AD 90-26-54
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 747-400 Series | Airworthiness Directives; BOEING Model 747-400 Series Airplanes |
Unsafe Condition
Uncommanded leading edge flap retraction during takeoff roll.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to add the statement 'Dispatch with an inoperative thrust reverser is prohibited.' An alternate means of compliance or adjustment of the compliance time may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 10 days after the effective date of this AD, unless previously accomplished.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
All Model 747-400 series airplanes, certificated in any category.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
AFM Change Thrust Reverser
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_90-26-54.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 90-26-54 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BOEING Model 747-400 Series Airplanes Subject: AFM Change Thrust Reverser Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 05/29/1991 Make: The Boeing Company Model: 747-400 Series Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: Updated RGL applicability to match AD applicability; CAR C-11-185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: 90-26-54 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-6994 AD NUMBER: 90-26-54 SUBJECT HEADING: Airworthiness Directives; BOEING Model 747-400 Series Airplanes ACTION: SUMMARY: DATES: Effective May 29, 1991. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 90-26-54 BOEING: Amendment 39-6994. Docket 90-NM-284-AD. Final Rule of telegraphic AD. Applicability: All Model 747-400 series airplanes, certificated in any category. Compliance: Required within 10 days after the effective date of this AD, unless previously accomplished. To prevent uncommanded leading edge flap retraction during takeoff roll, accomplish the following: A. Revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to add the following statement. This may be accomplished by inserting a copy of this AD in the AFM. "Dispatch with an inoperative thrust reverser is prohibited." 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. This amendment (39-6994, AD 90-26-54) becomes effective on May 29, 1991, as to all persons, except those persons to whom it was made immediately effective by telegraphic AD T90-26-54, issued December 24, 1990, which contained this amendment. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_90-26-54.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 90-26-54 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BOEING Model 747-400 Series Airplanes Subject: AFM Change Thrust Reverser Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 05/29/1991 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: 90-26-54 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-6994 AD NUMBER: 90-26-54 SUBJECT HEADING: Airworthiness Directives; BOEING Model 747-400 Series Airplanes ACTION: SUMMARY: DATES: Effective May 29, 1991. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 90-26-54 BOEING: Amendment 39-6994. Docket 90-NM-284-AD. Final Rule of telegraphic AD. Applicability: All Model 747-400 series airplanes, certificated in any category. Compliance: Required within 10 days after the effective date of this AD, unless previously accomplished. To prevent uncommanded leading edge flap retraction during takeoff roll, accomplish the following: A. Revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to add the following statement. This may be accomplished by inserting a copy of this AD in the AFM. "Dispatch with an inoperative thrust reverser is prohibited." 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. This amendment (39-6994, AD 90-26-54) becomes effective on May 29, 1991, as to all persons, except those persons to whom it was made immediately effective by telegraphic AD T90-26-54, issued December 24, 1990, which contained this amendment. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.
Related Airworthiness Directives
2025-15-07 Recurring
final ruleAirworthiness Directives; The Boeing Company Airplanes
Unsafe Condition: uncommanded fore and aft movement of the Captain's and First Officer's seats, which could cause a flight control obstruction or unintended flight control input, resulting in the loss of the ability...
2025-09-08
final ruleAirworthiness Directives; The Boeing Company Airplanes
Unsafe Condition: Outboard elevators without balance weights could result in abnormal vibration, buffeting, flutter, or oscillation that could result in loss of continued safe flight and landing. Additionally, outbo...
2025-03-10
final ruleAirworthiness Directives; The Boeing Company Airplanes
Unsafe Condition: Separation of a fitting and steel water supply tube above an electronics equipment cooling air filter, behind the forward cargo compartment left sidewall, leading to water leaks into the main elect...
2025-02-05
final ruleAirworthiness Directives; The Boeing Company Airplanes
Unsafe Condition: improper inner diameter grinding of landing gear outer cylinders, resulting in possible heat damage to the outer cylinder of the nose landing gear (NLG), body landing gear (BLG), and wing landing g...
