RAH-66 COMANCHE ARMAMENT SUBSYSTEMS

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RAH-66 COMANCHE ARMED RECONNAISSANCE HELICOPTER (Prototype)

The Boeing-Sikorsky RAH-66 Comanche is the Army's next generation armed reconnaissance helicopter. It also is the first helicopter developed specifically for this role. The Comanche will provide Army Aviation the opportunity to move into the 21st century with a weapon system of unsurpassed warfighting capabilities crucial to the Army's future strategic vision.

The first Boeing-Sikorsky RAH-66 Comanche prototype was rolled-out at Sikorsky Aircraft, Stratford, Connecticut, May 25, 1995. The prototype's first flight was made on 4 Jan 96. The second prototype is scheduled to fly in late March 1999. Six early operational capability aircraft are scheduled to be delivered 2002 to participate in an Army field exercise in 2002-2003, or possibly later in "Corps 04". The Comanche is powered by two Light Helicopter Turbine Engine Co. (LHTEC) T800-801 engines. Its advanced engines will be enable it to maintain sufficient speed to keep up with the more powerful AH-64 series Apache. The Comanche has a crusing speed of 161 knots (185 mph) and a dash speed of 172 knots (198 mph).
Roll-out of the Boeing-Sikorsky RAH-66 Comanche prototype, May 25, 1995

The RAH-66 Comanche helicopter's primary role will be to seekout enemy forces and designate targets for the Army's AH-64 Series Apache Attack helicopter at night, in adverse weather, and in battlefield obscurants, using advanced infrared sensors. The helmet has FLIR images and overlaid symbology that can be used as a headup display in nap-of-the-earth (NOE) flight.

The aircraft has been designed to emit a low-radar signature (stealth features). The Comanche will perform the attack mission itself for the Army's light divisions. The RAH-66 will be used as a scout and attack helicopter to include an air-to-ground and air-to-air combat capability. The Comanche is slated to replace the AH-1 Series Cobra light attack helicopter, the OH-6A Cayuse, and the OH-58A/OH-58C Kiowa light observation helicopters.

The Comanche mission equipment package consists of a turret-mounted cannon, night-vision pilotage system, helmet-mounted display, electro-optical target acquisition and designation system, aided target recognition, and integrated communication/navigation/identification avionics system. Targeting includes a second generation forward-looking infrared (FLIR) sensor, a low-light-level television, a laser range finder and designator, and the Apache Longbow millimeter wave radar system. Digital sensors, computers and software will enable the aircraft to track and recognize advesarys long before they are aware of the Comanche's presence, a key advantage in both the reconnaissance and attack roles.

Aided target detection and classification software will automatically scan the battlefield, identifying and prioritizing targets. The target acquisition and communications system will allow burst transmissions of data to other aircraft and command and control systems. Digital communications links will enable the crew unparalleled situational awareness, making the Comanche an integral component of the digital battlefield.

The armament subsystems consist of the XM301 20mm cannon, and up to 14 Hellfire anti-tank missiles, 28 Air-to-Air Stinger (ATAS) anti-aircraft missiles, or 56 2.75 inch Hydra 70 air-to-ground rockets carried internally and externally. Up to four Hellfire and two Air-to-Air Stinger (ATAS) missiles can be stowed in fully-retractable weapons bays and the gun can be rotated to a stowed position when not in use. This design feature reduces both drag and radar signature.
Hellfire missile system (Copyright Mike Vines, 1998, Aviation Week OnLine)

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Ammunition loading is provided through the swing-away nose and permits access to the feed chute. Loading can be accomplished from any partial load capacity, can occur with the rotors turning, and will not interfere with simultaneous refueling. Three soldiers will be able to refuel and rearm the Comanche under wartime conditions in 15 minutes. A rotary reel ammunition storage system with a capacity of 500 rounds is located below the aft crewman and between the keel beams. Linked ammunition is stored on the reel in a helical path.

Adjacent rows of linked ammunition on the reel are separated by a light-weight helical divider. The divider provides for constant spacing of the rounds as they are stored in the reel. The rotary reel is driven by an electric boost system responsive to gun demand. The linked ammunition is fed to the gun through a flexible chute leading from the reel to the gun. The chute permits ammunition feeding while allowing gun motion in azimuth and elevation. Automatic round counting is accomplished through the MIL-STD-1553B databus for display to the pilot and an external counter is provided for use by maintenance personnel.

The turreted gun system is driven by a 270 Vdc motor and gearbox, mounted as an integral unit to the gun. This motor accelerates the gun to the full firing rates of 750 or 1500 SPM (shots per minute) within 0.25 seconds.

Mission management, status, and control information is provided over the MIL-STD-1553B databus between the mission equipment packages and the Turreted Gun System. The Comanche will have enhanced maintainability through it's modular electronics architecture and built-in diagnostics.

RAH-66 COMANCHE CAPABILITIES

Sensors and avionics. In the reconnaissance role, the Comanche will be equipped with a new generation of passive sensors and a fully integrated suite of displays and communications. Advance infrared (IR) sensors will have twice the range of OH-58D Kiowa Warrior and AH-64 Apache sensors. The Comanche will be equipped with the Apache Longbow fire control radar and the Helmet Integrated Display and Sight System (HIDSS). The fully integrated avionics system will allow tactical data to be overlaid onto a digital map, allowing the crew to devote more time for target detection and classification. A triple-redundant fly-by-wire system can automatically hold the helicopter in hover or in almost any other maneuver, reducing workload, allowing the pilot to concentrate on navigation and threat avoidance. A hand-on grip permits one-handed operation.

Stealth characteristics. The Comanche incorporates more low-observable stealth features than any aircraft in Army history. The Comanche radar cross-section (RCS) is less than that of a Hellfire missile. To reduce radar cross-section, weapons can be carried internally, the gun can be rotated aft and stowed within a fairing behind the turret when not in use, and the landing gear are fully-retractable. The all-composite fuselage sides are flat and canted and rounded surfaces are avoided by use of faceted turret and engine covers. The Comanche's head-on RCS is 360 times smaller than the AH-64 Apache, 250 times less than the smaller OH-58D Kiowa Warrior, and 32 times smaller than the OH-58D's mast-mounted sight. This means the Comanche will be able to approach five times closer to an enemy radar than an Apache, or four times closer than an OH-58D, without being detected.
RAH-66 Comanche with landing gear retracted and all weapons "stowed"

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Noise suppression. The Comanche only radiates one-half the rotor noise of current helicopters. Noise is reduced by use of a five-bladed rotor, pioneered by the successful Boeing (McDonnell Douglas) MD-500 Defender series of light utility helicopters. The fantail eliminates interaction between main rotor and tail rotor wakes. The advanced rotor design permits operation at low speed, allowing the Comanche to sneak 40% closer to a target than an Apache, without being detected by an acoustical system.

Infrared (IR) suppression. The Comanche only radiates 25% of the engine heat of current helicopters, a critical survivability design concern in a low-flying tactical scout helicopter. The Comanche is the first helicopter in which the infrared (IR) suppression system is integrated into the airframe. This innovative Sikorsky design feature provides IR suppressors that are built into the tail-boom, providing ample length for complete and efficient mixing of engine exhaust and cooling air flowing through inlets above the tail. The mixed exhaust is discharged through slots built into an inverted shelf on the sides of the tail-boom. The gases are cooled so thoroughly that a heat-seeking missile cannot find and lock-on to the Comanche.

Crew Protection. The Comanche features a crew compartment sealed for protection against chemical or biological threats, an airframe resilient against ballistic damage, enhanced crash-worthiness, and reduced susceptibility to electromagnetic interference.

RAH-66 Comanche Prototype Photos rah66001.jpg rah66002.jpg rah66003.jpg rah66004.jpg rah66005.jpg cpcomcut.gif RAH-66 Comanche prototype cut-away line drawing The Boeing Company RAH-66 Comanche gallery