Date: 201503
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: Large Transport
Operator: Air Carrier
Operating under: Part 121
Flight phase: Parked
Aircraft component: Fuel Tank
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Powerplant; Maintenance Airframe
Human factors: Physiological - Other; Communication Breakdown; Situational Awareness; Distraction
Anomaly: Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Other During Maintenance
Result: General Maintenance Action
Contributing factors: Procedure; Human Factors; Equipment / Tooling; Company Policy
Primary problem: Procedure

Narrative: The issue is our fueling and defueling procedures in the hangars which result in employees being exposed to high amounts of fuel vapors. These vapors are often strong enough to cause eye irritation; and even a bit of dizziness.  In addition to the health and safety issues; releasing fuel vapors into the atmosphere puts the Air Carrier at risk of environmental non-compliance. There are state; regional; and local air quality regulatory agencies that enforce strict standards here in the ZZZ area.  Several months ago; I was able to have local safety representatives witness the fuel tank sumping and venting process on a plane in our hangar. They all agreed there is an issue; but it seems the solution is beyond the local level as it involves our Air Carrier's fueling procedures as they pertain to ZZZ Maintenance Base; training; as well as Base equipment.The primary component used in sumping fuel from tanks is an air driven vacuum head placed on top of a 55-gallon drum or a fuel bowser. These air driven devices release fuel vapor in their exhaust air. Fuel tank venting is accomplished with portable air driven; air movers connected to soft plastic tubing that inflates with the venting gases. This tubing is directed through the hangar doors; and into the open air. Anyone approaching the hangar will come in contact with these fumes. There is a possibility our Air Carrier is risking non-compliance with air quality regulations here in the ZZZ area by releasing these fumes into the air. The plastic tubing is often crushed or damaged by equipment and personnel. It's not uncommon to see vehicles parked on these tubes. There is also the question whether these tubes are adequately grounded.[Our] Air Carrier had a system in place for venting fuel tanks that was built into the hangars. This system was deactivated at some point; but parts of it still remain in the narrow body hangars. The ducting this system used was never on the hangar floor where it would be vulnerable to damage or compromise from vehicles or other equipment. It also prevented any fuel vapors from entering the hangar. Our Air Carrier's venting process called for a flow of fresh air into the fuel tanks; and for vapor filled air to be drawn out of the tanks. The current process directs mechanics to open all the fuel access plates; resulting in a reduced flow of air through the tanks; and release of vapors into the work environment. I have info on how the equipment is being used.




Synopsis: An Aircraft Maintenance Technician (AMT) reports that the current fueling and defueling procedures in their maintenance hangars result in employees being exposed to high amounts of fuel vapors; environmental non-compliance; and an unsafe workplace. A previous system of fuel tank venting did not allow vent ducts on the hangar floors.