Date: 201909
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: A319
Operator: Air Carrier
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Airspace: Class B ZZZ
Aircraft component: Fan Reverser
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Powerplant; Maintenance Airframe
Human factors: Time Pressure; Training / Qualification; Communication Breakdown
Second reporter function: Technician
Anomaly: Aircraft Equipment Problem Critical; Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural MEL / CDL
Detector: Person Flight Crew
When detected: In-flight
Result: General Maintenance Action; General Flight Cancelled / Delayed
Contributing factors: Human Factors; Procedure; Manuals; Logbook Entry; Equipment / Tooling; Company Policy; Aircraft
Primary problem: Procedure

Narrative: Working at the terminal in training status as assigned by ZZZ training coordinator. It was brought to my attention that aircraft XXXX on landing at ZZZ1 flight XXXX had no thrust reverser operation on #1 engine. The previous evening I worked log page XXXXXXX air engine 1 hp valve fault. I was assigned to pick up this job already in progress and started by afternoon shift on gate C20. My direction issued by my lead was that this job was previously in progress to MEL for a live flight but midnight shift was given a turnover to replace the HP and PRV valves troubleshot by afternoon shift; and the aircraft flight was changed to RON status.When we arrived at gate C20 #1 Engine was open and the LH T/R was open. The move crew was already at gate C20 prepping to move the aircraft to C26. There was some discussion in planning the logistics for the job and why it was necessary to move the airplane to a different gate while the job was already started and the engine was open. As a result; the engine had to be closed to move the aircraft. As the job progressed; we reopened the engine; replaced the HP and PRV valves; completed operations checks and closed engine for run.It was discovered in ZZZ1 that the HCU for #1 engine was deactivated with a lockout pin. While I worked the aircraft I was unaware the HCU was locked out and I did not install the lockout pin in the HCU. No streamer associated with this lockout pin was visibly noted that is typically attached to the HCU lockout pin. And it should be noted that if the correct streamer associated with the lockout was used; it would have been easily discovered due to a very long length streamer. We locked out the entire aircraft in a powered down state; with flip chart placed in center pedestal noting do not flip any switch.An update to log page XXXXXXX stating locked out #1 engine T/R HDC for maintenance on HP valve was determined to only be the lockout for the HP valve as defined in the MEL 36-XX-X-X. It appears the shipset lockout pin was used to deactivate the HCU and was not removed upon job completion due to the confusion on job turnover from shift to shift; repositioning the airplane to a different gate; failure of no verbal turnover from the afternoon shift to midnight shift mechanics; and the impact of working in inclement weather.A separate log for each device locked out. The ship set lockout pin be replaced and maintained with a long enough steamer so it cannot be missed.


Second narrative: It was brought to my attention aircraft XXXX on landing at ZZZ1 had no thrust reverser operation on #1 engine. The previous evening I worked log 'air engine 1 hp valve fault' I was assigned to pick up this job already in progress and started by afternoon shift on gate XX. My direction issued by my lead was that this job was previously in progress to MEL for a live flight but midnight shift was given a turnover to replace the HP and PRV valves troubleshot by afternoon shift; and the aircraft flight was changed to RON status.Initially; I started this job task by looking up necessary parts prior to going to the aircraft. While looking up the HP valve and PRV there was needed clarification that required me to contact [Maintenance Control] for verification of part identification. While working with my partner; the lead and [Maintenance Control] there was approximately delay of an hour to sort the issue.When I arrived at gate C20 #1 engine was open and LH t/r was open. Move crew was already at gate XX prepping to move aircraft to XX. There was some discussion in planning the logistics for the job and why it was necessary to move the airplane to a different gate while the job was already started and the engine was open. As a result; the engine had to be closed to move the aircraft. As the job progressed; we reopened the engine; replaced the HP and PRV valves; completed ops checks and closed engine for run. It was discovered in ZZZ1 that the HCU for #1 engine was deactivated with a lockout pin. While I worked the aircraft I was unaware the HCU was locked out and I did not install the lockout pin in the HCU. NO streamer that is typically attached to the HCU lockout pin was present; and it should be noted that the streamer associated with the lockout of this device has a very long length that is easily detected. We locked out the entire aircraft in a powered down state; with flip chart placed in center pedestal noting 'do not to flip any switch.'An update to log stating 'locked out #1 engine t/r HDC for maintenance on HP valve' was determined to only be the lockout for the HP valve as defined in the MEL. It appears the ship set lockout pin was used to deactivate the HCU and was not removed upon job completion due to the confusion on job turnover from shift to shift; repositioning the airplane to a different gate; failure of no verbal turnover from the afternoon shift to midnight shift mechanics; and the impact of working in inclement weather.


Synopsis: Technician reported that the #1 engine HCU was locked out by the previous shift and was not documented; subsequently the aircraft flew with the lockout pin still in place.