# AD 71-17-01: Fuel Line Blockage

- Type: Airworthiness directive
- Status: Current
- Products: Maule Aerospace Technology M-4-180C and M-4-220C
- Effective: August 16, 1971
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-1261
- Registered aircraft: 87 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5C77D17DE43293D286256A380064F978.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/71-17-01

## The airworthiness directive

71-17-01 MAULE AIRCRAFT: Amendment 39-1261. Applies to Model M-4-180 serial numbers 3001 C through 3005C and Model M-4-220 serial numbers 2001C through 2070C, certificated in all categories.

Compliance required within the next 50 hours' time in service after the effective date of this airworthiness directive.

To prevent fuel line blockage due to low spots and to maintain the firewall fire protection, accomplish the following:

  (1) Inspect the fuel line located underneath the front seats for low undrainable spots. If low spots are found, remove low spots by hand bending and resecure fuel line with additional clamps or ty-raps. With the aircraft in a three point position, this fuel line must have a downward slope from the right side to the left side of the aircraft.

  (2) Inspect fuel feed line firewall bulkhead fitting located on the left side of the firewall and ascertain that it is a steel AN832-6 fitting. If the fitting is aluminum, replace it with an AN832-6steel fitting.

Maule Service Letter 23 covers the above inspections and changes.

This amendment becomes effective August 16, 1971.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 3A23](https://openairdocs.org/tcds/3A23): Maule Aerospace Technology Inc.; names 2 of 50 models: M-4-180C, M-4-220C

## 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: 87 (87 by airframe model, 0 by engine model)
- Makers: Maule 87

Models with the most aircraft:

- [Maule M-4-220C](https://openairdocs.org/model/maule-m-4-220c): 83 aircraft (airframe model)
- [Maule M-4-180C](https://openairdocs.org/model/maule-m-4-180c): 4 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/71-17-01/models.md
Every aircraft: https://openairdocs.org/ad/71-17-01/aircraft.md

Its text cites no advisory circulars or STCs.

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