# AD 85-25-05: Self-Locking Nuts

- Type: Airworthiness directive
- Status: Current
- Products: Boeing 757-200 Series
- Effective: December 21, 1985
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-5178
- Registered aircraft: 243 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/0F4297F04523253E862568AA0065A39C.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/85-25-05

## The airworthiness directive

85-25-05 BOEING: Amendment 39-5178. Applies to Model 757-200 series airplanes listed in Boeing Service Bulletin 757-27-0069, dated November 4, 1985. To detect nuts installed in the aileron, rudder and elevator power control actuators, and rudder ratio changer that have insufficient self-locking torque characteristics, accomplish the following, unless already accomplished:

A. Within 30 days after the effective date of this AD, check the self-locking nuts, P/N BACN10JC12CM or BACN10JC12CD, for proper self-locking torque in accordance with Paragraph III of Boeing Service Bulletin 757-27-0069, dated November 4, 1985, or later FAA- approved revision. If any self-locking nut is found not to meet the self-locking torque requirements of Boeing Service Bulletin 757-27-0069, dated November 4, 1985, or later FAA- approved revision, replace it prior to further flight with a nut found to meet the self-locking torque requirements of the above referenced service bulletin.

B. Alternate means of compliance which provide an acceptable level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD.

All persons affected by this document who have not already received copies of the service bulletin may obtain copies upon request from the Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.

This amendment becomes effective December 21, 1985.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A2NM](https://openairdocs.org/tcds/A2NM): The Boeing Company; names 1 of 4 models: 757-200 Series

## 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: 243 (243 by airframe model, 0 by engine model)
- Makers: Boeing 243

Models with the most aircraft:

- [Boeing 757-232](https://openairdocs.org/model/boeing-757-232): 63 aircraft (airframe model)
- [Boeing 757-224](https://openairdocs.org/model/boeing-757-224): 40 aircraft (airframe model)
- [Boeing 757-222](https://openairdocs.org/model/boeing-757-222): 38 aircraft (airframe model)
- [Boeing 757-223](https://openairdocs.org/model/boeing-757-223): 23 aircraft (airframe model)
- [Boeing 757-236](https://openairdocs.org/model/boeing-757-236): 20 aircraft (airframe model)
- [Boeing 757-251](https://openairdocs.org/model/boeing-757-251): 18 aircraft (airframe model)
- [Boeing 757-231](https://openairdocs.org/model/boeing-757-231): 13 aircraft (airframe model)
- [Boeing 757-200 SERIES](https://openairdocs.org/model/boeing-757-200-series): 7 aircraft (airframe model)
- [Boeing 757-204](https://openairdocs.org/model/boeing-757-204): 6 aircraft (airframe model)
- [Boeing 757-225](https://openairdocs.org/model/boeing-757-225): 5 aircraft (airframe model)
- [Boeing 757-230](https://openairdocs.org/model/boeing-757-230): 4 aircraft (airframe model)
- [Boeing 757-258](https://openairdocs.org/model/boeing-757-258): 3 aircraft (airframe model)
- [Boeing 757-256](https://openairdocs.org/model/boeing-757-256): 3 aircraft (airframe model)

All 13 models: https://openairdocs.org/ad/85-25-05/models.md
Every aircraft: https://openairdocs.org/ad/85-25-05/aircraft.md

Its text cites no advisory circulars or STCs.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.