01/22/25
Message Overview:
Message Description:
No RAD ALT data received at (L-IOC, R-IOC, TCAS).
Possible Causes:
- Radio Altimeter Transceiver (RAD ALT 4000) (A32)
- Radio Altimeter Antennas (E8) (E9)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Full Throttle Blog/Forum Articles/Infoservice/Newsletter: None
Flight Operation Notifications Manual (FONM): None
Quick Links:
| Standard Aircraft Configuration for Maintenance | AMM 12-00-00-867-803 |
| Electrical/Electronic Safety Precautions | AMM 24-00-00-910-801 |
| Electrostatic-Discharge Safety Precautions | AMM 24-00-00-910-802 |
| Connect Electrical Power to the Aircraft | AMM 24-00-00-861-801 |
| Remove the Electrical Power from the Aircraft | AMM 24-00-00-861-802 |
| Removal of the Radio Altimeter Transceiver | AMM 34-44-01-000-801 |
| Installation of the Radio Altimeter Transceiver | AMM 34-44-01-400-801 |
Troubleshooting Recommendations:
- Reset RAD ALT (CB1-A7) circuit breaker.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Confirm the presence of the 28 VDC and the grounds at Radio Altimeter Receiver connector A32P1. Repair/replace as required.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Verify the antennas (E8) (E9):
- Make sure no corrosion or water ingress is found between the antennas and the skin.
- Inspect the connectors for proper installation or damage.
- Also is recommended to verify the Electrical bonding resistance of the Rad Alt Antenna as per SPM 51-80-00-760-802.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Replace Radio Altimeter Receiver.
- If fault remain, replace Antennas.
- Do close out.