Date: 201204
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Parked
Aircraft component: Fuel Tank
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Airframe; Maintenance Powerplant
Human factors: Communication Breakdown; Situational Awareness; Workload
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Other During Maintenance
Result: General Maintenance Action
Contributing factors: Aircraft; Staffing; Human Factors; Environment - Non Weather Related
Primary problem: Human Factors

Narrative: At approximately XA:30pm; I went to the Hangar; an A320 aircraft; to make sure that the Fuel Tank Venting equipment was setup and operating. When I got there the blower for the right-hand side Main Fuel Tank was not operating and the blower on the left-hand main was operating at a low level. I made sure that both sides were venting and informed the Shift Supervisor in the Hangar that they had been unhooked.  After approximately 20-minutes; I returned to start sumping the main tanks with other members of the fuel crew to find the right hand blower was unplugged from the air source and not operating. I asked several mechanics on the Hangar floor if they had knowledge of why the blowers air source had been unplugged and they did not. At that time; I told the Supervisor to please brief his Maintenance crew and inform them that the fuel crew needs to purge the tanks for entry. I again made sure that the blowers were operating properly and we left until after break. After break we returned again and now the blower for the left main tank was not operating. This is an unsafe practice and can not be tolerated.

Callback: Reporter stated the air blowers that are used for venting the wing fuel tanks are old and noisy. When the air blowers are in use along with additional air supply hoses attached to venturi type horns positioned in the fuel tanks to increase air movement through the wing fuel tanks during fuel tank maintenance work; the hangar environment is very loud and noisy. The blowers and venturi horns are left running to purge the wing tanks even though the fuel crew is not actually in the tanks. Reporter stated Hangar floor mechanics working on the same airplane get frustrated with the continuous loud noises and when they don't see anyone working in the fuel tanks; they have been known to disconnect the air blowers and even the air supplied to the venturi horns to have a quieter work environment. But that is an unsafe practice; especially if someone is still in a tank and also requires the air blowers to run even longer until the fuel tanks are fully vented. His Air Carrier is slowly buying new and quieter air blowers that should make a big difference in the Hangar noise level in the future.



Synopsis: A Fuel Tank Technician reports about finding their left and right fuel tank; wing venting air blowers had been unplugged from an A320 aircraft in their company Hangar; creating an unsafe work environment.