Date: 201409
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Light: Night
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Aircraft component: Radio Altimeter
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Airframe; Maintenance Powerplant
Human factors: Communication Breakdown; Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Other Paperwork Audit
Result: General Maintenance Action
Contributing factors: Chart Or Publication; Human Factors; Incorrect / Not Installed / Unavailable Part
Primary problem: Human Factors

Narrative: I was assigned to work a B737-700 aircraft with a #2 First Officer (F/O) Radio Altimeter (R/A) discrepancy on a Routine Overnight (RON) Maintenance shift. While working the FO's radio altimeter discrepancy; I performed a Bite check which verified that the #2 radio altimeter had failed. I utilized the AMM and FIM manuals to troubleshoot and facilitate the repair. I return to the shop to find that [stores] AOG had shipped in a TRAX part which was assigned to the B737 predraw and verifying the part was the one assigned for installation on the predraw list; I installed the part and performed the proper maintenance steps to verify the aircraft Radio Altimeter System worked normally and had a CAT III Mechanic recertify the aircraft back to CAT III status. I was informed by a Mechanic and local Supervision that there was an issue with the radio altimeter part I installed on the B737-700 aircraft. Apparently the RA Transceiver assigned to the B737 via TRAX predraw was not correctly configured for the aircraft. There was no documentation in the AMM nor on the Predraw or Parts Tag that stated the Transceiver must me changed in like ship sets. I was unaware that this could happen because it has always been told to us that TRAX program verifies proper configuration; [because] we must check manually for other aircraft that [come under] a different Maintenance Computer Program that [we also] use. [Suggest] a user friendly version of our Maintenance Computer Program [be applied] in Trax to verify part compatibility for our aircraft  that come under the Trax Maintenance Records System. Graveyard Shift.

Callback: Reporter stated there was no information available under their TRAX Maintenance Parts Program for the B737-700 aircraft he was working that stated the Part Number (P/N) on the First Officer's RA Transceiver he was replacing had to match the Captain's RA Transceiver P/N. If not; both transceivers had to be replaced with similar P/Ns due to software cross-talk capability requirements. That's what he was referring to when he mentioned the transceivers must be changed in Ship Sets. He has fifteen years experience in aircraft maintenance.



Synopsis: A Line Aircraft Maintenance Technician (AMT) describes how the lack of information in their Aircraft Maintenance Manual (AMM); Maintenance Parts Tracking Program and Parts Tag contributed to his replacing a First Officer's (F/O) Radio Altimeter (RA) Transceiver with a part number different than the Captain's RA Transceiver p/n on a B737-700 aircraft.