# AD 64-25-01: Cowl Panel and Aft Thrust Reverser Sleeve

- Type: Airworthiness directive
- Status: Current
- Products: Boeing 707-100 Long Body, 707-100B Long Body, 707-100B Short Body, 707-200, 707-300 Series, 707-300B Series, 707-300C Series, 707-400 Series, 720 Series and 720B Series
- Effective: December 7, 1964
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-1
- Registered aircraft: 6 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CB9569309C2597658625682E00517D1D.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/64-25-01

## The airworthiness directive

64-25-01 BOEING: Amdt. 39-1 Part 507 Federal Register November 6, 1964. Applies to Models 707 and 720 Series Aircraft Equipped With Pratt & Whitney JT3D Engines.

Compliance required as indicated.

There have been a number of engine fires in service due to fuel accumulation in the aft thrust reverser sleeve and the side cowl panel as a result of false starts.

To correct this condition, unless already accomplished, provide additional fluid drainage in the left-hand side cowl panel and aft thrust reverser sleeve on each engine in accordance with either (a) or (b) or an equivalent approved by the Aircraft Engineering Division, FAA Western Region.

  (a) Within 3,100 hours' time in service after the effective date of this AD accomplish the following:

  (1) Drill or cut four 1/2 inch-diameter holes through lower skin of the aft thrust reverser sleeve at Station 222.30 as shown on page 5 of Boeing Service Bulletin No. 1908.

  (2) Drill or cut two 1/4 inch-diameterholes through lower skin of aft thrust reverser sleeve at Station 222.30, one hole outboard of each channel section E-E and F-F at the locations shown on page 6 of Boeing Service Bulletin No. 1908.

  (3) Drill or cut two 1/2-inch diameter holes through lower skin of the aft thrust reverser sleeve at Station 241.75 as shown on page 4 of Boeing Service Bulletin No. 1908.

  (4) Drill or cut two 1/4 inch-diameter holes, one hole outboard of each rib, through lower skin on the aft thrust reverser sleeve, 1.3 inches outboard and 0.1 inch forward of each hole drilled in accordance with (a)(3).

  (5) Drill or cut two 1/2 inch-diameter holes through lower skin on left-hand side cowl nacelle Station 197.51 and bend trailing edge of each hole as shown on page 8 of Boeing Service Bulletin No. 1908.

  (b) Within 3,100 hours' time in service after the effective date of this AD, drill or cut additional 1/2 inch-diameter drain holes in the aft thrust reverser sleeve and in the left sidecowl panel in accordance with Boeing Service Bulletin No. 1908.

NOTE. - American Airlines, Inc. Fleet Campaign Directive No. 810B is an equivalent which has been approved by the Aircraft Engineering Division, FAA Western Region.

(Boeing Service Bulletin No. 1908 dated January 16, 1964, covers this same subject.)

This directive effective December 7, 1964.

## Affected data sheets (3) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 4A21](https://openairdocs.org/tcds/4A21): The Boeing Company; names 4 of 4 models: 707-100B Short Body, 707-200, 707-100 Long Body, 707-100B Long Body
- [TCDS 4A26](https://openairdocs.org/tcds/4A26): The Boeing Company; names 4 of 4 models: 707-300B Series, 707-400 Series, 707-300 Series, 707-300C Series
- [TCDS 4A28](https://openairdocs.org/tcds/4A28): The Boeing Company; names 2 of 2 models: 720B Series, 720 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/64-25-01/models.md
Every aircraft: https://openairdocs.org/ad/64-25-01/aircraft.md

Its text cites no advisory circulars or STCs.

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