Continental Airlines

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.