Continental Airlines Systems Engineering has reviewed the reference /A/ NPRM
and object to this proposed rule with the following comments:
1. Boeing has stated that the reason for the release of reference /B/
Service Bulletin is due to its concern regarding shop process deficiencies at some
repair facilities where correct overhaul procedures were not followed. Continental
Airlines finds this reasoning to be detrimental to all operators that follow correct
overhaul procedures at their repair facilities. Continental Airlines landing gear
components, including the left and right main landing gear retract actuator beam
are time controlled per reference /C/ and are scheduled to be overhauled at an
interval of every 10 years at a FAA-approved landing gear overhaul facility.
2. Paragraph (f) of reference /A/ NPRM requires overhaul of the left and
right main landing gear retract actuator beam in accordance with reference /B/
Service Bulletin. The accomplishment instructions for the overhaul of the left and
right main landing gear retract actuator beam in the reference /B/ Service Bulletin
have the following requirements that Continental Airlines finds objectionable:
a. Step (4) of Figure 2 of reference /B/ Service Bulletin requires that all
chrome and nickel on the actuator beam be stripped. Continental Airlines finds
this step to be unnecessary as an operator is now being mandated to strip
chrome and nickel plating from the landing gear retract actuator beam that could
have no visible signs of distress. Continental Airlines recommends that the
stripping of all chrome and nickel plating be an option as in CMM 32-00-05
b. Step (9) of Figure 2 of reference /B/ Service Bulletin requires a nital
etch inspection of machined surfaces only. Continental Airlines proposes that the
nital etch inspection be extended to the entire actuator beam as there is a
possibility of induced burns or heat damage that would not be discovered if the
nital etch was limited to machined surfaces only.
c. Step (10) of Figure 2 of reference /B/ Service Bulletin requires stress
relieving the part for 4 hours at 525°F. Continental Airlines is of the opinion that
since this step would relieve all stresses, it would be better to use an optional
step in SOPM 20-10-02 and stress relieve the part for 4 hours at 350-400°F.
d. Step (12) of Figure 2 of reference /B/ Service Bulletin requires shot
peening the entire part. Continental Airlines recommends that the shot peen
process be limited to only the machined areas of the part since the geometry of
the actuator beam does not allow for effective shot peening of the entire area.
e. Step (13) of Figure 2 of reference /B/ Service Bulletin has no caution
note similar to Step (14) of Figure 2 of reference /B/ Service Bulletin that requires
inspection for arc burns associated with grounding, racks or holding fixtures or
surfaces adjacent to anodes.
Based on the comments above, Continental Airlines requests that the following
changes be made to reference /A/ NPRM:
1. Paragraph (f) of reference /A/ NPRM be revised to not mandate the
instructions for overhaul of the left and right main landing gear retract actuator
beam in accordance with reference /B/ Service Bulletin.
Continental Airlines
This is comment on Rule
Airworthiness Directives; Boeing Model 737-100, -200, -200C, - 300, -400, and -500 Series Airplanes
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Continental Airlines
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Continental Airlines
Related Comments
Public Submission Posted: 11/13/2008 ID: FAA-2008-1070-0003
Nov 24,2008 11:59 PM ET
Public Submission Posted: 11/24/2008 ID: FAA-2008-1070-0004
Nov 24,2008 11:59 PM ET