Boeing / Sikorsky RAH-66 Comanche

Reconnaissance / Light Attack Helicopter

United States | 2004

"The Boeing-Sikorsky joint-venture RAH-66 Comanche light attack helicopter was to become the first stealth-centric combat helicopter in the world - that is until the project was terminated in 2004."

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Power & Performance
Those special qualities that separate one aircraft design from another. Performance specifications presented assume optimal operating conditions for the Boeing / Sikorsky RAH-66 Comanche Reconnaissance / Light Attack Helicopter.

2 x LHTEC T800-LHT-801 turboshaft engines developing 1,563 horsepower each while driving a five-blade main rotor with an eight-blade "fan-in-fin" shrouded tail rotor.
Propulsion

201 mph
324 kph | 175 kts
Max Speed

14,980 ft
4,566 m | 3 miles
Service Ceiling

1,382 miles
2,224 km | 1,201 nm
Operational Range

895 ft/min
273 m/min
Rate-of-Climb

Structure
The nose-to-tail, wingtip-to-wingtip physical qualities of the Boeing / Sikorsky RAH-66 Comanche Reconnaissance / Light Attack Helicopter.

2
(MANNED)
Crew

43.3 ft
13.20 m
O/A Length

39.0 ft
(11.90 m)
O/A Width

11.1 ft
(3.37 m)
O/A Height

9,304 lb
(4,220 kg)
Empty Weight

17,417 lb
(7,900 kg)
MTOW

Armament
Available supported armament and special-mission equipment featured in the design of the Boeing / Sikorsky RAH-66 Comanche Reconnaissance / Light Attack Helicopter provided across 4 (2 x internal bays; 4 hardpoints along optional wing stubs) hardpoints.

STANDARD:
1 x 20mm XM301 three-barrel cannon in chin turret.

OPTIONAL (INTERNAL BAYS):
6 x Hellfire anti-tank missiles OR 6 x Stinger air-to-air missiles OR 24 x Hydra 70 2.75" air-to-surface rockets.

OPTIONAL (STUB WINGS):
8 x Hellfire anti-tank missiles OR 16 x Stinger air-to-air missiles OR 56 x Hydra 70 2.75" air-to-surface rockets.

X X X

X

Hardpoints Key:

Centerline

Wingroot(L)

Wingroot(R)

Wing

Wingtip

Internal

Not Used

Variants
Notable series variants as part of the Boeing / Sikorsky RAH-66 Comanche family line.

RAH-66 "Comanche" - Base Series Designation

YRAH-66 - Prototype Model Designation; two constructed.

Authored By: Staff Writer | Last Edited: 04/06/2021 | Content ©www.MilitaryFactory.com | The following text is exclusive to this site; No A.I. was used in the generation of this content.

At one point, the Sikorsky RAH-66 Comanche was set to become the future of U.S. Army rotary-wing aviation. It was a stealth-based light attack helicopter set to replace an aging stock of Bell UH-1 "Huey" gunships, Bell AH-1 "Cobra" light attack helicopters, Hughes OH-6 "Cayuse" light observation and attack helicopters, and Bell OH-58 "Kiowa" light helicopters. The RAH-66 was the world's first purpose-built stealth attack helicopter complete with fully-powered internal bays housing anti-armor and anti-air missiles and promoted heavy use of stealth materials to help conceal its approach from enemy radar. Had it been serially produced, the RAH-66 would have been the world's most advanced combat helicopter in service with any army anywhere in the world. First flight came on January 4th, 1996.

Origins of the RAH-66 began with the LHX program (Light Helicopter Experimental) of 1982, the design proposal forwarded by a joint Boeing-Sikorsky. The Request for Proposal (RFP) was not enacted until 1988 to which, by now, the U.S. Army requirement had been evolved along the lines of a light reconnaissance-minded attack helicopter. In 1990, the program was given a new name as the Light Helicopter (LH) program and the following year saw the Boeing-Sikorsky submission officially selected as the winner of the program with the U.S. Army seeking four flyable prototypes (YRAH-66) in this early stage. By this time, the product was handed the official designation of "RAH-66" with the name of "Comanche".

Construction on the first airframe commenced in 1993 though the U.S. Army order now contracted for just two prototypes. The aircraft was unveiled in May of 1995 and delivered to Florida for the flight testing phase - the first flight delayed by one year already. First flight by the initial prototype was carried out in 1996 with a second prototype not to join the flight testing phase until later in the decade - recording its first flight on March 30th, 1999.

The compact design adopted a small profile and sharp lines seen previously in the multi-faceted Lockheed F-117 "Nighthawk" during a time when angled panels were the norm for stealth-centric aircraft (since abandoned in more modern stealth designs such as the Lockheed F-22 "Raptor" air superiority fighter). The RAH-66 was given a large five-blade composite main rotor system with a tail rotor housed in a shroud, similar in concept to the French "Fenestron" approach. Internal weapons bays were intended from the beginning as was a retractable powered, wheeled undercarriage. Optional stub wings allowed the helicopter more tactical flexibility when using varied ordnance options though at the cost of a larger radar signature. Standard, fixed armament was a powered 20mm three-barrel General Electric autocannon in a French GIAT turret. The crew of two - pilot and weapons specialist - sat in stepped tandem with good visibility over the surrounding terrain. The RAH-66 was given state-of-the-art flight control systems that included helmet-mounted displays, side-stick cyclic controlling, 3D moving map displays, and Fly-By-Wire (FBW) with triple redundancy feature. Additional components included Forward-Looking Infrared (FLIR) and an onboard self-laser designator for precision munitions. The Hughes Apache Longbow's millimeter wave radar was also standard equipment.

Power came from 2 x LHTEC T800-LHT-801 series turboshaft engines developing 1,563 horsepower each and driving the five-bladed main rotor with an eight-bladed fan-in-fin tail rotor unit. Maximum speed was 200 miles per hour with a range out to 1,382 miles and service ceiling of 15,000 feet. Rate-of-climb was 895 feet per minute.

On the hypothetical battlefield, the RAH-66 system would have supported allied forces by engaging enemy armor at range. The helicopter was granted the scan and track capabilities of the Apache Longbow with the nimbleness of the Bell OH-58 Kiowa series. Weapons support included the Hellfire anti-tank missile, Stinger air-to-air missile as well as Hydra 2.75" rocket pods. The optional wingstubs nearly doubled the ordnance-carrying totals when fixed.

Despite all this, the Comanche product never came to fruition as the entire project was cancelled by the United States Army in the Spring of 2004, mostly due to budgetary cutbacks. It proved more fiscally responsible to simply modernized an aged stock than to procure an expensive, technologically-laden attack system in the numbers required.

The two prototypes have survived the test of time, residing at the United States Army Aviation Museum at Fort Rucker, Alabama.

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Operators
Global customers who have evaluated and/or operated the Boeing / Sikorsky RAH-66 Comanche. Nations are displayed by flag, each linked to their respective national aircraft listing.

Total Production: 2 Units
Contractor(s): Boeing Helicopters / Sikorsky Aircraft Corporation - USA