The Light Helicopter Experimental (LHX) program was a 1980s
United States Army
The United States Army (USA) is the land warfare, land military branch, service branch of the United States Armed Forces. It is one of the eight Uniformed services of the United States, U.S. uniformed services, and is designated as the Army o ...
helicopter procurement project to replace the
AH-1 Cobra
The Bell AH-1 Cobra is a single-engined attack helicopter developed and manufactured by the American rotorcraft manufacturer Bell Helicopter. A member of the prolific Huey family, the AH-1 is also referred to as the HueyCobra or Snake.
The AH ...
and
OH-58 Kiowa
The Bell OH-58 Kiowa is a family of single-engine single-rotor military helicopters used for observation, utility, and direct fire support. It was produced by the American manufacturer Bell Helicopter and is closely related to the Model 206A ...
helicopters.
Background
In support of the LHX program, the United States Army started the Advanced Composite Airframe Program (ACAP) to develop an all-composite helicopter fuselage.
[Historic US Army Helicopters](_blank)
. US Army In February 1981, contracts were awarded to Sikorsky (for the
Sikorsky S-75
The Sikorsky S-75 was a proof-of-concept all-composite helicopter. Sikorsky Aircraft used all-composite materials to replace metal to provide greater strength, lighter weight, lower manufacturing costs, and reduce maintenance costs.
Design and ...
) and Bell Helicopter (for the
Bell D-292
The Bell D-292 was an American experimental helicopter developed by Bell Helicopters
Bell Textron Inc. is an American aerospace manufacturer headquartered in Fort Worth, Texas. A subsidiary of Textron, Bell manufactures military rotorcraft ...
).
LHX program
An Army Aviation Mission Area Analysis, completed in 1982, identified deficiencies in current materiel and doctrine that needed to be addressed to meet the requirements of the new Airland Battle Doctrine. The specific material deficiencies were to be resolved through the LHX program.
[A Case History of the US Army RAH-66 Comanche Helicopter](_blank)
/ref>
In 1982, the U.S. Army started the Light Helicopter Experimental (LHX) program to replace the UH-1
The Bell UH-1 Iroquois (nicknamed "Huey") is a utility military helicopter designed and produced by the American aerospace company Bell Helicopter. It is the first member of the prolific Huey family, as well as the first turbine-powered helic ...
, AH-1, OH-6, and OH-58 helicopters. In August 1986, the Defense Science Board review revealed that the Army suffered from stovepiping in a program development sense, and could not think outside the box
Thinking outside the box (also thinking out of the box or thinking beyond the box and, especially in Australia, thinking outside the square) is a metaphor that means to think differently, unconventionally, or from a new perspective. The phrase al ...
. The Army solidified requirements too early without sufficient risk management. A single-crew version was an early requirement, but depended upon successful development of a risky electronic package.
Early concepts included both utility and scout/attack versions, but by 1988, the utility concept was dropped.[Frawley, Gerard. ''The International Directory of Military Aircraft'', p. 50. Aerospace Publications Pty Ltd, 2002. .] A Request for proposals for the new helicopter type was released in June 1988. In October 1988, the Boeing-Sikorsky and Bell-McDonnell Douglas teams received contracts for their designs. The Bell-McDonnell Douglas design featured ordnance carriage within a combined wing/sponson
Sponsons are projections extending from the sides of land vehicles, aircraft or watercraft to provide protection, stability, storage locations, mounting points for weapons or other devices, or equipment housing.
Watercraft
On watercraft, a spon ...
and instead of a tail rotor used a NOTAR
NOTAR ("no tail rotor") is a helicopter system which avoids the use of a tail rotor. It was developed by McDonnell Douglas Helicopter Systems (through their acquisition of Hughes Helicopters). The system uses a fan inside the tail boom to build ...
ducted exhaust system. The Boeing-Sikorsky design carried ordnance within upward swinging gull-wing doors in the sides of the fuselage and featured a fenestron
A Fenestron (sometimes alternatively referred to as a fantail or a "fan-in-fin" arrangementLeishman 2006, p. 321.) is an enclosed helicopter tail rotor that operates like a ducted fan. The term ''Fenestron'' is a trademark of multinational heli ...
tail rotor. The program's name was changed to Light Helicopter (LH) in 1990.[Jackson, Paul, ed. "Boeing Sikorsky RAH-66 Comanche". ''Jane's All the World's Aircraft, 2006-2007''. Jane's Information Group, 2006. ]
(subscription article)
/ref> In April 1991, the Boeing-Sikorsky team was selected as the contest winner and received a contract to build four prototypes.[Eden, Paul, ed. "Boeing/Sikorsky RAH-66 Comanche". ''Encyclopedia of Modern Military Aircraft''. Amber Books, 2004. .]
In March 2004, the Army Chief of Staff terminated the Comanche program. The termination happened for several reasons; among them were unrealistic and unachievable overarching requirements, the rising projected cost of production, changing aviation mission of the Army (refusal to consider the changing threat environment), lack of sufficient funding for other critical aviation needs, the lack of achieving reduced risk of certain key technologies, and chronic groupthink
Groupthink is a psychological phenomenon that occurs within a group of people in which the desire for harmony or conformity in the group results in an irrational or dysfunctional decision-making outcome. Cohesiveness, or the desire for cohesiveness ...
.The Comanche Helicopter Program - A Strategic Policy Failure
- US Army War College
See also
* Bell D-292
The Bell D-292 was an American experimental helicopter developed by Bell Helicopters
Bell Textron Inc. is an American aerospace manufacturer headquartered in Fort Worth, Texas. A subsidiary of Textron, Bell manufactures military rotorcraft ...
* Sikorsky S-75
The Sikorsky S-75 was a proof-of-concept all-composite helicopter. Sikorsky Aircraft used all-composite materials to replace metal to provide greater strength, lighter weight, lower manufacturing costs, and reduce maintenance costs.
Design and ...
* LHX Attack Chopper
References
{{Reflist, 1
External links
Light Helicopter Experimental (LHX)The Comanche Helicopter Program - A Strategic Policy Failure
Military helicopters
Military aircraft procurement programs of the United States