Proposed Rule on Main Driveshaft

Posted by the Federal Aviation Administration on Mar 25, 2021

FAA Site link for this NPRM HERE

Action Notice of proposed rulemaking (NPRM). Summary The FAA proposes to adopt a new airworthiness directive (AD) for type certificated Model UH-1H restricted category helicopters. This proposed AD was prompted by multiple reports of failure of the main driveshaft. This proposed AD would require establishing a life limit for certain main driveshafts, and a one-time and repetitive inspections of the main driveshafts. The FAA is proposing this AD to address the unsafe condition on these products. Dates The FAA must receive comments on this proposed AD by May 10, 2021. Addresses You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

Federal eRulemaking Portal: Go to Follow the instructions for submitting comments.

  • Fax: (202) 493-2251.

  • Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

  • Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, contact Army Publishing Directorate, 9301 Chapek Rd., Bldg 1458, Fort Belvoir, VA 22060-5447; telephone (703) 614-3727; email; or at

You may also contact the following as applicable: Arrow Falcon Exporters Inc., 2081 S Wildcat Way, Porterville, CA 93257; telephone (559) 781-8604; fax (559) 781-9271; email Global Helicopter Technology, Inc., P.O. Box 180681, Arlington, Texas 76096; telephone (817) 557-3391; email Hagglund Helicopters, LLC, 5101 NW A Avenue, Pendleton, OR 97801; telephone (800) 882-3554 or (541) 276-3554; fax (541) 276-1597. JASPP Engineering Services, LLC., 511 Harmon Terrace, Arlington, TX 76010; telephone (817) 465-4495; or at Northwest Rotorcraft, LLC, 1000 85th Ave. SE, Olympia, WA 98501; telephone (360) 754-7200; or at Overseas Aircraft Support, Inc., P.O. Box 898, Lakeside, AZ 85929; telephone (928) 368-6965; fax (928) 368-6962. Richards Heavylift Helo, Inc., 1181 Osprey Nest Point, Orange Park, FL 32073; (904) 472-1481; email Rotorcraft Development Corporation, P.O. Box 430, Corvallis, MT 59828; telephone (207) 329-2518; email Southwest Florida Aviation International, Inc., 28000-A9 Airport Road, Bldg. 101, Punta Gorda, FL 33982-9587; telephone (941) 637-1161; fax (941) 637-6264; email Tamarack Helicopters, Inc., 2849 McIntyre Rd., Stevensville, MT 59870; telephone (406) 777-0144; or at

You may view this service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. Examining the AD Docket You may examine the AD docket at by searching for and locating Docket No. FAA-2021-0189; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, any comments received, and other information. The street address for Docket Operations is listed above. For Further Information Contact Matthew L. Thompson, Aerospace Engineer, DSCO Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5251; email

Supplementary Information Comments Invited The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2021-0189; Project Identifier AD-2020-00645-R” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this proposal because of those comments. Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to, including any personal information you provide. The a