AVIATION OXYGEN MAINTENANCE
AIRCRAFT OXYGEN MAINTENANCE is mandated by the equipment manufacturers in coordination with the standards set by the various international aviation authorities.** Each component of the aircraft oxygen assembly must be inspected and then repaired or overhauled according to a specific schedule.
CREW OXYGEN MASKS
- Constant Flow Masks—designed for use in non-pressurized factory aircraft and are approved for use to FL250.
- Diluter Demand Masks—designed for use in pressurized factory aircraft, and are approved for use to FL400.
- Pressure Demand Masks—designed for use in pressurized factory aircraft, and are approved for use to FL450.
Generally speaking, the overhaul of almost all diluter and pressure demand Crew Oxygen Masks are every six years.
As the older crew masks are phased out—Zodiac Series 893. 359, 10100, 10800 and BE Aero Series 1740, 1741, 1742 series— six years will be standard. All diluter and pressure demand Crew Oxygen Masks must be approved by the FAA and receive 8130 certification and assigned TSO C78A, C89A and or C99A
OXYGEN CYLINDER ASSEMBLY COMPONENTS
- Tanks—either 3HT, 3AA, Kevlar or Aluminum
- Pressure Regulator/valve assembly
- Altitude Compensating Units (optional feature in several aircraft)
The 3HT steel tank has a service life of 25 years, with a hydrotest required every 3 years.
The 3AA steel tank has an unlimited service life, with a hydrotest required every 5 years.
The Kevlar composite (wrapped aluminum) has a service life of 15 years, with a hydrotest required every 5 years.
The Aluminum (flat-bottomed) tank has an unlimited service life, with a hydrotest required every five years.
The pressure regulator (and or altitude compensating unit) must be inspected at every hydrotest; and overhauled at the changeout of the tank or at hydrotest, if indicated by the inspection.
**FAA (USA), EASA (EU/JAA), ICAO (UN), CAA (UK, China), TC (Canada) etc