RAH-66 Comanche, United States of America


The Comanche RAH-66 reconnaissance and attack helicopter was being developed by Boeing and Sikorsky for the US Army. The first flight of the Comanche took place on 4 January 1996. The program entered Engineering and Manufacturing Development (EMD) in June 2000, which requires the construction of nine aircraft in addition to the two prototypes by 2006. Critical design review of the overall weapon system was completed in June 2003 to be followed by low rate initial production of 78 helicopters in three batches in 2007.

In February 2004, the US Army announced that it plans to cancel further research, development and planned purchases of the RAH-66 Comanche stealth helicopter. It considers that the helicopter will not meet the requirements of changing operational environments. An amendment to Congress will be submitted for the 2005 budget request that would allow the Army to terminate the Comanche program and reallocate funds to restructure Army aviation programs. The Army plans to buy approx. 800 more aircraft and upgrade another 400 with the diverted Comanche funds.

The armed reconnaissance Block I version was scheduled for initial operating capability in 2009 and heavy attack Block II version in 2011. The US Army requirement was for 650 Comanche helicopters.

Production of the Comanche would take place at Sikorsky's new site in Bridgeport, Connecticut. Boeing is responsible for manufacturing and assembling the composite tail section and rotor blades and Sikorsky for manufacture of the main fuselage and gearbox and for integration and final assembly of the airframe.

In an armed reconnaissance mission, Comanche can recognise and identify targets, and digitally transmit the information to the battlefield commander in near real-time, select the optimum force deployment and co-ordinate the attack.

DESIGN

The airframe is crashworthy and ballistically tolerant to 23mm gunfire. The radar cross section has been minimised, primarily by the precisely shaped fuselage and internal weapons configuration. The helicopter has a composite five-bladed bearingless main rotor and an enclosed composite fantail tailrotor for increased anti-torque capability. The rear rotor is able to withstand impact by 12.7mm rounds, and provides a 180 degree turn in 4.7 seconds in hover mode and an 80-knot snap-turn-to-target in 4.5 seconds.

COCKPIT

The Comanche has two identical cockpits for the pilot and the co-pilot, which are sealed and have a positive pressure air system for protection against chemical and biological warfare. The fly-by-wire flight control system is triple redundant. The cockpit is fitted with a pilot's night vision system from Lockheed Martin and the pilots have a wide field of view (35º x 52º) Kaiser Electronics Helmet Integrated Display Sighting System (HIDSS). HIDSS employs active matrix liquid crystal display (AMLCD) technology. The targets are designated and the weapons fired from collective and sidestick control push buttons. Each integrated cockpit has Harris Corp. flat screen liquid crystal displays, a colour display for a digital moving map system, tactical situation and night operation display.

Northrop Grumman is providing the Comanche's integrated Communications, Navigation and Identification (CNI) suite. The CNI suite will feature secure multi-wave, multiband multimode wireless communications, Link 16, satellite communications and Enhanced Position Locating Reporting System (EPLRS) via the tactical internet.

WEAPONS

The Comanche carries its weapons internally and has a weapons bay on each side of the fuselage. The missiles are mounted on the weapon bay doors, which open sideways. The internal weapon bay can be fitted with Stinger, Starstreak or Mistral air-to-air missiles; TOW II, Hot II or Longbow Hellfire air-to-ground missiles; Sura D 81mm, Snora 81mm, Hydra 70 rockets; or the army counter air weapon system. The number of missiles on each door mounting varies: for example, each door will hold three Hellfire or six Stinger missiles. The helicopter can be reconfigured with optional stub wings fitted with multiple weapon pylons, which carry an additional four Hellfire or eight Stinger missiles.

The Comanche is equipped with a turreted gun system from General Dynamics Armament Systems. The stowable, externally powered, three-barrel, 20mm Gatling gun is capable of firing 750 or 1,500 rounds per minute. The gun is mounted on a Giat composite turret (weighing 127kg) under the nose of the helicopter. The 500-round ammunition supply system can be reloaded in less than eight minutes by two crew members.

COUNTERMEASURES

The helicopter countermeasures suite includes an AN/AVR-2A(V) Advanced Laser Warning Receiver from Goodrich Electro-Optical Systems (formerly Raytheon) of Danbury, Connecticut and the ITT AN/ALQ-211 SIRCM (Suite of Integrated Radio Frequency Countermeasures) suite, as well as infrared jammers.

FIRE CONTROL AND OBSERVATION

The Comanche is equipped with a suite of passive sensors and a computer-aided Northrop Grumman mission planning system, which carries out sensor data fusion, high-speed analysis and correlation of the sensor data. Northrop Grumman TASS (Target Acquisition System Software) functions include automatic target tracking and target threat management. The analysed data is presented to the crew in the cockpit displays or transmitted to other elements of the force, providing direct relay of near real-time intelligence.

Lockheed Martin Missiles and Fire Control has developed the EOSS (Electro-Optics Sensor System) which comprises: EOTADS target acquisition and designation system, including solid-state TV sensor, two-colour laser rangefinder/designator and second-generation focal plane array long-wave FLIR (forward-looking infrared); and NVPS Night Vision Pilotage System with a second FLIR. The first complete EOSS system was delivered in June 2003.

The Comanche will be fitted with a fire control radar (based on the Longbow millimetre wave radar on the AH-64D Apache helicopter) being developed by Northrop Grumman Land Combat Systems and Lockheed Martin Missiles & Fire Control.

NAVIGATION AND COMMUNICATIONS

The helicopter has a global positioning system, a radar altimeter and an attitude heading reference system (AHRS) from Northrop Grumman (formerly Litton).

It is equipped with an identification friend or foe (IFF) interrogator and a dual jam-resistant VHF-FM / UHF-AM Have Quick tactical communications system.

ENGINES

The Comanche is equipped with two T-800-LHT-801 turboshaft engines from LHTec, with a maximum rated power of 1,563shp each. The internal fuel capacity of the helicopter is 1,142 litres.