# AD 78-18-05: Wing Tank Fuel Quantity Indicator

- Type: Airworthiness directive
- Status: Current
- Products: Aerostar PA-60-600 (Aerostar 600), PA-60-601 (Aerostar 601) and PA-60-601P (Aerostar 601P)
- Effective: September 13, 1978
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-3295
- Registered aircraft: 9 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/299B784662E90F248625699E004ADE9F.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/78-18-05

## The airworthiness directive

78-18-05 PIPER AEROSTAR: Amendment 39-3295. Applies to Piper Aerostar Model 600, 601 and 601P airplanes certificated in all categories, serial numbers 150 through 520.

Compliance required as indicated. To prevent reversed readings of left and right wing tank fuel quantity accomplish the following:

  (a) Within 10 hours time in service after the effective date of this AD, unless already accomplished, with LH and RH wing tanks at least 50% depleted from tank capacity:

1) Read and record fuel quantity indication for LH and RH wing fuel tanks.

2) Add 10 gallons of fuel to one wing tank only.

3) Read and record fuel quantity for each wing tank.

4) Determine that the added fuel registers on the correct wing tank fuel quantity indicator selector position.

5) If the correct wing tank fuel quantity selector position registers the added fuel, the system is normal and no further action is required under this AD.

  (b) If the appropriate wing tank fuel indicator position does not correctly register the added fuel the system may be improperly wired or the selector may be improperly indexed. In this event, prior to further flight:

Correct the fuel quantity indicating system malfunction. Refer to figure 1 for details of proper switch installation.

  (c) Within 10 hours time in service after the effective date of this AD, on those airplanes with the fuel quantity indicating selector switch relabelled as an interim solution under (B)(2) of the original message of July 7, 1978, correct the fuel quantity indicating system as in (b) of this AD and revert to standard switch labelling.

  (d) Special flight permits may be issued in accordance with FARs 21.197 and 21.199 to operate aircraft to a base for accomplishment of the repair required by paragraph (b) of this AD.

  (e) Equivalent inspections and repairs may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region.

This amendment becomes effective September 13, 1978.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A17WE](https://openairdocs.org/tcds/A17WE): Aerostar Aircraft Corporation; names 3 of 5 models: PA-60-601P (Aerostar 601P), PA-60-601 (Aerostar 601), PA-60-600 (Aerostar 600)

## 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: 9 (9 by airframe model, 0 by engine model)
- Makers: Piper 9

Models with the most aircraft:

- [Piper PA-60-601P](https://openairdocs.org/model/piper-pa-60-601p): 9 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/78-18-05/models.md
Every aircraft: https://openairdocs.org/ad/78-18-05/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.