53-24-04: Fuel-Hydraulic Lines
FAA order 53-24-04 is an airworthiness directive published December 4, 1956. The FAA's subject line: Fuel-Hydraulic Lines. It names Piper PA-18 Super Cub, Piper PA-20 Pacer, Piper PA-22 Tri-Pacer and Colt: about 6,886 aircraft on the U.S. register today across them, though an order usually covers particular versions or serial numbers rather than every one. System: heating, ice protection and utility systems.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Piper Aircraft Inc.
- Models
- PA-18, PA-20, PA-22
- On this site
- Piper PA-18 Super Cub 3,620 registered
Piper PA-20 Pacer 323 registered
Piper PA-22 Tri-Pacer and Colt 2,943 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 (774 characters)
53-24-04 PIPER: Applies to PA-18, Serial Numbers 18-1 to 18-3000 Inclusive; PA-20, Serial Numbers 20-1 to 20-928 Inclusive; and PA-22, Serial Numbers 22-1 to 22-1689 Inclusive.
Compliance required not later than February 1, 1954.
In order to preclude the possibility of loss of fuel and hydraulic oil and fire in flight caused by chafing of these lines between the firewall and muffler, the following should be accomplished:
(a) To prevent contact with the muffler, reroute the fuel primer line, and wheel brake hydraulic line if necessary, so that they do not pass behind the muffler.
(b) Use clamps to fasten the lines to the firewall to prevent movement and vibration of these lines.
(Piper Aircraft Corp. Service Letter No. 213 covers this alteration.)
Related safety bulletins advice on the same designs, not orders
2018-11-21SW-18-31 · NAVIGATION, ATTITUDE, AND DIRECTION DATA SYSTEM
2013-05-09CE-13-30 · IGNITION SYSTEM Toggle Style Magneto Switches on the Left Side Cabin Adjacent to the Pilot Seat
2013-02-06CE-13-14 · Fuselage Cracking at Aft Tail Post Weld Joint on Piper Model PA-18 (L-21) Airplanes
2005-07-07CE-05-67 ·
2005-03-24CE-03-02R1 ·
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 November 6, 2026. Connections as data: /graph/directive/53-24-04.json · aircraft systems.