The Boeing/Sikorsky RAH-66 Comanche was an advanced U.S. Army military helicopter intended for the armed reconnaissance role, incorporating stealth technologies. It was also intended to designate targets for the AH-64 Apache.Crawford, Steve. Twenty-First Century Military Helicopters, p. 88. MBI Publishing, 2003. ISBN 0-7603-1504-3. The RAH-66 program was canceled in 2004 before it was fielded.

Design and development

In 1982 the U.S. Army started the Light Helicopter Experimental (LHX) program to replace UH-1, AH-1, OH-6, and OH-58 helicopters. This requirement was changed to a reconnaissance helicopter by 1988.Frawley, Gerard. The International Directory of Military Aircraft, p. 50. Aerospace Publications Pty Ltd, 2002. ISBN 1-875671-55-2.
Request for proposals for the new helicopter type were released in June 1988. In October 1988, the Boeing-Sikorsky and Bell-McDonnell Douglas teams received contracts for their designs. 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, 2004-2005. Jane's Information Group, 2004. ISBN 0710626142. In April 1991, the Boeing-Sikorsky team was selected as the contest winner and received a contract to build four prototypes, Also that month the helicopter was designated "RAH-66 Comanche" by the Army. In 1993, the first prototype began assembly. The following year the number of prototypes was cut to two.Eden, Paul, ed. "Boeing/Sikorsky RAH-66 Comanche". Encyclopedia of Modern Military Aircraft. Amber Books, 2004. ISBN 1904687849.
The U.S. Army's current armed scout helicopter is the OH-58D Kiowa Warrior, but it is an upgraded version of a Vietnam War-era observation helicopter. The Comanche however was specifically tailored to the role of armed scout. It is smaller and lighter than the AH-64 Apache attack helicopter. The RAH-66's fuselage is long and is made of composite material. Its incorporated stealth features to avoid detection, such as retractable weapon stations and main gun, and stealth faceting and radar absorbent materials. The Comanche's noise signature is noticeably smaller than others in its class. The RAH-66 is powered by two LHTEC T800 turboshaft engines.. Boeing Sikorsky, 1998.
The Comanche's very sophisticated detection and navigation systems were intended to allow it to operate at night and in bad weather. Its airframe was designed to fit more easily than the Apache into transport aircraft or onto transport ships, enabling it to be deployed to hot spots quickly. If transport assets were not available, the Comanche's ferry range of would allow it to fly to battlefields overseas on its own.
The first Comanche prototype was rolled out of the Sikorsky Aircraft's helicopter production facility on 25 May 1995. The prototype's maiden flight occurred on 4 January 1996. Flight qualification tests and evaluations were conducted for the two DEM/VAL (Demonstration and Validation Phase) prototypes. Through the early 2000s, the U.S. Army planned to purchase over 1,200 Comanches to fill the scout and light attack roles, with deliveries of operational RAH-66s beginning in 2006.Bolkcom, Christopher. . Congressional Research Service, 2 July 2003.
Flight testing was conducted through 2002 with the two prototypes. The first Commanche prototype (number 94-0327) completed 318 flights over 387 hours before ending its testing career in January 2002. After meeting key criteria, the RAH-66 entered the Engineering and Manufacturing Development (EMD) phase on 1 June 2000. Efforts to reduce empty weight by or 2% to meet target weight were begun later that year. The second prototype (number 95-0001) was in flight testing until May 2001. In 2002 the program was restructured and the number of Comanches to be purchased was cut to 650.
RAH-66 #2 received mission equipment and more powerful T800-LHT-801 engines and it continued flight testing, including testing of night vision and weapon systems in 2002 and 2003. EMD was planned to last six years with five Comanches built then for testing. Production on the RAH-66 #3 third (first EMD RAH-66) began in 2003. Following those, eight RAH-66s were to be built for operational testing.Jackson, Paul, ed. "Boeing Sikorsky RAH-66 Comanche". Jane's All the World's Aircraft, 2004-2005. Jane's Information Group, 2004. ISBN 0710626142.

Cancellation

On 23 February 2004, the U.S. Army announced their decision to cancel the Comanche helicopter program in view of the need to provide funds to renovate the existing helicopter fleet of aging attack, utility, and reconnaissance aircraft. Also a factor was the growing popularity in the military of using unmanned aerial vehicles (UAVs) for reconnaissance purposes – in addition to tests, UAVs had proven their worth in Afghanistan and Iraq. About US$6.9 billion had already been invested in the Comanche program at the time of its termination. An additional US$450–680 million was required in contract termination fees to main program partners Sikorsky and Boeing Integrated Defense Systems.

Technology developed for the Comanche will be integrated into the Apache and other U.S. military helicopter developments. The Army was developing the Bell ARH-70 to replace the OH-58D in place of the RAH-66, but after cost overruns, the ARH-70 was canceled in October 2008.

Currently the prototype airframe 95-0001 "The DUKE" is located at the US Army Aviation Museum in Fort Rucker, Alabama and 94-0327 was to arrive at the museum in 2008.

Specifications (RAH-66A)

A cutaway drawing of a RAH-66 Comanche

See also