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71-24-04: Flexible Hoses In Engine Compartment

FAA order 71-24-04 is an airworthiness directive in force since November 23, 1971. The FAA's subject line: Flexible Hoses In Engine Compartment. It names Cessna 177 Cardinal, Cessna 206 Stationair, Cessna 210 Centurion, Cessna 336, Cessna 337 Skymaster, Cessna P206 Super Skylane, Cessna T210 Turbo Centurion, Cessna T337, Cessna TP206, Cessna TU206, Cessna U206 Stationair: about 7,108 aircraft on the U.S. register today across them, 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
Cessna Aircraft Company
Models
177, 206, 210D, 210E, 210F, 210G, 210H, 336, 337, 337A, 337B, 337C, P206, P206A, P206B, P206C, T210F, T210G, T210H, T337B, T337C, TP206A, TP206B, TP206C, TU206A, TU206B, TU206C, U206, U206A, U206B, U206C
On this site
Cessna 177 Cardinal 2,158 registered
Cessna 206 Stationair 213 registered
Cessna 210 Centurion 1,527 registered
Cessna 336 35 registered
Cessna 337 Skymaster 370 registered
Cessna P206 Super Skylane 163 registered
Cessna T210 Turbo Centurion 1,282 registered
Cessna T337 193 registered
Cessna TP206 25 registered
Cessna TU206 344 registered
Cessna U206 Stationair 798 registered

Dates and paperwork

In force since
November 23, 1971
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 (2,937 characters)
71-24-04 CESSNA: Amdt. 39-1340. Applies to following airplanes: MODELS SERIAL NUMBERS AFFECTED 177 661, 17700001 and 17700003 thru 17701164 206 206-0001 thru 206-0275 U206 U206-0276 thru U206-0437 P206 P206-0002 thru P206-0160 U206A U206-0438 thru U206-0656 P206A P206-0161 thru P206-0306 TU206A U206-0487 thru U206-0656 P206B P206-0307 thru P206-0419 TU206B U206-0657 thru U206-0914 TP206A P206-191 thru P206-0306 TP206B P206-0307 thru P206-0419 U206B U206-0657 thru U206-0914 P206C, TP206C P206-0420 thru P206-0519 U206C, TU206C U206-0915 thru U206-1234 210D 21058221 thru 21058510 210E 21058511 thru 21058715 T210F T210-0001 thru T210-0197 210F 21058716 thru 21058818 T210G T210-0198 thru T210-0307 210G 21058819 thru 21058936 T210H T210-0307 thru T210-0392 210H 21058937 thru 21059062 336 633, 636, 336-001 thru 336-0195 337 337-0002 thru 337-0239 337A 337-0240 thru 337-0525 (except 337-0306 and 337-0470) 337B 337-0001, 337-0470, 337-0526 thru 337-0755 T337B 337-0001, 337-0526 thru 337-0755 (except 337-0569) 337C, T337C 337-0756 thru 337-0978 Compliance: Required as indicated, unless already accomplished. To detect leakage of flammable fluids from flexible hose assemblies in the engine compartment within 100 hours' time in service after the effective date of this AD and thereafter at intervals not to exceed 100 hours' time in service, accomplish the following: A. Visually, or by any other method approved by FAA, inspect fuel lines as follows: 1. Pressurize the fuel lines with boost pump operating in high position. When accomplishing this test, the mixture control should be in the idle cutoff position. 2. With fuel lines pressurized, examine all flexible hose exteriors in the engine compartment for evidence of fuel stains, wetness, or leakage. 3. After pressure testing fuel hoses, allow sufficient time for excess fuel to drain overboard from the engine manifold before attempting an engine start. B. Visually, or by any other method approved by the FAA, inspect oil lines for evidence of wetness or leakage. C. If, as a result of the inspections required by Paragraphs A or B, fuel and/or oil stain, wetness or leaking is found, replace with a serviceable hose assembly. D. Inspections required by Paragraphs A and B will no longer be required when hose assemblies are replaced with assemblies having a Cessna dated metal tag attached. TSO-C53a Type C approved hose assemblies are also acceptable for this replacement. (See Note 1) NOTE 1: This does not preclude continued inspections of this area as required by FAR 91. NOTE: Cessna Service Letter SE71-7, Supplement No. 1 dated November 3, 1971, covers this subject. The above airplanes use Aeroquip 601 series or Stratoflex 156 series hose assemblies available under Cessna P/N S1236-x-xxxx. The hose assemblies are identified by a steel braided exterior. This amendment becomes effective November 23, 1971.

Related safety bulletins advice on the same designs, not orders

2025-07-282025-07 · Reciprocating Engine Supercharger
2021-08-26AIR-21-16 · FLIGHT COMPARTMENT EQUIPMENT, Cessna Seat Back Attachment Bolt Inspection
2020-05-29AIR-20-10 · AD 2020-03-16 Alternative Methods of Compliance and FAQ
2018-11-21SW-18-31 · NAVIGATION, ATTITUDE, AND DIRECTION DATA SYSTEM
2017-06-09CE-17-16 · Main Landing Gear Actuator Inspection

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 26, 2026. Connections as data: /graph/directive/71-24-04.json · aircraft systems.