AD 90-26-08

final rule

Airworthiness Directives; BOEING Model 747-400 Series Airplanes

AD Number
90-26-08
Status
final_rule
Effective Date
Product Category
aircraft
Docket
90-NM-252-AD
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company 747-400 Series Airworthiness Directives; BOEING Model 747-400 Series Airplanes

Unsafe Condition

Failure of the fire detection warning system to annunciate a fire.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Modify the wiring of the aural and master warning indication systems of the fire detection system in accordance with Boeing Alert Service Bulletin 747-26A2171, dated October 4, 1990. An alternate means of compliance or adjustment of the compliance time may be used when approved by the FAA.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within 45 days after the effective date of this airworthiness directive, unless previously accomplished.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Boeing Model 747-400 series airplanes listed in Boeing Alert Service Bulletin 747-26A2171, dated October 4, 1990, certificated in any category.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

Fire Detection System

Applicability Source Text

Show captured applicability text from the source AD
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AD Number:
90-26-08
Document Type:
AD Final Rules
Docket Number:
90-NM-252-AD
Subject Heading:
Airworthiness Directives; BOEING Model 747-400 Series Airplanes
Subject:
Fire Detection System
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/26/1990
Make:
The Boeing Company
Model:
747-400 Series
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
Updated RGL applicability to match AD applicability; CAR C-11-185
AIRWORTHINESS DIRECTIVES FINAL RULES: 90-26-08
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-252-AD

AMENDMENT:   39-6831

AD NUMBER:   90-26-08

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 747-400 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 26, 1990.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
90-26-08 BOEING: Amendment 39-6831. Docket No. 90-NM-252-AD.

Applicability: Model 747-400 series airplanes, listed in Boeing Alert Service Bulletin 747-26A2171, dated October 4, 1990, certificated in any category.

Compliance: Required within 45 days after the effective date of this airworthiness directive, unless previously accomplished.

To prevent the failure of the fire detection warning system to annunciate a fire, accomplish the following:

A. Modify the wiring of the aural and master warning indication systems of the fire detection system, in accordance with Boeing Alert Service Bulletin 747-26A2171, dated October 4, 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 (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be submitted directly to the Manager, Seattle ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Seattle 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 information from the manufacturer may obtain copies upon request to Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. This information may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington.

This amendment (39-6831, AD 90-26-08) becomes effective on December 26, 1990.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_90-26-08.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
90-26-08
Document Type:
AD Final Rules
Docket Number:
90-NM-252-AD
Subject Heading:
Airworthiness Directives; BOEING Model 747-400 Series Airplanes
Subject:
Fire Detection System
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/26/1990
Make:
The Boeing Company
Model:
747-400 Series
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
Updated RGL applicability to match AD applicability; CAR C-11-185
AIRWORTHINESS DIRECTIVES FINAL RULES: 90-26-08
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   90-NM-252-AD

AMENDMENT:   39-6831

AD NUMBER:   90-26-08

SUBJECT HEADING:   Airworthiness Directives; BOEING Model 747-400 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 26, 1990.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
90-26-08 BOEING: Amendment 39-6831. Docket No. 90-NM-252-AD.

Applicability: Model 747-400 series airplanes, listed in Boeing Alert Service Bulletin 747-26A2171, dated October 4, 1990, certificated in any category.

Compliance: Required within 45 days after the effective date of this airworthiness directive, unless previously accomplished.

To prevent the failure of the fire detection warning system to annunciate a fire, accomplish the following:

A. Modify the wiring of the aural and master warning indication systems of the fire detection system, in accordance with Boeing Alert Service Bulletin 747-26A2171, dated October 4, 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 (ACO), FAA, Transport Airplane Directorate.

NOTE: The request should be submitted directly to the Manager, Seattle ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Seattle 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 information from the manufacturer may obtain copies upon request to Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124. This information may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington.

This amendment (39-6831, AD 90-26-08) becomes effective on December 26, 1990.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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