# AD 72-21-03: Fuel Line Failure - Type: Airworthiness directive - Status: Current - Products: Piper PA-20, PA-20-115, PA-20-135, PA-20S, PA-20S-115, PA-20S-135, PA-22, PA-22-108, PA-22-135, PA-22-150, PA-22-160, PA-22S-135 and 2 more - Effective: October 13, 1972 - Published: October 7, 1972 - Issued: September 28, 1972 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Amendment: 39-1533 - Registered aircraft: 3,265 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/7908AA42BC8FB9E286256A1C006FE609.0001 - DRS record last changed: November 21, 2025 - Page: https://openairdocs.org/ad/72-21-03 ## The airworthiness directive 72-21-03 PIPER: Amdt. 39-1533. Applies to all PA-20 type aircraft S/N 20-1 and up and PA-22 type aircraft S/N 22-1 to 22-9393 inclusive. Compliance required within 100 hours in service or at next annual inspection, whichever occurs first, after the effective date of this AD unless already accomplished. To prevent potential in-flight fire due to fuel line failure, accomplish the following: Identify the flexible fuel line assembly routed from fuel strainer to the carburetor. A metal identification band permanently affixed to each line may be used for this purpose. Replace any P/N 70322-32 hose assembly with P/N 17766-66 hose assembly or an equivalent part approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. If the fuel line cannot be identified, it shall also be replaced with P/N 17766-66. Installation and routing of replacement hose assemblies shall be accomplished so as to prevent abrasion, interference chafing, and heat damage.Upon request, and submission of substantiating data through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, may adjust the compliance time specified in this AD. (Piper Service Bulletin No. 351 dated 3 May 1972 pertains to this subject.) This amendment is effective October 13, 1972. ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS 1A6](https://openairdocs.org/tcds/1A6): Piper Aircraft Inc.; names 8 of 8 models: PA-22S-135, PA-22S-150, PA-22-108, PA-22-160, PA-22-150, PA-22, PA-22S-160, PA-22-135 - [TCDS 1A4](https://openairdocs.org/tcds/1A4): Piper Aircraft Inc.; names 6 of 6 models: PA-20, PA-20S-135, PA-20-135, PA-20S-115, PA-20-115, PA-20S ## 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: 3,265 (3,265 by airframe model, 0 by engine model) - Makers: Piper 3,264, Piper/Pierce Tony 1 Models with the most aircraft: - [Piper PA-22-150](https://openairdocs.org/model/piper-pa-22-150): 1,200 aircraft (airframe model) - [Piper PA-22-108](https://openairdocs.org/model/piper-pa-22-108): 587 aircraft (airframe model) - [Piper PA-22-160](https://openairdocs.org/model/piper-pa-22-160): 456 aircraft (airframe model) - [Piper PA-22-135](https://openairdocs.org/model/piper-pa-22-135): 409 aircraft (airframe model) - [Piper PA-22](https://openairdocs.org/model/piper-pa-22): 277 aircraft (airframe model) - [Piper PA-20](https://openairdocs.org/model/piper-pa-20): 276 aircraft (airframe model) - [Piper PA-20-135](https://openairdocs.org/model/piper-pa-20-135): 42 aircraft (airframe model) - [Piper PA-22S-150](https://openairdocs.org/model/piper-pa-22s-150): 8 aircraft (airframe model) - [Piper PA-22S-135](https://openairdocs.org/model/piper-pa-22s-135): 4 aircraft (airframe model) - [Piper PA-20S-135](https://openairdocs.org/model/piper-pa-20s-135): 2 aircraft (airframe model) - [Piper PA-20S](https://openairdocs.org/model/piper-pa-20s): 1 aircraft (airframe model) - [Piper PA-20-115](https://openairdocs.org/model/piper-pa-20-115): 1 aircraft (airframe model) - [Piper/Pierce Tony PA-22-150](https://openairdocs.org/model/piper-pierce-tony-pa-22-150): 1 aircraft (airframe model) - [Piper PA-22S-160](https://openairdocs.org/model/piper-pa-22s-160): 1 aircraft (airframe model) All 14 models: https://openairdocs.org/ad/72-21-03/models.md Every aircraft: https://openairdocs.org/ad/72-21-03/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.