Federal Aviation Administration July 25, 2012 – Federal Register Recent Federal Regulation Documents

Airworthiness Directives; Turbomeca S.A. Turboshaft Engines
Document Number: 2012-18155
Type: Proposed Rule
Date: 2012-07-25
Agency: Federal Aviation Administration, Department of Transportation
We propose to supersede an existing airworthiness directive (AD) that applies to all Turbomeca S.A. Arriel 1A, 1A1, 1A2, 1B, 1C, 1C1, 1C2, 1D, 1D1, 1E, 1E2, 1K, 1K1, 1S, and 1S1 turboshaft engines. The existing AD currently requires initial and repetitive visual inspections for erosion caused by dust ingestion and, if necessary, cleaning of the gas generator (module M03). Since we issued that AD, in-service experience has shown that dust inside the gas generator hollow shaft may be found when the axial compressor wheel has less erosion than initially assessed. This proposed AD would require determining the engine history, a one-time visual inspection of the axial compressor for erosion, initial and repetitive cleaning of the gas generator hollow shaft, and replacement of the rear bearing if the amount of dust collected during cleaning exceeds 8 grams. This proposed AD also includes an optional terminating action. We are proposing this AD to prevent an unbalance of the gas generator rotating assembly, which may lead to gas generator rear bearing failure, and uncommanded engine shutdown.
Airworthiness Directives; The Boeing Company Airplanes
Document Number: 2012-18147
Type: Proposed Rule
Date: 2012-07-25
Agency: Federal Aviation Administration, Department of Transportation
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 737-600, -700, -700C, -800, and -900 series airplanes. This proposed AD was prompted by a report of cracks found in the skin at body station (STA) 540 just below stringer S-22L on a Model 737-700 series airplane. This proposed AD would require repetitive detailed and high frequency eddy current inspections for cracking of the skin around the eight fasteners common to the ends of the STA 540 bulkhead chords between stringers S-22 and S-23, left and right sides; and corrective actions and preventive modification if necessary. We are proposing this AD to detect and correct fatigue cracking in the skin, which can result in rapid decompression of the cabin.
Airworthiness Directives; Bombardier, Inc. Airplanes
Document Number: 2012-18145
Type: Proposed Rule
Date: 2012-07-25
Agency: Federal Aviation Administration, Department of Transportation
We propose to supersede an existing airworthiness directive (AD) that applies to certain Bombardier, Inc. Model DHC-8-400 series airplanes. The existing AD currently requires a modification to trim the edge of the bumper plate, including performing an inspection for damage or cracks of the bumper plate and base fitting, and replacing any damaged or cracked part. That AD also currently requires, for certain airplanes, reidentifying the bumper plate. Since we issued that AD, we have determined that an operational check must be done after reidentifying the bumper plate to ensure the identified unsafe condition is addressed. This proposed AD would require, for airplanes on which the reidentification is done, an operational check of the alternate extension system of the main landing gear (MLG), and repair if necessary. We are proposing this AD to detect and correct failure of the MLG to extend and lock, which could adversely affect the safe landing of the airplane.
Airworthiness Directives; Turbomeca S.A. Turboshaft Engines
Document Number: 2012-18050
Type: Proposed Rule
Date: 2012-07-25
Agency: Federal Aviation Administration, Department of Transportation
We propose to supersede an existing airworthiness directive (AD) that applies to all Turbomeca S.A. Arriel 1E2, 1S, and 1S1 turboshaft engines. The existing AD currently requires a one time inspection and torque check of a certain 3-way union plug installed on all fuel control units (FCUs). Since we issued that AD, the applicability has been reduced to certain FCUs and the referenced service bulletin has been updated with additional detailed information to identify the non-compliant ``red disk'' plug. This proposed AD would still require a one time inspection and torque check of the 3-way union plug, would require replacement of the plug before further flight if it is found to be non-compliant, and would prohibit installation of FCUs that have not passed the 3-way union plug inspection and torque check. We are proposing this AD to prevent fuel leaks, which could result in a fire and damage to the helicopter.