曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
the time of manufacture of the said valve.
5. MATTERS FOR REFERENCE
5.1 Response of the Safety Valve’s Manufacturer
(1) Corrective Measures taken related to the production of safety valves after 1998
Of the safety valves repaired since 1998, inspection when the valves were accepted
for repair found that 40% operated at a greater positive differential pressure than
the limit specified in the CMM. This necessitated remedial action from the point of
view of protection of aircraft structures, and as a result the following corrective
measures had been planned by March 2001:
Improvements to the production process
a. Adjustment of the operating point
(a) Reduction of the rate of pressure change
(b) Carrying out of the adjustment process at least three times
b. Improvements at the time of control valve assembly
(a) Implementation of the stem poppet drop test (inspection to confirm
that the stem poppet enters the bush hole of the seat assembly
smoothly by dropping the stem poppet into the bush hole from the
opposite direction).
(b) 100% inspection of the stem assembly spring load.
(c) To ensure that no burrs remain after drilling, implementation of
supplier auditing, an additional cleaning process at the safety valve
manufacturer, and 100% inspection of key dimensions.
(d) Total inspection for stem poppet straightness (no bending).
(e) Implementation of control valve leakage test.
(f) Training of personnel in correct shim adjustment.
Improvement of CMM
a. Designation of the stem assembly as a non-repairable part.
b. Revision of the CMM, reflecting to make the production process consistent
with the method of adjusting the operating point of the valve.
(2) Corrective Measures following this incident investigation
As a result of the additional safety valve investigations carried out in this serious
incident investigation, a revised CMM reflecting the following contents was issued
on March 13, 2002.
Establishment of a minimum limit for adjustment screw protrusion.
Execution of the Positive Relief Test at least three times to verify the set value.
Also establishment of its tolerances of the lower and upper limits.
Supplement paragraphs relating to troubleshooting tests with confirmation of
motion of the stem poppet and with leakage tests of the stem assembly and the
control valve.
5.2 Response of the Aircraft Manufacturer
The AMM was revised on May 1, 2002, such that a Relief Test of the safety valves is also
carried out three or more times with the valves installed in the aircraft.
5.3 Response of the ARS
(1) Based on an “Engineering Order” issued by the said company, the work sheet for
repair was revised to specify that the Relief Test be repeated at least three times to
verify no scatter of the calibrated value.
(2) The revised contents of the CMM as described in section 5.1 (2) were reflected to the work
sheet on June 12, 2002.
5.4 Response of the said Aircraft Operator
(1) Provisional Measures
Relief Tests were conducted on the safety valves installed on Airbus A320-200 and
A321-131 aircraft belonged to said aircraft operator.
(2) Permanent Measures
The stem assemblies of the safety valves installed in all Airbus A320-200 and
A321-131 aircraft belonging to the said aircraft operator were replaced with ones
manufactured on and after May 2001 and that incorporated the manufacturing
improvements, and at the same time, the shim thickness of a stem assembly was
verified and corrected as necessary.
22
Figure1 Three views
Unit
11.8
33.9
37.6
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