The FAA is adopting a new airworthiness directive (AD) for certain type certificated Model UH-1H restricted category helicopters. This AD was prompted by multiple reports of failure of the main driveshaft. This AD requires establishing a limit to replace certain main driveshafts and a one-time and repetitive inspections of the main driveshafts. NAAA reported on the proposed AD in the April 8, 2021 NAAA eNewsletter.
The AD may require action before further flight after its effective date. This AD is effective Feb. 25. The entire AD is available here.