A321
Maintenance Airframe; Maintenance Powerplant
Maintenance Lead Technician 10; Maintenance Technician 15
Training / Qualification; Situational Awareness; Communication Breakdown; Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural MEL / CDL; Inflight Event / Encounter Other / Unknown
Flight Crew Overcame Equipment Problem; General Maintenance Action
Chart Or Publication; Human Factors; Manuals; Aircraft
I had an A321 aircraft inbound for an Additional Center Tank-1 (ACT-1) failed to transfer fuel write-up. So; I called Maintenance Control; we then agreed to MEL the discrepancy. The MEL required me to deactivate the ACT Transfer Valve in the 'closed' position. I followed the Aircraft Maintenance Manual (AMM) 28-28-00-040-A. After the aircraft left; got a call from Maintenance Control saying the pilot reported that he was getting fuel from ACT-1 tank. After reading the AMM reference over again and talking to a few fellow mechanics; I realized I may have inadvertently locked the valve in the 'open' position. Causes were due to miss-reading the Transfer Valve Indicator; poor lighting; incorrect ladder that gave me an awkward angle for viewing the valve and indicator. Pilot reported [discrepancy] due to fuel being transferred from the ACT-1. The incident was already corrected once I was notified about it. Notified Maintenance Control Duty Manager about this event. [Recommend] to have a second mechanic witness the valve position.
Reporter stated the A321 has an Additional Center Tank (ACT) where extra fuel can be added and is transferred to the Main Center Tank during 'Normal' operations. The ACT has its own fuel pump. The ACT Transfer Valve Motor actuator is located in the Main Wheel Well at the forward bulkhead. The Transfer Valve Motor actuator can be separated from the Transfer Valve and replaced as a Line Replaceable Unit (LRU). The original logbook discrepancy noted the Transfer Valve would not open and allow fuel to transfer to the Main Center Tank. There was approximately 5;000 pounds of fuel in the ACT-1 tank. So he and Maintenance Control decided to defer the valve due to no replacement parts available at ZZZ1. Reporter stated the text in the Aircraft Maintenance Manual (AMM) is very clear and states to manually position the Motor actuator part of the Transfer Valve to the 'horizontal' position which would be the 'closed' position. But there are four reference pictures in the AMM: two pictures showing the Forward Indicator position of the Motor Actuator and two pictures showing the Aft Indicator on the Motor Actuator at the wheel well forward bulkhead. The reference pictures are confusing as to which indicator he should be using. He apparently rotated the Motor Actuator shaft to the 'open' position; which he thought was the 'closed' indication on the Motor Actuator. That's why fuel was later found to have been pumped from the ACT-1 to the Main Center Tank even though the MEL Maintenance Procedure and the logbook sign-off stated the ACT-1 Transfer Valve was 'closed' and fuel unavailable. A similar incident where the Transfer Valve Motor Actuator was rotated to the 'open' position instead of the 'closed' position has already occurred on another one of their A321 aircraft since his incident.
June morning 2014; in ZZZ; MEL 28-28-01B was applied to an A321 aircraft in the logbook. The MEL calls for the Additional Center Tank (ACT) Transfer Valve to be deactivated 'closed' and the amount of fuel trapped in the ACT to be recorded for Center of Gravity (C/G) calculations. Later in the day; I; Maintenance Controller X; was contacted by Dispatch. The flight crew was asking to have the MEL Maintenance Procedure [for deactivation of the ACT] to be verified on arrival in ZZZ1; because there was now; no fuel in the ACT's. Our Air Carrier Maintenance in ZZZ1 checked the Maintenance Procedure In Accordance With (IAW) the Aircraft Maintenance Manual (AMM) 28-28-00-040-008; and found that the valve was deactivated in the 'open' position instead of the 'closed' position. This was documented in logbook. At the time of MEL application; there was fuel in the ACT; later it was empty. The only way for fuel to move out of the ACT's is through the 'open' Transfer Valve. When the aircraft reached the gate in ZZZ1; it was determined by Maintenance that the valve was 'open'. Accomplished AMM 28-28-00-040-008; and secured valve in the 'closed' position.
A Line; Lead Aircraft Maintenance Technician (AMT) and a Maintenance Controller describe their involvement with an MEL deferral of an Additional Center Tank (ACT) Fuel Transfer Valve that was incorrectly moved to the 'open' position instead of the 'closed' position; on an A321 aircraft. Lead Technician also notes the reference pictures in the Aircraft Maintenance Manual (AMM) for the Transfer Valve Motor actuator position indicators are confusing.