# AD 59-16-01: Fuel Line Routing

- Type: Airworthiness directive
- Status: Current
- Products: Twin Commander 500, 520, 560, 560-A, 560-E, 680, 680-E and 720
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 58 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C16790405F346FD186256A38005C0BDF.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/59-16-01

## The airworthiness directive

59-16-01 AERO COMMANDER: Applies to All Models 500, 520, 560, 560A, 560E, 680, 680E, 720 Aircraft, Serial Numbers 231 Through 690.

Compliance required not later than September 15, 1959.

To improve fuel line routing and to eliminate the possibility of a sump being formed between the fuel shut-off valve and the booster pump, the following inspection and/or rework is necessary.

  (a) If inspection reveals excessive line lengths are creating water traps or low spots in the fuel line between the fuel shut-off valve and the fuel booster pumps, clamp the lines up to existing structure until a uniform slope is obtained.

  (b) If a uniform slope cannot be obtained by clamping up the line, remove the existing 45 degrees elbow at the shut-off valve and replace it with an AN 822-8D 90 degrees elbow.

  (c) If a uniform slope cannot be obtained after completing items (a) and (b), shorten fuel line until no low spots will exist upon reassembling and installation.

  (d) If existing hoses cannot be shortened, new hoses may be obtained from the manufacturer or Aero Commander distributor.

See Aero Design Service Bulletin Number 54 for hose assembly part numbers and hose lengths.

## 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 5 of 9 models: 500, 520, 560, 560A, 560E
- [TCDS 2A4](https://openairdocs.org/tcds/2A4): Twin Commander Aircraft LLC; names 3 of 21 models: 680-E, 720, 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: 58 (58 by airframe model, 0 by engine model)
- Makers: Aero Commander 58

Models with the most aircraft:

- [Aero Commander 500](https://openairdocs.org/model/aero-commander-500): 12 aircraft (airframe model)
- [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 680-E](https://openairdocs.org/model/aero-commander-680-e): 4 aircraft (airframe model)
- [Aero Commander 560](https://openairdocs.org/model/aero-commander-560): 2 aircraft (airframe model)
- [Aero Commander 720](https://openairdocs.org/model/aero-commander-720): 1 aircraft (airframe model)

All 8 models: https://openairdocs.org/ad/59-16-01/models.md
Every aircraft: https://openairdocs.org/ad/59-16-01/aircraft.md

Its text cites no advisory circulars or STCs.

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