# AD 91-26-08: Generator Control Units (GCU) and AC Electrical Power

- Type: Airworthiness directive
- Status: Current
- Products: Airbus A300 B4-601, A300 B4-603, A300 B4-605R, A300 B4-620, A300 B4-622R, A300 F4-605R, A300 F4-622R, A310-203, A310-221, A310-222, A310-304, A310-322 and 2 more
- Effective: February 14, 1992
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-8121
- Docket: 91-NM-87-AD
- Registered aircraft: 122 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/7B24F4D14F0F3EFB8625695E006F2705.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/91-26-08

## The airworthiness directive

91-26-08 AIRBUS INDUSTRIE: Amendment 39-8121. Docket No. 91-NM-87-AD.

Applicability: Model A310 and A300-600 series airplanes, on which Modification 7769 has not been accomplished, certificated in any category.

Compliance: Required within 180 days after the effective date of this AD, unless accomplished previously.

To prevent loss of the Generator Control Units (GCU) and AC electrical power, accomplish the following:

  (a) Remove the three currently installed GCU's and replace them with three modified GCU's having protective covers, in accordance with Airbus Industrie Service Bulletins A310-24-2040, Revision 1, dated January 28, 1991 (for Model A310); A300-24-6029, Revision 1, dated February 22, 1991 (for Model A300-600); and Sundstrand Service Bulletin 735226/740206/740120-24-9 (for Models A310 and A300-600), dated June 15, 1989 (Modification 7769); as applicable.

  (b) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. The request shall be forwarded through an FAA Principal Avionics Inspector, who may concur or comment and then send it to the Manager, Standardization Branch, ANM-113.

  (c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

  (d) The installation required by this AD shall be done in accordance with Airbus Industrie Service Bulletin A310-24-2040, Revision 1, dated January 28, 1991 (for Model A310); Airbus Industrie Service Bulletin A300-24-6029, Revision 1, dated February 22, 1991 (for Model A300-600); and Sundstrand Service Bulletin 735226/740206/740120-24-9 (for Models A310 and A300-600), dated June 15, 1989 (Modification 7769). This incorporation by reference was approved by the Director of the Federal Registerin accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Airbus Industrie, Airbus Support Division, Avenue Didier Daurat, 31700 Blagnac, France. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.

  (e) This amendment (39-8121, AD 91-26-08) becomes effective on February 14, 1992.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A35EU](https://openairdocs.org/tcds/A35EU): Airbus SAS; names 14 of 17 models: A310-203, A300 B4-622R, A300 F4-605R, A300 B4-601, A310-221, A300 B4-603, A310-324, A300 F4-622R…

## 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: 122 (122 by airframe model, 0 by engine model)
- Makers: Airbus Industrie 74, Airbus 48

Models with the most aircraft:

- [Airbus Industrie A300 F4-605R](https://openairdocs.org/model/airbus-industrie-a300-f4-605r): 36 aircraft (airframe model)
- [Airbus A300 F4-622R](https://openairdocs.org/model/airbus-a300-f4-622r): 31 aircraft (airframe model)
- [Airbus Industrie A300 F4-622R](https://openairdocs.org/model/airbus-industrie-a300-f4-622r): 21 aircraft (airframe model)
- [Airbus A300 B4-622R](https://openairdocs.org/model/airbus-a300-b4-622r): 11 aircraft (airframe model)
- [Airbus Industrie A300 B4-622R](https://openairdocs.org/model/airbus-industrie-a300-b4-622r): 10 aircraft (airframe model)
- [Airbus A300 F4-605R](https://openairdocs.org/model/airbus-a300-f4-605r): 6 aircraft (airframe model)
- [Airbus Industrie A300 B4-605R](https://openairdocs.org/model/airbus-industrie-a300-b4-605r): 3 aircraft (airframe model)
- [Airbus Industrie A310-203](https://openairdocs.org/model/airbus-industrie-a310-203): 2 aircraft (airframe model)
- [Airbus Industrie A310-222](https://openairdocs.org/model/airbus-industrie-a310-222): 2 aircraft (airframe model)

All 9 models: https://openairdocs.org/ad/91-26-08/models.md
Every aircraft: https://openairdocs.org/ad/91-26-08/aircraft.md

Its text cites no advisory circulars or STCs.

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