Part #:

Model: TRA3500

FreeFlight - Radar Altimeter System
product image
Part Number :


  • Lightweight radio altimeter transceiver designed for transport category aircraft, helicopter, and seaplane operations
  • Used in conjunction with TRI-40 (14 Volt) Indicator and dual antenna system
  • "Anti-hover" capability prevents altitude wandering while hovering in helicopter
  • Provides precise AGL information from 2500 feet down to ground level
  • 28 Volt power input
  • ARINC analog outputs allow integration with other on-board equipment such as flight director systems
  • Internal gear warning light aural and visual out
  • Eight fixed trip point outputs
Dimensions: 1.375"W x 2.5"H x 7.5"L Weight: 3.25 lbs.
Power Requirements: 27.5 VDC, 750 mA Transmit Power: 20 mW minimum
Frequency: 4.3-GHz center frequency sweep, 4.25 to 4.35 GHz Accuracy: 40-100 ft. +-5 ft 100-500 ft. +-5% 500-2500 ft. +-7%
Part Number Radar Altimeter Description:
1901-3500-00 Basic TRA-3500 (Unit Only)
TRA-3500/TRI-40 Shipset 1  Complete System (Basic TRA-3500 Version)
TRA-3500/TRI-40 Shipset 2 Complete System (with Alt Trip Points)
TRA-3500/TRI-40 Shipset 3 Complete System (with NVG)
TRA-3500/TRI-40 Shipset 4 Complete System (with Alt Trip Points & NVG)
* "Shipset" Part Numbers are for REFERENCE ONLY - Items must be purchased separately. Attached PDF listings are for Reference Only & are subject to change.


Click on a question below to see the answer. If you have a question about this model that is not answered below, please contact

Although not a direct replacement, the FreeFlight RA-4500 can be used to replace the Receiver/Transmitter in the TRA-3500 radar altimeter system.  Please order/reference the RA-4500 Sensor System.

Yes. Free Flight uses part number 9-1203-115-00 in their catalog and installation manual for the radar altimeter antenna used in their RA3500, RA4000, and RA4500 systems. When you inspect these antennas, they are packaged in a Sensor Systems box with the 9-1203-115-00 part number label on the outside of the box. When you open the Sensor Systems box, you can immediately see that it is actually the Sensor Systems S67-2002 antenna. The antenna has the S67-2002 part number on its dataplate.