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Radar Altimetry


Part #: 8010000653-6 NSN 5841-01-301-4588
Part #: 8010000788-1 NSN 5841-01-349-9175


The CARA is a technologically superior and qualified, all solid-state radar altimeter. It provides analog and digital outputs for use by aircraft avionics systems.

Part Number 8010000653-6 NSN 5841-01-301-4588
Part Number 8010000788-1 NSN 5841-01-349-9175

Download CARA Brochure

Signal Data Converters (SDC) are available with the following interfaces:
  • Mil-Std-1553B
  • ARINC 429
  • ARINC 552
  • RS-232
  • RS-422
  • Various analog, discrete and special interfaces



The CARA Receiver-transmitter (RT) transmits a signal to the earth’s surface, receives the reflected signal, processes the information, and provides the resulting altitude-related data from 0 to 50,000 feet to various avionics systems. The system is designed to meet the stringent environments of present and future applications and is compatible with both high and low altitude high-performance aircraft.

Interfaces contained in the RT are sufficient to interface with many basic applications, however, in order to accommodate the multitude of electrical interfaces contained in various aircraft types, Signal Data Converters (SDCs) are used to interface the RT to many avionic systems.

Because CARA is the United States Air Force’s common altimeter, it is compatible with many retrofit and forward-fit installations, and offers performance capability and versatile functions not found in other radar altimeters. Low life cycle cost, which was a primary goal for the CARA design, is inherently obtained from the high system reliability, unique multi-SRU modular construction and automatic self-test with fault isolation to the line replaceable units (LRUs).

CARA is interfaced and qualified with multiple safety-critical functions, including:

  • Automatic landing systems (on aircraft so-equipped)
  • Manual landings in all aircraft, especially under conditions of reduced visibility
  • Automatic Terrain-Following (ATF) systems (e.g., F-16 and F-15 with LANTIRN, Sniper, etc.)
  • Ground Collision Avoidance Systems (GCAS, in most USAF platforms)
  • A-GCAS in the F-16

  • Automatic Dependent Surveillance-Broadcast (ADS-B)
  • Traffic Collision Avoidance System (TCAS II)

Initiated over 20 years ago, NavCom’s proactive DMSMS program ensures CARA sustainability through 2050 and beyond.

The radar altimeters replaced and the aircraft installations are:

NavCom, the only qualified OEM, produces and maintains the CARA system in accordance with the latest qualified OEM procedures, drawings, piece-parts and workmanship standards.