Airworthiness Directives; Robinson Helicopter Company (Robinson)
We propose to adopt a new airworthiness directive (AD) for Model R22, R22 Alpha, R22 Beta, and R22 Mariner helicopters with certain fuel shut-off valves installed. This proposed AD would require replacing the fuel shut-off valve with a newer design fuel shut-off valve. This proposed AD is prompted by three accidents that occurred because the fuel shut-off valve was inadvertently moved to the ``off'' position. The proposed actions are intended to prevent inadvertent closing of the fuel valve, which could result in engine power loss and subsequent loss of control of the helicopter.
Airworthiness Directives; Various Sikorsky-Manufactured Transport and Restricted Category Helicopters
We are revising the proposals in an earlier notice of proposed rulemaking (NPRM) for certain Sikorsky Aircraft Corporation (Sikorsky) Model S-61A, D, E, L, N, NM (serial number 61454), R, and V; Croman Corporation Model SH-3H, Carson Helicopters, Inc., Model S-61L; Glacier Helicopters, Inc. Model CH-3E; Robinson Air Crane, Inc. Model CH-3E, CH-3C, HH-3C, and HH-3E; and Siller Helicopters Model CH-3E and SH-3A helicopters. The NPRM proposed superseding an existing AD but retaining some requirements of that AD, removing certain dowel pin bores, expanding the applicability to include additional helicopters, and implementing a new retirement life for each main rotor shaft (MRS) based on a reevaluation of the MRS service life. This SNPRM is prompted by the comments received in response to the NPRM and a reevaluation of the relevant data. The proposed actions are intended to prevent MRS structural failure, loss of power to the main rotor, and subsequent loss of control of the helicopter.
Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell) Model Helicopters
We propose to supersede an existing revised airworthiness directive (AD) for all Bell Model 204B and certain serial-numbered Model 205A-1 helicopters with a certain tail rotor pitch control chain (chain) installed. The existing AD requires visually inspecting the chain to detect a crack in the link segments and, for affected Model 205A-1 helicopters, replacing the tail rotor chain and cable control system with a push-pull control system. Since we issued that AD, we have determined the need to apply the requirements to a newly-produced, similarly-designed chain with a different part number. Also, for the Model 204B, data shows the need to reduce the inspection interval of the chain and revise its inspection procedures because the rapid growth of a crack can lead to premature chain failure and to install a tail rotor cable and chain damper kit (damper kit) to reduce the oscillatory loading. We have also determined that installing a push-pull control system should apply to Model 205A-1 helicopters with certain serial numbers, regardless of the chain part number installed. These proposed actions are intended to prevent failure of the chain, loss of tail rotor blade pitch control, and subsequent loss of control of the helicopter.
Airworthiness Directives; AgustaWestland S.p.A. Helicopters
We propose to adopt a new airworthiness directive (AD) for AgustaWestland S.p.A. (AgustaWestland) Model A119 and AW119 MKII helicopters to require inspecting the pilot and co-pilot doors to ensure that the windows are properly bonded within the doors. If the windows are not properly bonded, the proposed AD would require applying bonding to the windows, the seals, and the window frames of the pilot and co-pilot doors. This proposed AD is prompted by the loss of a pilot-door window during a test flight. The proposed actions are intended to ensure the windows do not detach from the doors, potentially injuring persons on the ground and damaging the helicopter's tailboom and the tail rotor blades.
Modification of VOR Federal Airway V-595, Oregon
This action modifies VHF omnidirectional range (VOR) Federal airway V-595 in Oregon due to the scheduled decommissioning of the Portland, OR, VOR/DME navigation aid, which currently serves as an end point for the route.
Airworthiness Directives; Cessna Aircraft Company Airplanes
We are adopting a new airworthiness directive (AD) for certain Cessna Aircraft Company (Cessna) Model 525 airplanes equipped with certain part number (P/N) air conditioning (A/C) compressor motors. This AD was prompted by reports of smoke and/or fire in the tailcone caused by brushes wearing beyond their limits on the A/C motor. This AD requires inspection of the number of hours on the A/C compressor hour meter, inspection of the logbook, replacement of the brushes on certain P/N A/C compressor motors or deactivation of the A/C system until replacement of the brushes, and reporting of airplane information related to the replacement of the brushes. We are issuing this AD to correct the unsafe condition on these products.
Airworthiness Directives; The Boeing Company Airplanes
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-900 and -900ER series airplanes. This AD was prompted by reports of early fatigue cracks at chem-mill areas on the crown skin panels. This AD requires repetitive inspections for cracking of the fuselage skin along chem-mill steps at certain crown skin and shear wrinkle areas, and repair if necessary. We are issuing this AD to detect and correct fatigue cracking of the skin panel at the specified chem-mill step locations, which could result in rapid decompression of the airplane.
Airworthiness Directives; Kelowna Flightcraft R & D Ltd. Airplanes
We are adopting a new airworthiness directive (AD) for certain Tracor (Convair) Model 340 and 440 airplanes and certain Military Model C-131B, C-131D, C-131E, and C131F/R4Y-1 airplanes. This AD requires repetitive inspections of the lower skin of the wings for cracking around the inboard side of the wing station (WS) 6 and 7 access panel doubler fingers and between stringers 5 and 11; repetitive inspections of the lower skin of the wings for cracking around stringers 6, 8, and 10, and around the WS 6 and WS 7 access panel doubler fingers; and repair if necessary. This AD was prompted by a report of a crack found on the lower skin of the right-hand wing between WS 5 and WS 6. We are issuing this AD to detect and correct fatigue cracking of the lower skin of the wings, which could result in reduced structural integrity of the wings.