# AD 77-10-12: Crank Arm Assembly

- Type: Airworthiness directive
- Status: Current
- Products: Boeing DC-8-11, DC-8-12, DC-8-21, DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, DC-8-43, DC-8-51, DC-8-52, DC-8-53 and 15 more
- Effective: May 26, 1977
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-2906
- Registered aircraft: 8 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/21B07952F3B3846D862569CA004A83AF.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/77-10-12

## The airworthiness directive

77-10-12 MCDONNELL DOUGLAS: Amendment 39-2906. Applies to Model DC-8 Series airplanes, certificated in all categories.

Compliance required within the next 300 hours time in service or 30 days after the effective date of this AD, whichever comes first, unless already accomplished within the past 30 days.

To detect cracks and prevent failure or jamming of the elevator geared tab crank arm and gust lock assemblies, comply with the following:

  (a) Visually inspect both the left and right side inboard and outboard elevator geared tab crank arm assemblies, P/N's 4710541 and 4710542 for failure and/or cracks.

  (b) Visually inspect the P/N 5644178 gust lock assembly, and specifically, the torque tube section of the P/N 4644181 crank assembly, for failure and/or cracks.

  (c) Failed or cracked parts must be replaced with like serviceable parts before further flight.

  (d) Verify that clearance exists between the crank assemblies, P/N 4710541 and 4710542, and the boxsection for all positions along elevator travel.

Note: McDonnell Douglas DC-8 Alert Service Bulletin A27-262, dated April 28, 1977, covers the same subject.

  (e) Special flight permits may be issued in accordance with FAR's 21.197 and 21.199 to authorize operation of an airplane to a base to perform the inspections required by this AD.

This amendment becomes effective May 26, 1977.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 4A25](https://openairdocs.org/tcds/4A25): The Boeing Company; names 27 of 27 models: DC-8-41, DC-8-52, DC-8-61, DC-8-53, DC-8-51, DC-8-63, DC-8-11, DC-8-72F…

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 8 (8 by airframe model, 0 by engine model)
- Makers: Douglas 5, Mcdonnell Douglas 3

Models with the most aircraft:

- [Douglas DC-8-73](https://openairdocs.org/model/douglas-dc-8-73): 2 aircraft (airframe model)
- [Douglas DC-8-73F](https://openairdocs.org/model/douglas-dc-8-73f): 2 aircraft (airframe model)
- [Mcdonnell Douglas DC-8-62](https://openairdocs.org/model/mcdonnell-douglas-dc-8-62): 1 aircraft (airframe model)
- [Mcdonnell Douglas DC-8-63](https://openairdocs.org/model/mcdonnell-douglas-dc-8-63): 1 aircraft (airframe model)
- [Mcdonnell Douglas DC-8-63F](https://openairdocs.org/model/mcdonnell-douglas-dc-8-63f): 1 aircraft (airframe model)
- [Douglas DC-8-72](https://openairdocs.org/model/douglas-dc-8-72): 1 aircraft (airframe model)

All 6 models: https://openairdocs.org/ad/77-10-12/models.md
Every aircraft: https://openairdocs.org/ad/77-10-12/aircraft.md

Its text cites no advisory circulars or STCs.

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