# AD 58-01-01: Fuel Vent Line Replacement

- Type: Airworthiness directive
- Status: Current
- Products: Twin Commander 520, 560, 560-A, 560-E and 680
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 41 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/29CDE44AA6DD0B5C86256A38005BF97F.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/58-01-01

## The airworthiness directive

58-01-01 AERO COMMANDER: Applies to All Models 520, 560, 560A, 560E and 680 Aircraft With Serial Numbers 231 Through 580 except 315, 466, 471, 485, 492, 509, 523, 547, 568, 570, 572, 574, 576, 579.

Compliance required as soon as possible but not later than July 1, 1958.

A number of failures of the vent lines located above the nacelle upper fire shield have resulted in the release of fuel and/or fuel vapor in the engine compartment creating a dangerous fire hazard. These failures are a result of interference or chafing between wing structure and the carburetor return and the fuel tank vent lines. Also, failures have occurred at the carburetor vapor return elbow located in the upper fire shield.

Replace the portions of the carburetor vapor vent and fuel tank vent lines located above the upper fire shield with flexible hose assemblies, P/N 6630086-237, 6630086-223, and 6630086-229, or equivalent. Securely fasten the hose assemblies to the wing structure with hose clamps to prevent interference or chafing.

Replace the existing carburetor vapor return line elbows located at the upper fire shield with antirotation fittings, P/N 5630085-21 and 5630085-29, and install upper fire shield channels, P/N 5630086-25 and 5630086-23. (Additional details relative to this rework are included in Aero Design Service Bulletin No. 45 dated September 20, 1957.)

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 6A1](https://openairdocs.org/tcds/6A1): Twin Commander Aircraft LLC; names 4 of 9 models: 520, 560, 560A, 560E
- [TCDS 2A4](https://openairdocs.org/tcds/2A4): Twin Commander Aircraft LLC; names 1 of 21 models: 680

## 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: 41 (41 by airframe model, 0 by engine model)
- Makers: Aero Commander 41

Models with the most aircraft:

- [Aero Commander 520](https://openairdocs.org/model/aero-commander-520): 12 aircraft (airframe model)
- [Aero Commander 680](https://openairdocs.org/model/aero-commander-680): 12 aircraft (airframe model)
- [Aero Commander 560-A](https://openairdocs.org/model/aero-commander-560-a): 10 aircraft (airframe model)
- [Aero Commander 560-E](https://openairdocs.org/model/aero-commander-560-e): 5 aircraft (airframe model)
- [Aero Commander 560](https://openairdocs.org/model/aero-commander-560): 2 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/58-01-01/models.md
Every aircraft: https://openairdocs.org/ad/58-01-01/aircraft.md

Its text cites no advisory circulars or STCs.

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