AD 2020-02-17

Recurring final rule
Data completeness: 80%

Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

AD Number
2020-02-17
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2019-0663
FR Citation
85 FR 7191

Applicability

TypeManufacturerModelDetails
aircraft Sikorsky Aircraft Corporation Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Unsafe Condition

Disbonding between the tail rotor (T/R) blade pitch horn and the torque tube, if not addressed, could result in increased T/R vibrations, physical failure of the torque tube, and subsequent loss of control of the helicopter.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Visually inspect each T/R blade for a crack, leading edge erosion, and trailing edge skin disbonding and separation, paying particular attention to the area from the midspan to the pitch control horn. If there is a crack, any leading edge erosion, trailing edge disbonding, or trailing edge separation, before further flight, replace the T/R blade with an airworthy part. Tap test inspect each T/R blade for disbonding in the pitch horn to torque tube bond area. If there is any disbonding, before further flight, replace the T/R blade with an airworthy part.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Before the first flight of each day

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Affected Aircraft

Model S-70, S-70A, S-70C, S-70C(M), and S-70C(M1) helicopters, certificated in any category, with a tail rotor (T/R) blade part number 70101-31000 (all dash numbers) with a serial number (S/N) up to and including A009-08915.

AI-generated summary from the source AD text. Verify against the official source before acting.

Source: Official FAA Source ↗

Retrieved: Apr 4, 2026

Rights: U.S. Government Public Domain

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