# AD 91-10-04: Exhaust Transition Flange Bolts

- Type: Airworthiness directive
- Status: Current
- Products: Lycoming Engines TIO-540-AE2A
- Effective: May 21, 1991
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-6981
- Docket: 91-ANE-10
- Registered aircraft: 5,565 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/79D22B22F8BC3ACB8625684A0055E116.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/91-10-04

## The airworthiness directive

91-10-04 TEXTRON LYCOMING: Amendment 39-6981. Docket No. 91-ANE-10. Applicability: Textron Lycoming Model TIO-540-AE2A engines, with serial numbers up to but not including L9161-61A, except L9157-61A, installed in Piper Malibu Mirage aircraft. Compliance: Required as indicated, unless previously accomplished. To prevent engine power loss, engine fire, and possible loss of aircraft, accomplish the following: (a) Remove and replace exhaust transition flange bolts, within the next 10 hours in service, after the effective date of this AD, in accordance with the following procedures: (1) Apply penetrating oil to existing exhaust transition flange bolts and remove the two bolts. (2) Install the following hardware in place of the removed bolts:

LYCOMING PART NO. DESCRIPTION QUANTITY LW-31SS-1.19 Bolt 2 77611 Gasket 1 STD-2043 Nut 2

  (3) Torque the bolts to 17 ft.-lbs. (Do not use lockwashers on the bolts.) It may be necessary to start thelock nut prior to torqueing. (4) Install the locknuts on the protruding threads of the bolts, and insure that the bolts do not loosen during installation. (5) Recheck torque on bolt heads to ensure proper torque is retained (17 ft.-lbs.) NOTE: Further information can be obtained from Textron Lycoming Service Bulletin No. 491A, dated February 21, 1990. (b) Aircraft may be ferried in accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD can be accomplished. (c) Upon submission of substantiating data by an owner or operator through an FAA Inspector (maintenance, avionics, or operations, as appropriate), an alternate method of compliance with the requirements of this AD or adjustments to the compliance schedule specified in this AD may be approved by the Manager, New York Aircraft Certification Office, ANE-170, Engine and Propeller Directorate, Aircraft Certification Service, FAA, New England Region, 181 South Franklin Avenue, Room 202, Valley Stream, New York 11581. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Textron Lycoming/Subsidiary of Textron Inc., Williamsport, Pennsylvania 17701. These documents may be examined at the FAA, New England Region, Office of the Assistant Chief Counsel, Room 311, 12 New England Executive Park, Burlington, Massachusetts. This amendment (39-6981, AD 91-10-04) becomes effective on May 21, 1991.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E14EA](https://openairdocs.org/tcds/E14EA): Lycoming Engines; names 1 of 40 models: TIO-540-AE2A

## 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: 5,565 (0 by airframe model, 5,565 by engine model)
- Makers: Piper 4,110, Cessna 633, Mooney 222, Aero Commander 117, Bellanca 111, Smith 98, Rockwell International 92, Socata 51, Commander 21, Aerofab 17

Models with the most aircraft:

- [Lycoming TI0-540 series](https://openairdocs.org/engine/lycoming-ti0-540-series): 4,886 aircraft (engine model)
- [Lycoming TIO-540-AE2A](https://openairdocs.org/engine/lycoming-tio-540-ae2a): 488 aircraft (engine model)
- [Lycoming TIO-540 series](https://openairdocs.org/engine/lycoming-tio-540-series): 191 aircraft (engine model)

All 5 models: https://openairdocs.org/ad/91-10-04/models.md
Every aircraft: https://openairdocs.org/ad/91-10-04/aircraft.md

Its text cites no advisory circulars or STCs.

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