RAC has published King Air Series Communique 99-005, dated
October 1999 (copy enclosed). RAC also published Safety Communique
No. 168 (copy enclosed), dated November 1999 and applicable to all
Raytheon Aircraft models with deployable passenger oxygen mask
systems, to ensure that all operators are aware of the importance
of properly installing the doors on the oxygen mask boxes.
ATSB Note: Extracts from the relevant communiques are published
below for clarification:
RAC Safety Communique No 168:
November 1999
TO: All Operators, Chief Pilots, Directors of Operations, Directors
of Maintenance, Raytheon Aviation Centers, Raytheon Aircraft
Authorized Service Centers, and International Distributors and
Dealers
MODELS: All Raytheon Aircraft Models with Deployable Passenger
Oxygen Mask Systems
SUBJECT: Passenger Oxygen Mask Stowage
Raytheon Aircraft Company (RAC) feels it necessary to stress the
importance of properly packing and stowing the Passenger Oxygen
Masks. A recent incident necessitates reminding operators/mechanics
of the maintenance practices involving this safety equipment.
RAC has received a report from Australian CAA Authorities that some
of the passenger oxygen masks installed in a King Air Model 200 did
not deploy during a non-pressurized flight above 12,500 feet.
Further investigation found the auto-deployment system functioned
correctly; however, the oxygen mask container door had not been
reinstalled correctly. If the door is installed 180 (degrees) from
the correct position, the door open plunger cannot strike the block
mounted on the door. This will prevent the door from opening. There
are caution statements in the Model 200 Maintenance Manual, Chapter
35~ pages 215 and 216, which state, "Container door can be
positioned 180 degrees off. If this happens, the plunger cannot
push the door open when activated," and other instructions that
describe the proper way to repack the masks and reinstall the door.
The Phase 1 and Phase 3 inspections require a functional test be
performed of the oxygen system to ensure that the doors on the mask
containers open and the masks drop out.
Due to the above referenced report, Raytheon Aircraft Company is
re-emphasizing the importance of these inspections and correct
installation regardless of aircraft model. Please refer to the
applicable Maintenance Manual when conducting the next mask
inspection/maintenance check.
Excerpt from RAC Comunique No 99-005:
Passenger Oxygen Mask Packing - All
We must once again stress the importance of properly packing and
stowing the Passenger Oxygen Masks. RAC Technical Support has
received a report from Australia Authorities stating that some of
the passenger oxygen masks on a King Air Model 200 did not deploy.
Further investigation found the auto-deployment system functioning
correctly, but the oxygen mask container door had not been
reinstalled correctly during a previous mask inspection. If the
door is installed 180 (degrees) from the correct position, the door
open plunger cannot strike the block mounted on the door and the
door will not open. There are caution statements in the Model 200
Maintenance Manual (Chapter 35-00-00) which warn maintenance
technicians to properly repack the masks and install the door
correctly, but due to the above reference report, we wanted to
re-emphasize the importance of proper installation. Please refer to
the Maintenance Manual if there are any questions at your next mask
maintenance check.
