# 2026-15978: FAA frets over vintage chopper rotors in lift ops.

2026-15978, Airworthiness Directives; Various Helicopters, is a Federal Register rule from Transportation Department, Federal Aviation Administration published 2026-08-06, effective 2026-09-10; PRIA reads it as touching household money (as of 2026-08-13).

- Canonical: https://policyrisk.com/federal-register/2026-15978
- As of: 2026-08-13
- Plain-text twin of the page above; the HTML and this file carry the same facts.

## Facts
- Document number: 2026-15978
- Title: Airworthiness Directives; Various Helicopters
- Type: Rule
- Agencies: Transportation Department; Federal Aviation Administration
- Citation: 91 FR 50696
- Published: 2026-08-06
- Effective: 2026-09-10
- Comments close: not stated
- Significant: no
- Touches household money: yes
- Regulation identifier numbers: 2120-AA64
- Last updated: 2026-08-13

## In one line

FAA frets over vintage chopper rotors in lift ops.

## Summary

The FAA is superseding Airworthiness Directive (AD) 2015-20-12 for certain Sikorsky Aircraft Corporation Model S-61A, D, E, L, N, NM, R, and V; Croman Corporation Model SH-3H; Carson Helicopters, Inc., Model S-61L and SH-3H; Glacier Helicopter, 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. AD 2015-20-12 required performing calculations to determine whether the main rotor shaft (MRS) was used in repetitive external lift (REL) operations or non-REL operations, performing a nondestructive inspection (NDI) of the REL MRS for cracks and, depending on the results of the NDI, replacing the MRS, marking any REL MRS at the time of the NDI, establishing retirement lives for each REL MRS, and removing from service any MRS with oversized dowel pin bores. Since the FAA issued AD 2015-20-12, a design re-evaluation shows that the MRS on certain helicopter models requires a lower life limit. This AD retains some of the requirements of AD 2015-20-12, and also reduces the retirement life for a certain MRS installed on certain helicopters and updates the type certificate holder name for some of the affected helicopter models. The FAA is issuing this AD to address the unsafe condition on these products.

## Effects PRIA read

- Non-REL Main Rotor Shaft Life Cut: cost, high. If you operate an affected helicopter, the retirement life for a Non-Repetitive External Lift (Non-REL) main rotor shaft (MRS) is reduced from 13,000 hours time-in-service (TIS) to 7,300 hours TIS. If an MRS has 7,300 hours TIS or more as of the AD effective date, remove it from service (if install…
- Mandatory Inspections, Marking, and Recordkeeping: cost, medium. Operators must perform calculations to classify each MRS as REL or Non-REL (first calculation within 250 hours TIS) and keep a component history card. Within 1,100 hours TIS after November 24, 2015, perform a nondestructive inspection (NDI) for cracks on each MRS, mark REL shafts with 'REL', and re…
- Immediate Removal for Oversized Dowel Pin Bores: cost, high. Any MRS with oversized dowel pin bores (0.8860 inches diameter or greater) must be removed from service within 50 hours TIS after November 24, 2015. Removing and replacing an MRS is estimated at about $81,471 per product in the FAA cost table.

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## Sources
- [2026-15978 on federalregister.gov](https://www.federalregister.gov/documents/2026/08/06/2026-15978/airworthiness-directives-various-helicopters)
- [2026-15978 as published (PDF)](https://www.govinfo.gov/content/pkg/FR-2026-08-06/pdf/2026-15978.pdf)

## Related
- [Previous: 2026-15970, Safety Zone; Lake Erie, Madison Township, OH](https://policyrisk.com/federal-register/2026-15970)
- [Next: 2026-15984, Alaska: Final Authorization of State Hazardous Waste Program](https://policyrisk.com/federal-register/2026-15984)
- [All Federal Register documents](https://policyrisk.com/federal-register)

Source: PRIA, https://policyrisk.com/federal-register/2026-15978 (as of 2026-08-13).