# AD 59-17-02: Purolator Filter

- 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 and 707-400 Series
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 6 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/E75C8D479AC9F7CB8625682A0066141B.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/59-17-02

## The airworthiness directive

59-17-02 BOEING: Applies to all Model 707 Series Aircraft.

Compliance required as indicated.

Several reports have been received concerning the complete or partial disintegration of certain type Purolator, P/N 57737-2 filter elements used in pressure filter assembly BAC P/N F- 18C-12 (Purolator P/N 57726) and in auxiliary return filter, BAC P/N 10-3333-1 (Purolator P/N 64088).

There are two types of filter elements in use having the same P/N 57737-2. They are easily distinguishable by their design. One has a concave bottom plate and the other one a flat bottom together with nonmetallic mesh on the inner surface of the paper convolutions. Investigation has shown that the filter elements which disintegrated were of Purolator concave bottom type supplied prior to July 25, 1959.

Although all P/N 57737-2 concave bottom type filter elements may not be unsatisfactory, the number and location of unsatisfactory elements is unknown. Accordingly, to eliminate the existent adverse situation, the following must be accomplished.

  (a) All present inventories of the concave bottom type Purolator filter elements P/N 57737-2 supplied prior to July 25, 1959, must be rejected for any further use in any type certificated aircraft.

  (b) Replacement filter elements in the above noted pressure filter assembly or auxiliary return filter assembly shall utilize either the flat bottom type filter element, P/N 57737-2, or the concave bottom type P/N 57737-2 obtained from Purolator, and dated after July 25, 1959, or other approved replacement filter elements such as Aircraft Porous Media, Inc., P/N ACS-1790E- 12 or Bendix Filter Division, P/N 574615.

(Boeing service message dated July 23, 1959, also covers this subject.)

## Affected data sheets (2) (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

## 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/59-17-02/models.md
Every aircraft: https://openairdocs.org/ad/59-17-02/aircraft.md

Its text cites no advisory circulars or STCs.

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