# AD 90-11-11: Oxygen/Yaw Damper Module

- Type: Airworthiness directive
- Status: Current
- Products: Boeing 747-400 Series
- Effective: June 11, 1990
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-6610
- Docket: 90-NM-70-AD
- Registered aircraft: 38 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/064F06A4EFA0E3EB86256960004861D9.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/90-11-11

## The airworthiness directive

90-11-11 BOEING: Amendment 39-6610. Docket No. 90-NM-70-AD.

Applicability: Model 747-400 series airplanes, listed in Boeing Alert Service Bulletin 747-35A2067, dated March 15, 1990, certificated in any category.

Compliance: Required within the next 500 hours time-in-service after the effective date of this AD, unless previously accomplished.

To prevent disablement of the passenger oxygen system, accomplish the following:

A. Remove and replace the passenger oxygen/yaw damper module in accordance with Boeing Alert Service Bulletin 747-35A2067, dated March 15, 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, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment, and then send it to the Manager,Seattle Aircraft Certification Office.

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 information from the manufacturer may obtain copies upon request to Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124. This information may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington.

This amendment (39-6610, AD 90-11-11) becomes effective on June 11, 1990.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A20WE](https://openairdocs.org/tcds/A20WE): The Boeing Company; names 1 of 14 models: 747-400 Series

## 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: 38 (38 by airframe model, 0 by engine model)
- Makers: Boeing 38

Models with the most aircraft:

- [Boeing 747-446](https://openairdocs.org/model/boeing-747-446): 10 aircraft (airframe model)
- [Boeing 747-422](https://openairdocs.org/model/boeing-747-422): 8 aircraft (airframe model)
- [Boeing 747-412](https://openairdocs.org/model/boeing-747-412): 5 aircraft (airframe model)
- [Boeing 747-409](https://openairdocs.org/model/boeing-747-409): 4 aircraft (airframe model)
- [Boeing 747-481](https://openairdocs.org/model/boeing-747-481): 3 aircraft (airframe model)
- [Boeing 747-443](https://openairdocs.org/model/boeing-747-443): 2 aircraft (airframe model)
- [Boeing 747-438](https://openairdocs.org/model/boeing-747-438): 2 aircraft (airframe model)
- [Boeing 747-428](https://openairdocs.org/model/boeing-747-428): 2 aircraft (airframe model)
- [Boeing 747-400](https://openairdocs.org/model/boeing-747-400): 1 aircraft (airframe model)
- [Boeing 747-451](https://openairdocs.org/model/boeing-747-451): 1 aircraft (airframe model)

All 10 models: https://openairdocs.org/ad/90-11-11/models.md
Every aircraft: https://openairdocs.org/ad/90-11-11/aircraft.md

Its text cites no advisory circulars or STCs.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.