger's prospects and committed the development of supporting elements, such as a series of new generation missile designs for use by the new helicopter. National political issues continued to affect the prospects of the Tiger, however. A proposed sale of up to 145 Tigers to Turkey proved a source of controversy; Turkey selected the Tiger as the preferred option, but conflicting attitudes between Eurocopter, France and Germany regarding military exports led to Turkey withdrawing its interest. Eventually, Turkey procured AH-1s and started an indigenous attack helicopter program.

 

However, the AH-1-4BW’s development and its vigorous testing in Germany were not in vain: Lacking a USMC contract, Bell developed this new design into the AH-1Z with its own funds during the 1990s and 2000s. By 1996, the Marines were again prevented from ordering the AH-64: developing a marine version of the Apache would have been expensive and it was likely that the Marine Corps would be its only customer. Instead, the service signed a contract for the upgrading of AH-1Ws into AH-1Zs, which incorporated many elements from the AH-1-4BW.

 

 

General characteristics:

Crew: Two (pilot, co-pilot/gunner)

Length: 58 ft 0 in (17.68 m) overall

45 ft 7 in (14 m) for fuselage only

Width: 10 ft 9 in (3.28 m) for stub wings only

Height: 13 ft 9 in (4.19 m)

13 ft 9 in (4.19 m) incl. Phase III sensor mast

Main rotor diameter: 42 ft 8 in (13.00 m)

Airfoil: blade root: DFVLR DM-H3; blade tip: DFVLR DM-H4

Main rotor area: 1,428.9 sq ft (132.75 m2)

Empty weight: 12,189 lb (5,534 kg)

Max. take-off weight: 18,492 lb (8.391 kg)

 

Powerplant:

2× General Electric T700-401 turboshaft engine, with 1,800 shp (1,342 kW)

 

Performance:

Maximum speed: 190 kn (220 mph, 350 km/h)

Never exceed speed: 190 kn (220 mph, 350 km/h)

Range: 317 nmi (365 mi, 587 km)

Service ceiling: 12,200 ft (3,700 m)

Rate of climb: 1,620 ft/min (8.2 m/s)

 

Armament:

1× 20 mm (0.787 in) M197 3-barreled Gatling cannon

in the A/A49E-7 chin turret (750 rounds ammo capacity)

4× hardpoints under the stub wings for a wide range of weapons, including…

- 20 mm (0.787 in) autocannon pods

- Twenty-two round pods with 68 mm (2.68 in) SNEB unguided rockets,

- Nineteen or seven round pods with 2.75” (70 mm) Hydra 70 or APKWS II rockets,

- 5” (127 mm) Zuni rockets – 8 rockets in two 4-round LAU-10D/A launchers

- Up to 8 TOW missiles in two 4-round XM65 missile launchers, on outboard hardpoints, or

up to 8 HOT3

up to 8 AGM-114 Hellfire missiles in 4-round M272 missile launchers, on outboard hardpoint,

- Up to 2 AIM-9 Sidewinder anti-aircraft missiles, launch rails above each outboard hardpoint or

up to 2 Air-to-Air Stinger (ATAS) air-to-air missiles in single launch tubes

 

 

The kit and its assembly:

This what-if model was inspired by the real attempts of Bell to sell a twin-engine Cobra variant to Germany as a replacement for the light PAH-1/Bo 105 helicopter, while plans were made to build an indigenous successor together with France which eventually became the PAH-2/Tiger. These proposals fell well into the time frame of the (also) real AH-14BW project, and I imagined that this specific helicopter had been lent to the Luftwaffe for evaluation?

 

The basis is the Italeri 1:72 AH-1W kit, a solid basis which requires some work, though. And because I had the remains of a French Tigre at hand (which gave its cockpit for my recent JASDF A-2 build) I decided to use some of the leftover parts for something that borders a kitbashing. This includes the 4-blade main and 3-blade tail rotor, and I integrated the Tiger’s scoop-shaped exhaust diffusor behind the main rotor – a tricky task that require a lot of PSR, but the result looks very natural, if not elegant? The Tiger’s end plate stabilizers were used, too, mounted to the AH-1’s trim stabilizers that were mounted further back, as on the real AH-1-4BW.

 

To change the look even further I decided to add a sensor pod on top of the main rotor, and this required a totally new mechanical solution to hold the latter. Eventually I integrated a sleeve for a fixed metal axis which also holds the sensor ball (from a MisterCraft Westland Lynx – a bit oversized, but suitable for a prototype), and the PAH-2 rotor received an arrangement of levers that hold it in place and still allow it to spin.

 

The ordnance was also taken from the Italeri Tigre, with HOT quadruple launchers for the outer weapon stations, the inner hardpoints were left empty and I also did not mount the American chaff/flare dispensers on top of the stub wings.

 

 

Painting and markings:

The Luftwaffe did a LOT of interesting camouflage experiments in the early Eighties, adopting several standardized schemes for aircraft, but the Heeresflieger were less enthusiastic and retained the overall Gelboliv (RAL 6014) scheme before a three-color camouflage, consisting of two green tones and a dirty black was gradually introduced – even though apparently not in a uniform fashion, because there were variations for the darker shade of green (retaining RAL 6014 or using FS 34079, as on the Luftwaffe Norm ’83 scheme that was applied to Tornado IDSs, RF-4Es, some Starfighters and to the Transall fleet).

 

My fictional AH-1-4BW would fall into that transitional phase and I decided to give the helicopter an experimental scheme, which was used/tested on early Tornado IDS, consisting of RAL 7021 (Teerschwarz), RAL 7012 (Basaltgrau) and RAL 6014 (Gelboliv) – on aircraft with undersides in RAL 7000 (Silbergrau), but on a helicopter rather as a wraparound scheme. However, inspired by Luftwaffe F-4Fs with a modified Norm ‘72 splinter scheme that added a simple light grey fin to break up the aircrafts’ profile in a side view, I used RAL 7030 (Steingrau) on the tail tip to achieve the same effect, and the light grey was also used, together with Basaltgrau und Gelboliv mottles on the sensor ball – looks a bit like WWII Luftwaffe style, but appeared plausible for the system’s tactical use from behind some ground cover. The cockpit interior became very dark grey, just like the rotor blades, which were adorned with orange warning markings at the tips – seen on some Luftwaffe helicopters instead of classic yellow or red-white-red bands.

 

The decals were puzzled together from various sources. National markings came from generic Luftwaffe sheets from TL Modellbau, the light blue WTD 61 emblems behind the cockpit were taken from a Peddinghaus decal sheet with early Luftwaffe unit markings. The dayglo panels were created with generic decal material (TL Modellbau, too) and stencils came mostly from a Fujimi AH-1 sheet, procuring German or even multi-language material appeared too tedious and costly.

The photo calibration markings on nose and fins were improvised from black and white decal sheet material, punched out, cut into quarters, and then applied as circles. Adds an experimental touch to the Cobra!

 

The kit received a light black ink washing and some post-panel-shading, esp. to brighten up the grey and increase the contrast between the camouflage tones, which appeared even more murky after the dayglow stripes had been added. Finally, the Cobra received an overall coat wit matt acrylic varnish, position lights were added/painted, and the sensor ball received sights made from yellow chrome PET foil, simply punched out and fixed into place with some Humbrol Clearfix.

 

 

This one took a while to materialize and was more work than one might expect at first glance. But it looks quite cool, esp. the PAH-2/Tiger’s exhaust fairing fits very well into the Cobra’s lines and adds an elegant touch to the helicopter. The “Eye ball” is a bit large, yes, but IMHO acceptable for a prototype or test vehicle. And the livery certainly conveys a German touch.

Done