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55-14-02: Hydraulic Cylinder Replacement

FAA order 55-14-02 is an airworthiness directive published December 4, 1956. The FAA's subject line: Hydraulic Cylinder Replacement. It names Piper PA-23 Apache and Aztec: about 1,315 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: engine.

What it applies to as the FAA lists it

Kind of product
Aircraft
Makes
Piper Aircraft Inc.
Models
PA-23
On this site
Piper PA-23 Apache and Aztec 1,315 registered

Dates and paperwork

Published
December 4, 1956
Docket
Unknown
Status
Current
The FAA's document
Read the order on the FAA's site

The order itself the regulatory text, as published

Show the full text (860 characters)
55-14-02 PIPER: Applies to Model PA-23 Serial Numbers 23-1 to 23-208 Inclusive. Compliance required by August 1, 1955. Because of possible damage to the hydraulic actuating cylinders for the landing gear system and flap system of the two end plug retaining pins, as a result of excessive pressures caused by thermal expansion, it is necessary that these cylinders be inspected and replaced or modified as follows: 1. If the cylinder housing is upset or fractured, it must be replaced by a new reinforced cylinder P/N 455927. (Piper Service Bulletin No. 138 dated May 9, 1955, covers this same subject.) 2. If the cylinder housing is not upset or fractured, it must either be replaced by P/N 455927, or reinforced by adding two retaining plugs in accordance with Piper Service Letter No. 250 dated June 8, 1955. This supersedes AD 55-12-01.

Related safety bulletins advice on the same designs, not orders

2018-11-21SW-18-31 · NAVIGATION, ATTITUDE, AND DIRECTION DATA SYSTEM
2017-02-21CE-17-08 · Main Landing Gear Drag Link Bolt
2012-09-17CE-12-44 · Exhaust systems
2008-01-09CE-08-11 · Landing Gear
2005-07-07CE-05-67 ·

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 30, 2026. Connections as data: /graph/directive/55-14-02.json · aircraft systems.