- Yes, both prototypes
- Yes, just the single-engine (2,000 hp) prototype
- Yes, just the twin-engine (1,800 hp) prototype
- No
Twin engine variant of the Bell 309 KingCobra in flight (source- Wikimedia Commons)
In the spirit of Sikorsky’s choice to mix up their two Blackhawks, Bell also confused their new helicopter with their World War II P-63 fighter. ;)
The Bell Model 309 KingCobra was a prototype attack helicopter developed by Bell Helicopter in the 1970s. Powered by an improved engine and mounting advanced avionics and TOW missiles, the KingCobra would’ve been a worthy successor to the Cobra if it was not scrapped alongside its chief competitors, the Lockheed AH-56 Cheyenne and the Sikorsky S-67 Blackhawk. Nevertheless, the systems tested on it would eventually enter service on the AH-1S and the AH-1T.
While the AH-1T Improved SeaCobra, being a production vehicle, would be better suited for the tech tree, the KingCobra could serve as a gap-filler at an even lower BR due to the lack of countermeasures. Since there were two prototypes, they could also be introduced in different ways (e.g. one as tech tree/squadron and the other as premium/event).
History and design
The KingCobra’s history traces back, once again, to the Lockheed AH-56. As the Cheyenne’s development faltered, Bell decided to seize its chance. Although they lost out against Lockheed during the initial Advanced Aerial Fire Support System (AAFSS) competition, Bell hoped to get back into the game with a privately funded design. On 10 September 1971, the Model 309 took to the skies.
The KingCobra was largely based on the existing AH-1 Cobra’s design, a lot more conservative than the AH-56 and S-67 it was to compete against. However, Bell did strengthen the airframe and lengthen the tail boom. Two different engines were installed on the two prototypes. The first mounted a P & W Canada T-400-CP-400 Twin-Pac, the same engine as the AH-1J but with an improved transmission that allowed the full 1,800 hp to be delivered. The second mounted the new Lycoming T55-L-7C with a maximum output of 2,850 hp but downrated to 2,000 hp due to transmission limitations. A new main rotor was also installed.
In anticipation of increased anti-armour missions in Europe, the KingCobra could carry 8 TOW missiles. It also mounted a new sight system, adapted from the one used on the AH-56, providing night vision and thermal imaging capability. The pilot also had a separate night vision sight to aid with flying while the gunner searched for targets. Both crew members had helmet-mounted sights for finding and designating targets. It could also carry the 2.75-inch FFAR in 7- or 19-tube pods. The turret autocannon was the same 20 mm M197, but it was fed by a larger ammunition drum adapted from that of the F-111 Aardvark, which is why there’s a noticeable bulge underneath the fuselage. Unfortunately, no sources speak of the KingCobra carrying any countermeasures, nor any RWR or IR jammer equipment (although Verier mentions Itek as a contractor for the “Radar Warning System”), possibly due to its prototype status. There were also plans to install a larger “wet” wing with a wingspan of 13 feet on the KingCobra, which would increase internal fuel capacity by 500 lbs and allow for more ordinance options, including the AN/ALQ-87 jamming pod and air-to-air missiles. This wing was only installed on the KingCobra in mockup form, so its statistics are not considered in this post.
In the Spring of 1972, the Model 309 was evaluated alongside the AH-56 and the S-67. Eventually, the Army determined that all three helicopters would not satisfy their requirements and rejected them all (in the case of the Cheyenne, the final cancellation of the development project). The Advanced Attack Helicopter program was initiated later that year and cumulated in the Hughes AH-64 Apache. However, the spirit of the Model 309 lives on in the later twin-engine Cobra variants used by the Marines. Many systems tested on the KingCobra were used on the AH-1T Improved SeaCobra, which in turn led to the later AH-1W SuperCobra and AH-1Z Viper.
Specifications
Crew: 2
Physical characteristics and flight performance:
Empty weight: 4,048 kg
MTOW: 6,804 kg
Never exceed speed: 370 km/h
Engine:
- First prototype: P & W Canada T-400-CP-400 Twin-Pac, 1,800 hp
- Second prototype: Lycoming T55-L-7C, 2,000 hp
Avionics and armament:
Avionics:
- Stabilized multisensor sight:
- 3x and 12x day optics
- 2x and 6x night optics
- NVD, FLIR (thermals)
- Laser rangefinder
- Pilot low light level television sensor (NVD)
Armament:
- 20 mm M197 autocannon
- 8x TOW missiles on outer pylons (Peoples claims a 16 TOW loadout, but closer examination suggests that he was referring to the loadout of the planned 13-foot wing)
- 4x FFAR launchers, both 7 and 19 tube variants, all pylons
More pictures
KingCobra carrying TOW missiles and FFAR rockets (source- Bell, via Secret Projects)
Mockup of the 13-foot wing (source- Bell, via Verier)
Stabilized multisensor sight on the KingCobra (source- Bell, via Verier)
Sources
- “Bell AH-1 Cobra” by Mike Verier
- “Huey Cobra Gunships” by Chris Bishop
- “Bell AH-1 Cobra Variants” by Kenneth Peoples
- “ATTACK HELICOPTER EVALUATION, MODEL 309 KING COBRA HELIOCOPTER (AD0771151)” by Paul G. Stringer, et al.
- AN ABRIDGED HISTORY OF THE ARMY ATTACK HELICOPTER PROGRAM (AD1121533) (n.b. while the file exists on DTIC, it is stamped with “NOT RELEASABLE TO FOREIGN NATIONALS”; to play it safe, I am not linking it on the forum)