PRODUCT
INFORMATION
PAGE


ALT-55B


FEATURES
  • Lightweight, low-profile radio altimeter compatiable with Ground Proximity Warning Systems (GPWS)
  • Typically used with ALI-55/55A analog indicators or DRI-55 digital display indicator, and two 437X-1/1A/1B or ANT-50A/51A/52 antennas depending on aircraft configuration
  • Provides decision height selection from 0 to 2500 feet
  • Provides four shop-adjustable altitude trips (-001 unit)
  • Capable of dual system configuration
  • Built-in self-test effectively checks system excluding antennas
  • Version available with altitude error reduction where unit will indicate lower altitude in the event of unit failure thus ensuring safe terrain separation (-01X version - see table below)
SPECIFICATIONS
FAA TSO: C87 RTCA: DO-138, DO-123
FCC Rules: Part 87 Environmental Category: DO-138/AG/A/JN/AAAEXXXXX
Temperature: -54 to 71C (operating) Service Altitude: Up to 55000 feet
Analog Accuracy: +-2 ft. or +-2% Transmitter Power: 350 mW nominal
Frequency Modulation (Transmit): 100 or 105 Hz (selectable) Load Capability: 1 millimho maximum
Time constant: 0.09 +-0.01 s System Accuracy: +-5 ft. or +-5% (0-500 ft)
Power Requirements: +22 to +34 Vdc. 30W (+28Vdc nominal) ARINC: 408

ALT-55B
Part Number Radio Altimeter Transceiver Description:
622-2855-001 -20 to 2500 ft. range with 4 trip shop adjustable trip outputs
622-2855-011 Same as -001 but with reduced altitude error product improvement mentioned above
622-2855-002 -20 to 2500 ft. range with 4 trip non-shop adjustable trip outputs
622-2855-012 Same as -002 but with reduced altitude error product improvement mentioned above


alt55b