Honeywell (Hall 5, Stand B11) has won initial certification for its new AH-900 Attitude Heading Reference System (AHRS), which will supply increased-reliability information to aircraft autopilots and electronic attitude displays.
The new system has been approved under the aircraft type certificate for Embraer (Hall 2A, Stand E15) regional jets.
AH-900 uses digital ring-laser gyros and quartz accelerometers to keep track of changes in aircraft heading and attitude. It is standard equipment on the Embraer ERJ 135, ERJ 140 and ERJ 145 regional jets and will be standard on the new Fairchild Dornier 328JET later this year.
Once initialised at the beginning of the day, the system can fly up to 18hr and 18 separate flight legs while maintaining compass accuracy within a typical one degree without the aid of a flux valve.
Mean time between failures is 14,000 hours, compared with 7,000 or less for previous-technology systems using mechanical sensors such as pendulum-based accelerometers and spinning-mass gyros.
Honeywell says the AH-900's accuracy improves the performance of the aircraft's autopilot and satellite communications, and prepares the aircraft for the advent of future broadband satellite communications, such as direct-broadcast TV, which will require accurate antenna pointing. A low-cost upgrade will allow it to act as the heart of an inertial navigation system (INS) or GPS/INS. This will allow equipped aircraft to fly in high-density traffic areas governed under the coming Communication, Navigation, Surveillance/Air Traffic Management (CNS/ATM) operational standards.
The upgrade, in conjunction with a head-up display, will also support instrument landings to Category IIIa standards (600ft required visibility).
Source: Flight Daily News
