Part #: 822-1294-432

Model: TTR-4000

Collins Aerospace - TCAS R/T 4MCU AC/DC
Part Number :
Rockwell Collins logo

  • TCAS II Receiver / Transmitter
  • Typically used in the Rockwell Collins TCAS-4000 System
  • 4MCU package that weight approximately 17 pounds
  • Incorporates all Radar Surveillance & computer processing functions for collision avoidance
  • Can be mounted in the electronic equipment bay or outside the pressure vessel
  • Requires 1/3 less space & is 15% lighter than predecessor TCAS II units
  • Incorporates Change 7 logic as standard
  • NOTE: Change 7.1 logic standard on certain models & upgrade available on previous models - See P/N Chart below
  • Can be powered from either AC or DC source
  • Efficient receiver architecture for growth toward future applications
  • Built-in provisions for hardware & software upgrades
  • Designed to fit the installation requirements of most business & regional turbine aircraft
Weight: 17.7 lbs Dimensions: 7.62" H x 5.01" W x 12.56" L
TSO: C-119b Software: DO-178B Level B
EUROCAE: ED-14B Environmental: DO-160D[A2F2] BAB[CYLM] EXXXXZ[BZ] AZC [WWP]M[Z3Z4]A
Temperature: -55 to +70°C  Altitude: 55,000 ft
Power Requirement: 28 Vdc 4A or 155 Vac 1A Transmitter Power Output: Variable, 400 W max
Transmitter Frequency:  1030 ± 0.01 MHz Receiver Sensitivity: -85dBm, ± 2dB
Receiver Frequency: 1090 ± 3 MHz Display Type: Gas discharge
Brightness Control: Automatic or external potentiometer Surveillance Range: 30 nmi, typical 14 nmi, minimum
Surveillance Capacity: 150 targets, 30 displayed Bearing Accuracy: 5° RMS, 10° peak on standard ground plane
Part NumberR/T Description:
822-1294-002 28 Vdc or 115 Vac (can be upgraded to -032)
822-1294-032 Standard Version w/Change 7.1 
822-1294-402 Helicopter Version (can be upgraded to -432)
822-1294-432 Helicopter Version w/Change 7.1


- TCAS II Processor (Change 7.1, Helo)
Price Condition Status

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

TCAS II Version 7.1 mainly incorporates two important changes in relation to resolution advisory thresholds and pilot commands.

The first important change involves the monitoring of Resolution Advisory (RA) compliance. That is, when a TCAS II detects after a certain period of time that an aircraft is not responding correctly to the RA, a reversal RA will be triggered to immediately adjust to the other aircraft not complying with the RA.

The second change relates to the "Adjust Vertical Speed" RA issued by the TCAS that requires the decrease in VS to 2000, 1000, 500, or 9 feet per minute. In some cases, pilots were increasing their vertical speed instead of decreasing it. Some aviation representatives concluded that the "Adjust Vertical Speed" aural alert was not direct enough even though the visual RA was present as well. As a result, instead of retraining crews on TCAS procedures, the "Adjust Vertical Speed" RA is replaced with a simple "Level Off" RA. The RA display visually depicts the same "Level Off" command.

Utilizing more than one antenna to improve the quality and reliability of radio signal is called antenna diversity.

Heavy and/or faster aircraft utilize top and bottom antenna configurations to eliminate the possibility of signal blind spots caused by shadowing. Lighter, slower general aviation aircraft typically only have 1 antenna and do not require antenna diversity. Although not completely uniform, the transmission pattern of a typical antenna provides adequate radiation above and below in relation to most GA aircraft even when the antenna is on the bottom of the aircraft.