# AD 91-07-05: Avionics Standard Comm. Bus.

- Type: Airworthiness directive
- Status: Current
- Products: Gulfstream Aerospace G-IV
- Effective: April 22, 1991
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-6942
- Docket: 90-NM-187-AD
- Registered aircraft: 369 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F1C835DAC38ADAF286256A2A005651F6.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/91-07-05

## The airworthiness directive

91-07-05 GULFSTREAM: Amendment 39-6942. Docket No. 90-NM-187-AD. Applicability: Model G-IV series airplanes, Serial Numbers 1060 through 1089, certificated in any category.

Compliance: Required as indicated, unless previously accomplished.

To prevent hazardous operation of the Avionics Standard Communication Bus (ASCB) during turbulent weather conditions (Instrument Meteorological Conditions), accomplish the following:

A. Within 180 days after the effective date of this AD, perform a detailed integrity test of the ASCB, in accordance with Gulfstream Aerospace Report No. GIV-GER-276, "ASCB Databus Cable, Coupler, and Connector Integrity Test: Phase II Incorporation," dated April 2, 1990. If defective ASCB connectors are found, prior to further flight, repair or replace all defective connectors in accordance with Gulfstream Aerospace Report No. GIV-GER-276, dated April 2, 1990.

B. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Atlanta Aircraft Certification Office (ACO), FAA, Small Airplane Directorate.

NOTE: The request should be submitted directly to the Manager, Atlanta ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Manager, Atlanta ACO.

C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Gulfstream Aerospace Corporation, P.O. Box 2206, Savannah, Georgia 31402-2206. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington, or at the FAA, Small Airplane Directorate, Atlanta Aircraft Certification Office, 1669 Phoenix Parkway, Suite 210C, Atlanta, Georgia.

This amendment (39-6942, AD 91-07-05) becomes effective on April 22, 1991.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A12EA](https://openairdocs.org/tcds/A12EA): Gulfstream Aerospace Corporation; names 1 of 7 models: G-IV

## 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: 369 (369 by airframe model, 0 by engine model)
- Makers: Gulfstream Aerospace 369

Models with the most aircraft:

- [Gulfstream Aerospace G-IV](https://openairdocs.org/model/gulfstream-aerospace-g-iv): 357 aircraft (airframe model)
- [Gulfstream Aerospace G-IV (G400)](https://openairdocs.org/model/gulfstream-aerospace-g-iv-g400): 8 aircraft (airframe model)
- [Gulfstream Aerospace G-IV (G350)](https://openairdocs.org/model/gulfstream-aerospace-g-iv-g350): 2 aircraft (airframe model)
- [Gulfstream Aerospace G-IV (G300)](https://openairdocs.org/model/gulfstream-aerospace-g-iv-g300): 2 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/91-07-05/models.md
Every aircraft: https://openairdocs.org/ad/91-07-05/aircraft.md

Its text cites no advisory circulars or STCs.

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