Two Line Mechanics reported a wing fuel pump change that resulted in a fuel spill when the pump and slide valve fell out of the A320. Examination of the pump found a bent stop pin; retaining pin and spring assembly loose; that prevented the slide valve from being retained by the pump canister; allowing fuel to freely exit the aircraft.
Synopsis
Two Line Mechanics reported a wing fuel pump change that resulted in a fuel spill when the pump and slide valve fell out of the A320. Examination of the pump found a bent stop pin; retaining pin and spring assembly loose; that prevented the slide valve from being retained by the pump canister; allowing fuel to freely exit the aircraft.
Narrative
Mechanic 'X' and I where assigned to perform an A-Check Job Card: the removal of fuel pumps 21QA - 25QA -22QA -and 26QA to check for detached labels within the pump and canister. As per the AMM Task 28-21-51; we [were] in the process of positioning the extractor-fuel pump tool hooks in the pump holes; as instructed on Step 15 of the Task; when the pump and slide valve fell out of the plane into my hands. Attempts to replace the pump past the flow of fuel were not successful and approximately 58 gallons of fuel were spilled before the spill response team could stop the spill.Upon investigation of the pump; slide valve; and pump canister; we found a bent stop pin; as well as the two screws and retaining plate that holds the retaining pin and spring assembly were loose and caused the pin to wobble. With the retaining pin and spring assembly loose; [one cannot]properly retain the slide valve within the canister; while the pump is removed. With the slide valve removed; as well as the pump; fuel is free to exit the aircraft. There were no injuries or aircraft damage due to this situation.
Second reporter narrative
While Mechanic 'Y' and I were performing Steps 15 and 16 of (Maintenance Manual) MM 28-21-51; the slide valve and fuel pump came out together. This caused a small fuel spill. Found retaining pin spring assembly faulty and stop pin bent.
More incidents for this aircraft family →
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.