Safety Recommendation
The Australian Transport Safety Bureau recommends that the Civil
Aviation Safety Authority ensure the adequacy of the maintenance
requirements for calibration, functional test and return to service
of barometric pressure switches used to activate deployment of drop
down passenger oxygen masks in Australian registered pressurised
aircraft engaged in the carriage of fare paying passengers.
CASA intends raising an Airworthiness Bulletin (AWB) to provide
advice on how this feature may be incorporated into maintenance
documentation covering periodic maintenance of barometric pressure
switches in Australian registered pressurised aircraft. CASA's
long-term approach will be influenced by the response of other
aviation authorities to the liaison initiated by CASA as the result
of Recommendation 20020109.
The Civil Aviation Safety Authority issued on 01-October-2002, the
following Airworthiness Bulletins (AWB):
AWB 21-1 Issue "Cabin Altitude Alert Pressure Switch Maintenance
Requirements."
AWB 35-1 Issue 1 "Passenger Oxygen Mask Pressure Switch Maintenance
Requirements"
These AWB can be viewed at
www.casa.gov.au/avreg/aircraft/AWB/index.htm
