Airworthiness Directive · Amendment 39-9225 · Arrow Falcon Exporters, Inc., AST, Inc, Bell Helicopter Textron, Inc., California Department of Forestry, Global Helicopter Technology, Inc., Hagglund Helicopters, LLC, International Helicopters, Inc., Overseas Aircraft Support Inc, Richards Heavylift Helo, Inc., Robinson Air Crane, Inc., Rotorcraft Development Corporation, San Joaquin Helicopters, Smith Helicopters, Sout
Arrow Falcon Exporters, Inc., AST, Inc, Bell Helicopter Textron, Inc., California Department of Forestry, Global Helicopter Technology, Inc., Hagglund Helicopters, LLC, International Helicopters, Inc., Overseas Aircraft Support Inc, Richards Heavylift Helo, Inc., Robinson Air Crane, Inc., Rotorcraft Development Corporation, San Joaquin Helicopters, Smith Helicopters, Sout
This AD applies to Arrow Falcon Exporters, Inc., AST, Inc, Bell Helicopter Textron, Inc., California Department of Forestry, Global Helicopter Technology, Inc., Hagglund Helicopters, LLC, International Helicopters, Inc., Overseas Aircraft Support Inc, Richards Heavylift Helo, Inc., Robinson Air Crane, Inc., Rotorcraft Development Corporation, San Joaquin Helicopters, Smith Helicopters, Southern Helicopter, Inc., Southwest Florida Aviation International, Tamarack Helicopters, Inc., West Coast Fabrications UH-1H, UH-1F, TH-1L, UH-1E, UH-1L, UH-1B, UH-1A, TH-1F, UH-1P.
The models as the FAA's AD index lists them. The serial ranges, installed parts and exceptions are in the AD itself: read it at the FAA.
This amendment adopts a new airworthiness directive (AD) that is applicable to Bell Helicopter Textron, Inc. (BHTI)-manufactured restricted category Model UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, UH-1P, TH-1F, and TH-1L helicopters. This action requires verification that the tail rotor control system is rigged in accordance with the applicable maintenance manual; a fluorescent penetrant inspection for cracks at the roots of the gear teeth on the pinion and gear of affected 42-degree tail rotor drive gearbox assemblies (42-degree gearboxes), and replacement of the 42-degree gearbox pinion or gear if cracks are found; and, creation of a component history card to track numbers of torque events. A torque event is defined as a takeoff or a lift (internal or external). This amendment is prompted by 14 accidents reported since 1979 in the United States and Canada related to failure of the 42-degree gearbox. The actions specified in this AD are intended to prevent failure of the 42-degree gearbox, loss of tail rotor control, and subsequent loss of control of the helicopter.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
