# AD 57-10-02: Oil Pressure Gage Line

- Type: Airworthiness directive
- Status: Current
- Products: Piper PA-23
- Published: August 1, 1957
- Issued: August 1, 1957
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 155 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/ECD69A02B3D9E12C8625698B00764D17.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/57-10-02

## The airworthiness directive

57-10-02 PIPER: Applies to Model PA-23 Aircraft Serial Numbers 23-1 to 23-1391 Inclusive.

Compliance required as soon as possible but not later than June 15, 1957.

It has been reported that the flare on the oil pressure gage line has cracked or broken where it attaches to the connector fitting on the aft side of the firewall resulting in loss of oil pressure.

Inspect both right and left oil pressure line flares to determine whether or not they are normal and also to determine that the lines in the area of the flares are not cracked or broken.

Lines that are cracked or broken or have defective flares should be cut off and reflared. Care should be taken that there is no line strain against the fitting or the retainer block and that the line into the fitting is straight. If the line is too short for this repair, it should be cut off and spliced using a connector and flexible hose, Piper P/N 17766-07 or equivalent.

(Piper Service Bulletin No. 152A covers this subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 1A10](https://openairdocs.org/tcds/1A10): Piper Aircraft Inc.; names 1 of 6 models: PA-23

## 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: 155 (155 by airframe model, 0 by engine model)
- Makers: Piper 155

Models with the most aircraft:

- [Piper PA-23](https://openairdocs.org/model/piper-pa-23): 155 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/57-10-02/models.md
Every aircraft: https://openairdocs.org/ad/57-10-02/aircraft.md

Its text cites no advisory circulars or STCs.

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