Sunday 29 September 2019

Cobraaaa!!!!



Historical Background
The emergence of the helicopter, specifically of  Bell's UH-1 Iroquois or Huey, made the theory of air cavalry practical. In Vietnam, the Huey fleet carried troops across the country, to fight at the ground and the time of their own choosing, rather than the enemy's. However, these unarmed Hueys were vulnerable to ground fire especially when they are nearing the landing zones. Without support from nearby artillery or other ground troops, the only way to pacify the landing zones was from the air, using an aircraft, preferably another, armed, helicopter that can closely escort the transport choppers and loiter over the battlefield. Originally the Army used UH-1s fitted with machine guns and rocket launchers, but was needed was a dedicated helicopter gunship Bell has been investigating such concept since the 1950s and in 1962 had revealed a mockup of what they called D-255 Iroquois Warrior concept. The D-255 was a purpose-built attack helicopter based on the UH-1B but with a slender fuselage and the two crew sitting in tandem. It was to be armed with a turret-mounted 40mm grenade launcher in the nose, a 20 mm belly-mounted gun pod and stub wings to mount rockets or anti-tank missiles.

The Army was interested and awarded a proof-of-concept contract to Bell in December 1962. Bell modified a regular Bell Model 47 (UH-13 Sioux) into Model 207 Sioux Scout which had the hallmarks of a modern attack helicopter with sleek fuselage, tandem cockpit, chin-mounted turret and stub wings for weapons. Although impressed, the Army decided that the Model 207 was too small, underpowered and generally not suitable for practical use. Instead the Army launched the Advanced Aerial Fire Support System (AAFSS) which resulted in the large and fast Lockheed AH-56 Cheyenne. It proved to be too sophisticated and was eventually cancelled in 1972. Although Model 207 was rejected by the Army, Bell persisted with their idea of a smaller and lighter helicopter gunship. Bell mated the T53 turboshaft engine, the transmission and the rotor system of the UH-1C, adding to the latter a Stability Control Augmentation System with the design philosophy of the Sioux Scout and produced the Model 209.

With the war escalating in Vietnam and the AAFSS programme stuck in technical difficulties and political bickering, the US Army asked Boeing-Vertol, Sikorsky, Kaman, Piasecki and Bell for an interim gunship design. In April 1966, Bell's Model 209 won the evaluation and a first production contract for 110 airframes were signed. Bell added 'Cobra' to the UH-1's nickname of 'Huey' becoming Model 209 HueyCobra - the name adopted by the Army for its production AH-1G. For production some modifications was made, including the adoption of simple landing skids instead of retractable undercarriage, a new wide-blade rotor and plexiglass, instead of armoured glass canopy. The first HueyCobras were delivered in June 1967 and saw extensive service during the Vietnam War, taking over the role of assault helicopter from the 'snake' Huey gunships.

The Cobra has a slim fuselage, designed to present as small a profile as possible against enemy ground fire. Due to the slimmer shape and lighter weight, the Cobra is twice as fast as the Hueys it escorted. The original variants were powered by a single Lycoming T53-L-11 turboshaft engine rated at 1,100 hp allowing it a speed of 277 km/h. The crew seating arrangement, which has since become the virtual standard for attack helicopters, placed the pilot at the rear seat, which is slightly elevated behind the co-pilot/gunner. The gunner also a full set of flight controls. The weapons turret under the nose were originally used to mount two 7.62 mm miniguns or two 40 mm grenade launchers or one of each weapon. Later versions of the Cobra mounts the M197 20 mm three-barrel cannon in the turret. The stub wings can carry up to 1,360 kg of various weapons but usually consist of folding fin aerial rocket tubes, gun pods or, later, anti-tank guided weapons.

Originally not equipped to fire anti-tank guided weapons, the Cobra was fitted with the M65 TOW/Cobra system complete with M65 Telescopic Sight Unit and M73 reflex Sight, creating the AH-1Q variant in 1973. The AH-1S is an upgraded -1Q variant with 1,800 hp Lycoming T53-l-703 turboshaft. The -1S was followed by the -1P with glass cockpit, improved low-altitude performance and composite rotor assembly. The AH-1E introduced the three-barrel M197 cannon while the AH-1F introduced laser rangefinder, infra-red countermeasure equipment, digital flight systems and heads-up display. Prior to 1988, all the S,P,E,Q and F Cobras were simply known as various variants of the AH-1S. Apart from the Vietnam War, US Army Cobras took part during Operation Just Cause in Panama in 1989, Operation Desert Shield / Desert Storm in 1990/1991 and Operation Restore Hope in Somalia in 1993 and Operation Uphold Democracy in Haiti in 1994. 300 Cobras were lost due to enemy action and accidents during the Vietnam War with a further three during Desert Storm. The Cobra was phased out and replaced by the AH-64 Apache in US Army service beginning in 1990 and fully retired from service in 2001. Retired machines were passed to allied nations and also the USDA Forest Service. The Cobra was exported and used by the armed forces of Israel, Japan, Jordan, Turkey and Pakistan.       

The Kit
Hasegawa came out with a 1/72 kit of the single-engine Cobra in 1997 when they released the JGSDF version of the AH-1S. The US version was released in 2000 while the one I use in this build is a 2015 reboxing of the 2000 kit. And, according to online reviews, this is the most accurate version of the -1S (at least for the 1/72 version). The parts are spread among five dark olive drab sprues, one clear sprue and a small decal sheet. The parts are well moulded and have engraved panel lines. Some are marked as 'Not for use' as probably they are only relevant to the JGSDF version. Details are acceptable for 1/72 scale and from casual viewing, it looks like it's going to be a simple, straightforward build. It also includes two crew figures. The decals provide markings for just one helicopter : a snake from the 7th Cavalry, US Army.

Construction
Almost inevitably with flying machine models, even the rotary winged ones, construction started with the cockpit. And as per my usual practice, the relevant parts were painted while on the sprue. There were just two paints needed for the cockpit - flat and gloss black. The parts were then removed from the sprue and the resulting scars were then touched up. The parts were then assembled, the crew fifures however were not used. The provided decals were then used to represent the instrument panels on the cockpit sides. Before the fuselage halves were cemented together, holes were drilled or puttied over where needed and the cockpit sides were painted Black. Afterwards, the completed cockpit plus the bottom of the fuselage (Part A4) were inserted into one of the cockpit halves and the whole fuselage was cemented together. The tail skid was however left off at this time.

Next up were some of the external features. The tail fins were first and some care were needed here to avoid gaps. The stub wings were next. The halves were mated together, sanded and then cemented to the fuselage. The pylons for the FFAR pods were also added at this time although the TOW missile assembly was left off. The last sub-assembly I added to the model at this time was the sight at the nose. In order to ease handling during painting and decalling, the landing skids were left off. Although the tail rotor, the M197 cannon and the exhaust were assembled, they were set aside at his time.


Painting and Decalling
Hasegawa has you paint the model entirely in Olive Drab. However, based on my readings during my AH-64 Apache build, US Army helicopters are painted Helo Drab instead of Olive Drab. For modellers, only Model Master has this particular paint in their range. I'm not going to wait for several more weeks in order for newly-ordered paint to arrive. So decided to use the next best alternative : Tamiya's XF-51 Khaki Drab. While it does not exactly match Helo Drab, looking at photos on the internet shows that Helo Drab can assume shades from OD to Dark Grey but I think XF-51 is just about the shade of the 'original' Helo Drab. The FFAR pods and the TOW tubes however were painted US Olive Drab. The M197 cannon was painted black and then I decided to use my newly acquired AK Interactive weathering pencil 'Gun Metal'. The pencil works as the usual pencil-watercolour combo. The graphite(?) is moistened and then applied over the parts....and voila, metallic-looking parts! The narrow sealing tape however was not painted as I doubt my ability to cleanly mask and paint such a narrow line.

The decals were then applied in the usual manner and was then given the Mr. Mark Softer treatment.

Finishing
Finishing at this stage means permanently attaching the remaining sub-assemblies. I started with the weapons first. By the way, the kit FFAR pods were replaced with the ones from the Italeri weapons kit as the latter has the 'rocket heads' (for what its worth) poking from the tubes, whilst the kit ones are more or less 'empty'. Once the skids were attached, I found that the model was not very stable and usually went tail-heavy. However once the main rotor was put in place, it no longer has that nose-up attitude. The cannon assembly and the canopy howere were quite a tight fit and the cannon nearly broke apart when I try to insert it into its slot. The canopy needed a bit of sanding to get it into place; however the finished still has quite a noticeable gap. The model received a coat of Gunze Flat Coat and the masks were then removed, finishing the build.

Conclusion
Hasegawa's 1/72 Cobra is an easy kit to build and without any real shortcomings. The details are convincing enough especially in 1/72 although those who wants more detail can easily add them.

No comments: