# AD 86-20-05: Cowl Doors and Pylon Brackets

- Type: Airworthiness directive
- Status: Current
- Products: Boeing 707-300 Series, 707-300B Series and 707-300C Series with STC SA2699NM
- Effective: October 13, 1986
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-5426
- Registered aircraft: 6 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C86403C117ADF6E6862568AA006B4020.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/86-20-05

## The airworthiness directive

86-20-05 BOEING: Amendment 39-5426. Applies to Boeing Model 707-300 series airplanes modified in accordance with Supplemental Type Certificate (STC) SA2699NM, certificated in any category. Compliance required as indicated, unless previously accomplished.

To prevent loss of engine core cowl door, within 150 hours time in service, or within 30 days, whichever occurs earlier after the effective date of this AD, accomplish the following:

A. Modify the core cowl doors and pylon support brackets in accordance with Tracor Aviation Alert Service Bulletins AQ707-71-006, Revision 1, dated February 18, 1986; AQ707-71-012, Revision 1, dated September 5, 1986; AQ707-71-013, dated September 4, 1986; and Tracor Aviation Service Bulletins Q707-71-007, dated March 7, 1986; Q707-71-009, Revision 1, dated July 9, 1986; Q707-71-010, dated May 30, 1986; or later FAA-approved revisions.

B. Alternate means of compliance which provide an acceptable level of safety may be used when approved by the Manager, Los Angeles 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 in order to comply with the requirements of this AD.

All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Tracor Aviation, Inc., 495 South Fairview Avenue, Goleta, California 93117, Attention: Customer Services. These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Los Angeles Aircraft Certification Office, 4344 Donald Douglas Drive, Long Beach, California.

This amendment becomes effective October 13, 1986.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 4A26](https://openairdocs.org/tcds/4A26): The Boeing Company; names 3 of 4 models: 707-300B Series, 707-300 Series, 707-300C 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: 6 (6 by airframe model, 0 by engine model)
- Makers: Boeing 6

Models with the most aircraft:

- [Boeing 707-338C](https://openairdocs.org/model/boeing-707-338c): 2 aircraft (airframe model)
- [Boeing 707-368C](https://openairdocs.org/model/boeing-707-368c): 1 aircraft (airframe model)
- [Boeing 707-321B](https://openairdocs.org/model/boeing-707-321b): 1 aircraft (airframe model)
- [Boeing 707-323B](https://openairdocs.org/model/boeing-707-323b): 1 aircraft (airframe model)
- [Boeing 707-351B](https://openairdocs.org/model/boeing-707-351b): 1 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/86-20-05/models.md
Every aircraft: https://openairdocs.org/ad/86-20-05/aircraft.md

## Related documents

- [STC SA2699NM](https://openairdocs.org/stc/SA2699NM): Modification of the Boeing Model 707-300B (advanced) and 707-300C airplanes.. Omega Aviation Services Ltd, Named in the applicability

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