Date: 201306
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Light: Night
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Parked
Aircraft component: Oxygen System/Crew
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Airframe; Maintenance Powerplant
Human factors: Communication Breakdown; Situational Awareness
Anomaly: Aircraft Equipment Problem Critical; Ground Event / Encounter Other / Unknown
Detector: Person Maintenance
When detected: Other During Maintenance
Result: Aircraft Aircraft Damaged; General Maintenance Action; General Physical Injury / Incapacitation
Contributing factors: Company Policy; Equipment / Tooling; Human Factors
Primary problem: Equipment / Tooling

Narrative: As I was servicing on one of our airplanes with oxygen (O2) for the Crew [oxygen]; the hose on the O2 service bottle disconnected from the O2 fitting. As this happened the blast from the hose caused hearing loss in my right ear for several days. I was treated for the problem at the doctor and I am progressively getting better. The hose also cut and bruised my right arm and dented the plane which was reported and maintenance action was taken. I just would like to see or know if the service hoses on our o2 bottles and nitrogen service bottle have; or can have; inspections and/or cycle dates. The pressure on the hose at that time was only 1;800 PSI which I know is well below its limits.  Defective hose.  [Recommend] routine Inspection [Work] Cards on hoses [for] hose life limit.

Callback: Reporter stated he was outside on the Ramp servicing the Crew Oxygen (O2) on an EMB-145 aircraft. They use a rubber type servicing hose with a flexible braided metal sheath around the rubber. There is a three inch hard metal line with a 'B' fitting on one end that connects to the external servicing port on the aircraft's fuselage about chest level. Oxygen is then routed directly to the onboard Crew oxygen bottle. The oxygen servicing line from the oxygen cart's supply bottle is attached to the opposite end of the three inch metal line. He was bending over to see if the oxygen pressure in the servicing line from the supply bottle was building pressure; when suddenly the hose separated from the three inch metal line. The blast sounded like a shotgun had gone off next to his ear. Reporter stated the braided metal oxygen hose was snaking violently around under pressure; hitting him in several places including his collar bone and arm and finally wrapping itself around the nose tires before he could shut-off the oxygen supply pressure. His hearing has not returned to normal.  The three inch hard metal line remained attached to the aircraft's servicing port. The rubber hose material had deteriorated at the connection to the three inch line; but was not visible under the braided metal covering. His air carrier has not responded to his suggestion to have at least an Annual Equipment Maintenance Inspection implemented. He now holds onto the supply hose while servicing Crew oxygen.



Synopsis: A Line Aircraft Maintenance Technician (AMT) describes his injuries; including hearing loss; after an oxygen supply servicing hose separated at the Crew oxygen external servicing port on an EMB-145 aircraft.