# AD 86-10-03: Placard - Fire Prevention

- Type: Airworthiness directive
- Status: Current
- Products: Textron MU-300 and MU-300-10
- Effective: June 2, 1986
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-5312
- Registered aircraft: 17 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/BB1581DE47FEEAC18625698A007315B8.0001
- DRS record last changed: January 21, 2026
- Page: https://openairdocs.org/ad/86-10-03

## The airworthiness directive

86-10-03 MITSUBISHI: Amendment 39-5312. Applies to Model MU-300, Serial Numbers A003SA through A091SA; and Model MU-300-10, Serial Numbers A-1001SA through A1011SA; certificated in any category. To prevent cabin and engine compartment fires, accomplish the following:

A. Within 15 days after the effective date of this AD, affix a placard immediately adjacent to the engine START switch, worded as follows: "AFTER ENGINE(S) START, CONTINUED OPERATION WITH ANY ENGINE START OR DISENGAGE ANNUNCIATION IS PROHIBITED." This placard must consist of 0.1-inch red letters on a white background and may be of a plastic adhesive type, purchased locally. The placard, which is contained with Beech Aircraft Corporation MU-300/MU-300-10 Safety Communique, dated April 1986, is an acceptable placard. The placard may be removed from MU-300 airplanes when the Airplane Flight Manual for these airplanes has been changed in accordance with paragraph B., below, and the airplane has been modified in accordance with paragraph C., below. The placard may be removed from MU-300-10 airplanes when the airplane has been modified in accordance with paragraph C., below.

B. Within 15 days after the effective date of this AD, incorporate the following into the Normal Procedure Starting Engines Section of the MU-300 (Diamond I) Airplane Flight Manual: "CHECK STARTER DISENGAGEMENT AT APPROXIMATELY 32 PERCENT N2. IF STARTER HAS NOT DISENGAGED BY 45 PERCENT N2, PLACE THRUST LEVER IN CUTOFF POSITION AND REMOVE ALL ELECTRICAL POWER." This may be accomplished by including a copy of this AD in the airplane flight manual.

C. Within the next 200 hours time-in-service after the effective date of this AD, replace the airplane starter relay in accordance with Mitsubishi Service Bulletin SB 74-001, dated April 25, 1986 (for Model MU-300 airplanes), or SB 74-002, dated April 25, 1986 (for Model MU-300-10 airplanes), or later FAA-approved revisions.

D. Special flight permits may be issued inaccordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of the modifications required by this AD.

E. An alternate means of compliance which provides an acceptable level of safety may be used when approved by the Manager, Airplane Certification Branch, FAA, Southwest Region.

This amendment becomes effective on June 2, 1986.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A14SW](https://openairdocs.org/tcds/A14SW): Textron Aviation Inc.; names 1 of 1 models: MU-300
- [TCDS A16SW](https://openairdocs.org/tcds/A16SW): Textron Aviation Inc.; names 1 of 4 models: MU-300-10

## 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: 17 (17 by airframe model, 0 by engine model)
- Makers: Mitsubishi 17

Models with the most aircraft:

- [Mitsubishi MU-300](https://openairdocs.org/model/mitsubishi-mu-300): 17 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/86-10-03/models.md
Every aircraft: https://openairdocs.org/ad/86-10-03/aircraft.md

Its text cites no advisory circulars or STCs.

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