AD 75-15-06

final rule

Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes

AD Number
75-15-06
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of an aircraft landing gear and wheel assembly
Problem area Landing gear

Applicability

TypeManufacturerModelDetails
aircraft Learjet Inc. 23 Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 24 Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 24A Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 24B Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 24B-A Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 24C Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 24D Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 24D-A Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 24E Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 24F Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 24F-A Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 25 Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 25A Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 25B Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 25C Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 25D Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
aircraft Learjet Inc. 25F Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes

Unsafe Condition

Flaws in the upper main landing gear struts could result in structural failure.

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

Required Actions

Inspect left and right upper main landing gear struts using eddy current or ultrasonic methods within 600 hours' time in service after July 25, 1975, or by September 30, 1976. If flaws are found, remove flaws under 0.025 inches within 50 hours' time in service, reinspect, and treat. Replace or modify struts with flaws over 0.025 inches.

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

Compliance Time

Within the next 600 hours' time in service after the effective date of this AD, but not later than September 30, 1976

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

Affected Aircraft

Gates Learjet Models 23 (Serial Numbers 23-003 thru 23-099); 24 (Serial Numbers 24-100 thru 24-297); and 25 (Serial Numbers 25-003 thru 25-182)

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

Federal Register Abstract

Landing Gear Struts

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_75-15-06.html
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AD Number:
75-15-06
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
Subject:
Landing Gear Struts
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
07/25/1975
Make:
Learjet Inc.
Model:
23 | 24 | 24A | 24B | 24B-A | 24C | 24D | 24D-A | 24E | 24F | 24F-A | 25 | 25A | 25B | 25C | 25D | 25F
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:
AIRWORTHINESS DIRECTIVES FINAL RULES: 75-15-06
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-2267

AD NUMBER:   75-15-06

SUBJECT HEADING:   Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective July 25, 1975.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
75-15-06 GATES LEARJET: Amendment 39-2267. Applies to 23 (Serial Numbers 23- 003 thru 23-099); 24 (Serial Numbers 24-100 thru 24-297); and 25 (Serial Numbers 25-003 thru 25-182) series airplanes.

Compliance: Required as indicated, unless already accomplished in accordance with Gates Learjet Service Bulletin No. SB 23/24/25-259A or later approved revisions.

To check for flaws in the upper main landing gear struts, accomplish the following:

A) Within the next 600 hours' time in service after the effective date of this AD, but not later than September 30, 1976, using eddy current or ultrasonic inspection equipment and procedures, inspect the left and right upper main landing gear struts for flaws in accordance with the instructions and sketches outlined in Gates Learjet Service Bulletin No. SB 23/24/25-259A or later approved revisions, or alternatively, remove the left and right upper landing gear struts from the airplane, disassemble, clean, and inspect the struts for flaws in accordance with the aforementioned Service Bulletin.

B) If, as a result of the inspections referred to in Paragraph A, flaws are detected, within the next 50 hours' time in service, accomplish the following:

1. Remove any flaw in an upper main landing gear strut with a depth less than .025 inches in accordance with the procedures outlined in the aforementioned Service Bulletin.

a. After flaw removal, reinspect using eddy current or ultrasonic methods to assure complete removal of the flaw and then treat and paint the affected area in accordance with the aforementioned Service Bulletin.

2. For flaws that exceed a depth of .025 inches, modify the upper main landing gear strut in accordance with instructions provided by the manufacturer or alternatively, replace with an airworthy part.

C) Any equivalent method of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.

NOTE: Aircraft inspected and in compliance with Gates Learjet Service Bulletin SB 23/24/25-259 (i.e., the original Service Bulletin on this subject) are considered to have complied with the requirements of this AD.

This amendment becomes effective July 25, 1975.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_75-15-06.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
75-15-06
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes
Subject:
Landing Gear Struts
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
07/25/1975
Make:
Learjet Inc.
Model:
23 | 24 | 24A | 24B | 24B-A | 24C | 24D | 24D-A | 24E | 24F | 24F-A | 25 | 25A | 25B | 25C | 25D | 25F
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:
AIRWORTHINESS DIRECTIVES FINAL RULES: 75-15-06
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-2267

AD NUMBER:   75-15-06

SUBJECT HEADING:   Airworthiness Directives; Gates Learjet Models 23, 24 and 25 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective July 25, 1975.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
75-15-06 GATES LEARJET: Amendment 39-2267. Applies to 23 (Serial Numbers 23- 003 thru 23-099); 24 (Serial Numbers 24-100 thru 24-297); and 25 (Serial Numbers 25-003 thru 25-182) series airplanes.

Compliance: Required as indicated, unless already accomplished in accordance with Gates Learjet Service Bulletin No. SB 23/24/25-259A or later approved revisions.

To check for flaws in the upper main landing gear struts, accomplish the following:

A) Within the next 600 hours' time in service after the effective date of this AD, but not later than September 30, 1976, using eddy current or ultrasonic inspection equipment and procedures, inspect the left and right upper main landing gear struts for flaws in accordance with the instructions and sketches outlined in Gates Learjet Service Bulletin No. SB 23/24/25-259A or later approved revisions, or alternatively, remove the left and right upper landing gear struts from the airplane, disassemble, clean, and inspect the struts for flaws in accordance with the aforementioned Service Bulletin.

B) If, as a result of the inspections referred to in Paragraph A, flaws are detected, within the next 50 hours' time in service, accomplish the following:

1. Remove any flaw in an upper main landing gear strut with a depth less than .025 inches in accordance with the procedures outlined in the aforementioned Service Bulletin.

a. After flaw removal, reinspect using eddy current or ultrasonic methods to assure complete removal of the flaw and then treat and paint the affected area in accordance with the aforementioned Service Bulletin.

2. For flaws that exceed a depth of .025 inches, modify the upper main landing gear strut in accordance with instructions provided by the manufacturer or alternatively, replace with an airworthy part.

C) Any equivalent method of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.

NOTE: Aircraft inspected and in compliance with Gates Learjet Service Bulletin SB 23/24/25-259 (i.e., the original Service Bulletin on this subject) are considered to have complied with the requirements of this AD.

This amendment becomes effective July 25, 1975.

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.