Back to top
Output Number
IR19990150
Approval Date
Published Date Time
Recommendation type
Interim recommendation
Mode
Aviation
Date released

The Bureau of Air Safety Investigation recommends that Raytheon
Aircraft develop and publish methods for the in-situ testing of the
automatically deployable passenger oxygen activation system and the
cabin altitude alert system on Beechcraft aircraft, to ensure
complete system operation.

As a result of the investigation into this safety deficiency,
the Bureau simultaneously issues the following interim
recommendations:

IR19990151

The Bureau of Air Safety Investigation recommends that the Civil
Aviation Safety Authority reassess the appropriateness of the
current maintenance procedures for the testing of automatically
deployable passenger oxygen systems and cabin altitude alert
systems, to ensure complete system operation.

IR19990152

The Bureau of Air Safety Investigation recommends that the
Federal Aviation Administration reassess the appropriateness of the
current maintenance procedures for the testing of automatically
deployable passenger oxygen systems and cabin altitude alert
systems, to ensure complete system operation.

IR19990153

The Bureau of Air Safety Investigation recommends that Raytheon
Aircraft consider the incorporation of an audible warning to
operate in conjunction with the cabin altitude alert system on all
Beech aircraft so equipped.

IR19990154

The Bureau of Air Safety Investigation recommends that the Civil
Aviation Safety Authority consider the incorporation of an audible
warning to operate in conjunction with the cabin altitude alert
system on Beech aircraft, and other aircraft so equipped.

IR19990155

The Bureau of Air Safety Investigation recommends that the
Federal Aviation Administration consider the incorporation of an
audible warning to operate in conjunction with the cabin altitude
alert system on Beech aircraft, and other aircraft so equipped.

 

Organisation Response
Date Received
Organisation
Raytheon Aircraft
Response Status
Monitor
Response Text

In accordance with Interim Recommendation IR19990150, RAC has
reviewed the B200 Maintenance Manual Procedures for Functional Test
Procedure of the Oxygen Auto-deploy System, and finds it
appropriate for the system. However, there is no functional test
for either of the barometric switches (one for the oxygen system
and one for the annunciator system) installed in the airplane. RAC
will add a procedure to the maintenance manual to functionally
check the barometric pressure switches.



RAC reviewed the maintenance manual and found that there is a
"press to test" (which checks the annunciator lights). In the
oxygen system functional test procedure, one of the steps is to
verify the oxygen indicator light (green, in the caution/advisory
panel) is illuminated. These tests meet the certification
requirements for the airplane. Therefore, RAC plans no revisions to
the Maintenance Manual with regard to functional test of the oxygen
system.

ATSB Response

The following correspondence from the ATSB was forwarded to RAC
on 22 March 2002.



In regards to the above recommendation made on the 7 October 1999,
to Raytheon Aircraft and your response dated 10 July 2000
(A947-00-07-L03), we have reclassified your response to 'Monitor'
as we have not seen the changes to the King Air aircraft
maintenance manual. This is a new classification that was not
available at the time of our initial assessment to your
response.



In your response dated 10 July 2000 to the ATSB recommendation IR
19990150 you have indicated that;



"RAC will add a procedure to the maintenance manual to functionally
check the barometric pressure switches".



Could you please supply us copies of the relevant section/s of the
amended maintenance manual/s?



To ensure that all aspects of the ATSB recommendation IR 19990150
are addressed could you please provide the relevant information
that shows that the test procedures for the automatically
deployable passenger oxygen activation system and the cabin
altitude alert system will test the complete system.



Your response dated 10 July 2000 to the ATSB recommendation IR
19990150 states that;



"...RAC has reviewed the B200 Maintenance Manual Procedures for
Functional Test Procedure of the Oxygen Auto-deploy
System...".



ATSB recommendation IR 19990150 was issued with respect to
Beechcraft aircraft but your response addresses the B200 type. Has
Raytheon addressed other Beechcraft aircraft types that may have
automatically deployable passenger oxygen activation systems and
cabin altitude alert systems? If so, could you please provide the
results of the review/s and the relevant section/s of the amended
maintenance manual/s?



On receipt of evidence to show that the recommendation has been
addressed to cover these questions, we will review our
classification.