Date: 201403
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Light: Night
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Parked
Aircraft component: Elevator
Component problem: Malfunctioning
Reporter organization: Contracted Service
Reporter function: Lead Technician
Reporter qualification: Maintenance Powerplant; Maintenance Airframe
Human factors: Situational Awareness; Training / Qualification; Communication Breakdown
Second reporter function: Inspector
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
Detector: Person Flight Crew
When detected: In-flight
Result: General Maintenance Action
Contributing factors: Incorrect / Not Installed / Unavailable Part; Human Factors; Chart Or Publication; Aircraft; Procedure
Primary problem: Chart Or Publication

Narrative: I was made aware of an incident regarding an aircraft I was involved in for removal and installation of an aircraft elevator. During the aircraft visit I was the Technician providing maintenance to our Customer's aircraft. The work involved required dis-assembly and re-assembly of various consumable parts on the elevator. During a high speed descent; a flight crew reported to their airline a flutter or tail vibration. Upon further investigation of the customer airline; it was discovered one or more Elevator Servo-Control bushings were not installed. It is possible I may have inadvertently left the bushing or bushings out upon re-assembly. It is also possible another Technician completed the assembly and I signed behind the Technician that actually performed the work; as is commonplace here. The procedure did not require; at the time; an RII Inspection during the assembly process for this flight control. This may have assisted in identifying any missing parts if an RII inspection was mandated for this primary flight control.The procedure at the time of maintenance was a task card assigned by the customer and was a one line sign-off item. However; the task required printing out approximately several dozen pages of the Aircraft Maintenance Manual (AMM) to remove and install the associated elevator. A breakdown of the work into various steps with interval required RII inspections may have prevented this incident from occurring. Our company carries a Shift Turnover Report; to assist in logging information when it cannot be completed during the same shift. The shift turnover also does not dictate a required RII Inspection. Other contributing factors may have been that at this juncture I was working possibly 12-hour shifts and that I was also involved in working on other assigned tasks. When returning to this task; I may have inadvertently skipped that step. As it is; I should have determined the bushing or bushings were not installed during the assembly process as I am the responsible Technician that signed for the work.

Callback: Reporter stated he was referring to the two Power Control Units (PCUs) that move each Elevator on the A320 aircraft when he mentioned the Servo-Controls. He was informed that internal bushings for both PCU rod ends were missing where the rod ends attach to the forward side of each elevator. He has not seen any revisions in the Job Cards or an RII Inspection Item added to improve the installation procedures.

Second narrative: I was made aware of an incident regarding an aircraft I was involved in for inspection of aircraft elevators. The particular aircraft had its elevators removed and re-installed for dimensional checks. During the Maintenance Visit (M/V) the Customer provides Task Cards to accomplish. After elevator installation the inspection was not identified as a Required Inspection Item (RII) on the associated Task Card. The instruction for installation of the elevators was to utilize the Aircraft Maintenance Manual (AMM) and sign-off was accomplished with a single line on the Task Card. During this time the Job Card did not require an RII Inspection of the Elevator Assembly. Upon completion of the technicians work I inspected the Final Task. The inspection and installation was recorded using the Aircraft Maintenance Manual (AMM) and documented on a Shift Turnover Report; a company provided form; where work 'in progress' can be documented. Upon completion of the Maintenance Check the aircraft was returned to service. After approximately several months in service; a flight crew reported a tail vibration during high speed descent. Further troubleshooting for the vibration revealed the finding that a bushing or bushings for the Elevator Servo-Control may not have been installed during the Maintenance Visit. The airline Customer informed my company of the discrepancy. My recommendation for installation documentation of this Primary Flight Control would be to break the AMM down into several job steps in lieu of one large job step of approximately 60 pages. While recently accomplished by the airline; the Job Card should then have already mandated an RII requirement during assembly of a primary flight control. Had this been implemented; at a minimum it is highly unlikely the Technician would not have inadvertently left out the affected part; it would have also allowed this Inspector to identify any missing parts or components.


Synopsis: A Contract Repair Station Technician and an Inspector were informed that the flight crew of a customer airline's A320 aircraft had reported a flutter/tail vibration during a high-speed descent. Bushings for the Elevator Power Control Unit (PCU) rod ends were missing at the PCU attachments to the Elevator.