AD 81-13-07

final rule

Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes

AD Number
81-13-07
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Learjet Inc. 23 Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 24 Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 24A Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 24B Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 24B-A Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 24C Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 24D Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 24D-A Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 24E Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 24F Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 24F-A Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 25 Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 25A Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 25B Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 25C Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 25D Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 25F Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 28 Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 29 Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 35 Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 35A (C-21A) Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 36 Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
aircraft Learjet Inc. 36A Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes

Unsafe Condition

Fuel starvation and engine flameout may occur due to fuel being trapped in the aft area of the wing tank outboard of the wheel well when prolonged nose up attitude of 10 degrees or more is maintained with 600 pounds or less fuel remaining in either wing tank.

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

Required Actions

Insert FAA-approved temporary changes to the Airplane Flight Manual (Figures I, II, III) or equivalent approved by the Chief, Aircraft Certification Program Office. Operate the airplane according to the revised AFM instructions.

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

Compliance Time

within the next 50 hours time-in-service after the effective date of this AD

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

Affected Aircraft

Gates Model 23 (SN 003-099), Model 24 Series (SN 003-357), Model 25 Series (SN 003-341 except 337), Model 28 (SN 001-005), Model 29 (SN 001-003), Model 35 Series (SN 001-415), and Model 36 Series (SN 001-047)

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

Federal Register Abstract

Change to AFM Fuel Starvation

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_81-13-07.html
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Details
AD Number:
81-13-07
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
Subject:
Change to AFM Fuel Starvation
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
06/25/1981
Make:
Learjet Inc.
Model:
23 | 24 | 24A | 24B | 24B-A | 24C | 24D | 24D-A | 24E | 24F | 24F-A | 25 | 25A | 25B | 25C | 25D | 2...Show more
Product Type:
Aircraft
Product Subtype:
Small Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 81-13-07
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4139

AD NUMBER:   81-13-07

SUBJECT HEADING:   Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective June 25, 1981.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
81-13-07 GATES LEARJET: Amendment 39-4139. Applies to Models 23 (Serial Numbers 003 through 099), Model 24 Series (Serial Numbers 003 through 357), Model 25 Series (Serial Numbers 003 through 341 except 337), Model 28 (Serial Numbers 001 through 005), Model 29 (Serial Numbers 001 through 003), Model 35 Series (Serial Numbers 001 through 415) and Model 36 Series (Serial Numbers 001 through 047) airplanes.

COMPLIANCE: Required as indicated unless already accomplished.

To ensure operation without fuel starvation, within the next 50 hours time-in-service after the effective date of this AD, accomplish the following:

A) Insert in the Airplane Flight Manual the FAA Approved temporary changes shown hereinafter as Figures I, II, and III or the FAA Approved Flight Manual changes (temporary or permanent) supplied by the manufacturer and containing the same information as the above figures.

B) Operate the airplane in accordance with instructions in the Airplane Flight Manual changes specified in Paragraph A of this AD.

C) Any equivalent method of compliance with this AD must be approved by the Chief, Aircraft Certification Program Office, Room 238, Terminal Building 2299, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 942-4285.

This Amendment becomes effective on June 25, 1981.



FIGURE I


TEMPORARY FLIGHT MANUAL CHANGE

Description of Change:	Add Limitation to Section I of the Airplane Flight Manual.
Filing Instructions:	Insert this page adjacent to the "Takeoff and Landing operational Limits" in section 1 -Limitations in your Airplane Flight Manual:

Amend Section I - TAKEOFF AND LANDING OPERATIONAL LIMITS by adding the following Limitation:

FUEL LOAD - MINIMUM 600 POUNDS IN EACH WING REQUIRED FOR TAKEOFF AND INTENTIONAL GO-AROUND.

FIGURE II


TEMPORARY FLIGHT MANUAL CHANGE

Description of Change:	ADD Minimum Fuel Quantity Warning to Section II of the Airplane Flight Manual
Filing Instructions:	Insert this page adjacent to the "After Takeoff checklist of Section II - NORMAL PROCEDURES in your Airplane light Manual.
Add the following warning:

AFTER TAKEOFF:

WARNING: When the fuel quantity gage indicates 600 pounds of less remaining in either wing tank, prolonged nose up attitude of 10 degrees or more may cause fuel to be trapped in the aft area of the wing tank outboard of the wheel well. Fuel starvation and engine flameout may occur. Reducing pitch attitude and thrust to minimum required will prevent this situation.

FIGURE III


TEMPORARY FLIGHT MANUAL CHANGE

Description of Change:	ADD Minimum Fuel Quantity Warning to Section II of the Airplane Flight Manual
Filing Instructions:	Insert this page adjacent to the "Go-Around/Balked Landing" checklist of Section II-NORMAL PROCEDURES in your Airplane Flight Manual. ADD the following warning:

GO-AROUND/BALKED LANDING (ONE OR TWO ENGINE):

WARNING: When the fuel quantity gage indicates 600 pounds or less remaining in either wing tank, prolonged nose up attitude of 10 degrees or more may cause fuel to be trapped in the aft area of the wing tank outboard of the wheel well. Fuel starvation and engine flameout may occur. For go-around conditions with low fuel, on first steady indication by the LOW Fuel warning light, reduce climb attitude and thrust to minimum required.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_81-13-07.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
81-13-07
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes
Subject:
Change to AFM Fuel Starvation
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
06/25/1981
Make:
Learjet Inc.
Model:
23 | 24 | 24A | 24B | 24B-A | 24C | 24D | 24D-A | 24E | 24F | 24F-A | 25 | 25A | 25B | 25C | 25D | 2...Show more
Product Type:
Aircraft
Product Subtype:
Small Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 81-13-07
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4139

AD NUMBER:   81-13-07

SUBJECT HEADING:   Airworthiness Directives; Gates Model 23, 24, 25, 28 and 29 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective June 25, 1981.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
81-13-07 GATES LEARJET: Amendment 39-4139. Applies to Models 23 (Serial Numbers 003 through 099), Model 24 Series (Serial Numbers 003 through 357), Model 25 Series (Serial Numbers 003 through 341 except 337), Model 28 (Serial Numbers 001 through 005), Model 29 (Serial Numbers 001 through 003), Model 35 Series (Serial Numbers 001 through 415) and Model 36 Series (Serial Numbers 001 through 047) airplanes.

COMPLIANCE: Required as indicated unless already accomplished.

To ensure operation without fuel starvation, within the next 50 hours time-in-service after the effective date of this AD, accomplish the following:

A) Insert in the Airplane Flight Manual the FAA Approved temporary changes shown hereinafter as Figures I, II, and III or the FAA Approved Flight Manual changes (temporary or permanent) supplied by the manufacturer and containing the same information as the above figures.

B) Operate the airplane in accordance with instructions in the Airplane Flight Manual changes specified in Paragraph A of this AD.

C) Any equivalent method of compliance with this AD must be approved by the Chief, Aircraft Certification Program Office, Room 238, Terminal Building 2299, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 942-4285.

This Amendment becomes effective on June 25, 1981.



FIGURE I


TEMPORARY FLIGHT MANUAL CHANGE

Description of Change:	Add Limitation to Section I of the Airplane Flight Manual.
Filing Instructions:	Insert this page adjacent to the "Takeoff and Landing operational Limits" in section 1 -Limitations in your Airplane Flight Manual:

Amend Section I - TAKEOFF AND LANDING OPERATIONAL LIMITS by adding the following Limitation:

FUEL LOAD - MINIMUM 600 POUNDS IN EACH WING REQUIRED FOR TAKEOFF AND INTENTIONAL GO-AROUND.

FIGURE II


TEMPORARY FLIGHT MANUAL CHANGE

Description of Change:	ADD Minimum Fuel Quantity Warning to Section II of the Airplane Flight Manual
Filing Instructions:	Insert this page adjacent to the "After Takeoff checklist of Section II - NORMAL PROCEDURES in your Airplane light Manual.
Add the following warning:

AFTER TAKEOFF:

WARNING: When the fuel quantity gage indicates 600 pounds of less remaining in either wing tank, prolonged nose up attitude of 10 degrees or more may cause fuel to be trapped in the aft area of the wing tank outboard of the wheel well. Fuel starvation and engine flameout may occur. Reducing pitch attitude and thrust to minimum required will prevent this situation.

FIGURE III


TEMPORARY FLIGHT MANUAL CHANGE

Description of Change:	ADD Minimum Fuel Quantity Warning to Section II of the Airplane Flight Manual
Filing Instructions:	Insert this page adjacent to the "Go-Around/Balked Landing" checklist of Section II-NORMAL PROCEDURES in your Airplane Flight Manual. ADD the following warning:

GO-AROUND/BALKED LANDING (ONE OR TWO ENGINE):

WARNING: When the fuel quantity gage indicates 600 pounds or less remaining in either wing tank, prolonged nose up attitude of 10 degrees or more may cause fuel to be trapped in the aft area of the wing tank outboard of the wheel well. Fuel starvation and engine flameout may occur. For go-around conditions with low fuel, on first steady indication by the LOW Fuel warning light, reduce climb attitude and thrust to minimum required.

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.