# AD 79-20-07: Lighter Circuit Breaker

- Type: Airworthiness directive
- Status: Current
- Products: Piper PA-31, PA-31-325 and PA-31-350
- Effective: October 2, 1979
- Published: September 22, 1979
- Issued: September 22, 1979
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-3573
- Registered aircraft: 562 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/20375D8E865A55BC8625699E004AF750.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/79-20-07

## The airworthiness directive

79-20-07 PIPER AIRCRAFT CORPORATION: Amendment 39-3573. Applies to the following Piper Models of airplanes, equipped with three 12 volt cigar lighters powered through a triplet of voltage dropping resistors, certificated in all categories; PA-31 and PA-31-325, S/N 31- 7712074 through 31-7912098 and PA-31-350, S/N 31-7752096 through 31-7952197.

Compliance is required within the next 25 hours time in service or 30 days, whichever occurs first, after the effective date of this AD unless already accomplished.

To prevent smoke in the cockpit, accomplish the following:

a. For Models PA-31 and PA-31-325, S/N 31-7712074 to, but not including, 31- 7912001, and PA-31-350, S/N 31-7752096 to, but not including, 31-7952001; disconnect wire CIG-1 from the 7 amp circuit breaker located at the voltage dropping resistor assembly under the instrument panel or disconnect wire CIG-1A from the 15 amp "Heater and Cigar Lighter" circuit breaker located on the pilot's circuit breaker panel.

b. For Models PA-31 and PA-31-325, S/N 31-7912001 through 31-7912098, and PA-31-350, S/N 31-7952001 through 31-7952197, except 31-7952191, 31-7952193, 31- 7952195; disconnect wire CIG-1 from the 7 amp "Lighter" circuit breaker located on the pilot's circuit breaker panel.

c. After disconnection, protect the wire by insulating its disconnected end and fold the wire end back against itself or the bundle in which it is routed and secure it.

Compliance with the provisions of this Airworthiness Directive may be accomplished in an equivalent manner approved by the Chief, Engineering and Manufacturing Branch, FAA, Southern region.

This amendment is effective October 2, 1979.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A20SO](https://openairdocs.org/tcds/A20SO): Piper Aircraft Inc.; names 3 of 4 models: PA-31, PA-31-325, PA-31-350

## 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: 562 (562 by airframe model, 0 by engine model)
- Makers: Piper 562

Models with the most aircraft:

- [Piper PA-31-350](https://openairdocs.org/model/piper-pa-31-350): 399 aircraft (airframe model)
- [Piper PA-31-325](https://openairdocs.org/model/piper-pa-31-325): 137 aircraft (airframe model)
- [Piper PA-31](https://openairdocs.org/model/piper-pa-31): 26 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/79-20-07/models.md
Every aircraft: https://openairdocs.org/ad/79-20-07/aircraft.md

Its text cites no advisory circulars or STCs.

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