AD 93-24-10

final rule

Airworthiness Directives; Learjet Model 55, 55B, and 55C Airplanes

AD Number
93-24-10
Status
final_rule
Effective Date
Product Category
aircraft
Docket
93-NM-95-AD
FR Citation
This information is not available.
Technical illustration of an aircraft electrical generator and wiring assembly
Problem area Electrical system

Applicability

TypeManufacturerModelDetails
aircraft Learjet Inc. 55 Airworthiness Directives; Learjet Model 55, 55B, and 55C Airplanes
aircraft Learjet Inc. 55B Airworthiness Directives; Learjet Model 55, 55B, and 55C Airplanes
aircraft Learjet Inc. 55C Airworthiness Directives; Learjet Model 55, 55B, and 55C Airplanes

Unsafe Condition

The loss of both generators during flight due to wiring issues in the left- and right-hand generator interface boxes and between these boxes.

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

Required Actions

Modify the wiring inside the left- and right-hand generator interface boxes and between these boxes, perform an operational test of the DC power distribution system in accordance with Learjet Service Bulletin SB 55-24-4, and submit requests for alternative methods of compliance through an appropriate FAA Principal Maintenance Inspector.

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

Compliance Time

Within 100 hours time-in-service or 90 days after the effective date of this AD, whichever occurs later

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

Affected Aircraft

Learjet Model 55, 55B, and 55C airplanes; serial numbers 55-003 through 55-147, inclusive; certificated in any category.

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

Federal Register Abstract

Generator Wiring

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_93-24-10.html
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AD Number:
93-24-10
Document Type:
AD Final Rules
Docket Number:
93-NM-95-AD
Subject Heading:
Airworthiness Directives; Learjet Model 55, 55B, and 55C Airplanes
Subject:
Generator Wiring
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
01/18/1994
Make:
Learjet Inc.
Model:
55 | 55B | 55C
Product Type:
Aircraft
Product Subtype:
Small/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Superseded AD: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Superseded By: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: 93-24-10
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   93-NM-95-AD

AMENDMENT:   39-8759

AD NUMBER:   93-24-10

SUBJECT HEADING:   Airworthiness Directives; Learjet Model 55, 55B, and 55C Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective January 18, 1994.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
93-24-10 LEARJET: Amendment 39-8759. Docket 93-NM-95-AD.

Applicability: Model 55, 55B, and 55C airplanes; serial numbers 55-003 through 55-147, inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the loss of both generators during flight, accomplish the following:

(a) Within 100 hours time-in-service or 90 days after the effective date of this AD, whichever occurs later, modify the wiring inside the left- and right-hand generator interface boxes and between these two boxes, and perform an operational test of the DC power distribution system in accordance with Learjet Service Bulletin SB 55-24-4, dated May 3, 1993.

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA, Small Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Wichita ACO.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita ACO.

(c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) The modification and operational test shall be done in accordance with Learjet Service Bulletin SB 55-24-4, dated May 3, 1993. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Learjet Corporation, Customer Services, P.O. Box 7707, Wichita, Kansas 67277-7707. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Small Airplane Directorate, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(e) This amendment becomes effective on January 18, 1994.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_93-24-10.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
93-24-10
Document Type:
AD Final Rules
Docket Number:
93-NM-95-AD
Subject Heading:
Airworthiness Directives; Learjet Model 55, 55B, and 55C Airplanes
Subject:
Generator Wiring
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
01/18/1994
Make:
Learjet Inc.
Model:
55 | 55B | 55C
Product Type:
Aircraft
Product Subtype:
Small/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: 93-24-10
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   93-NM-95-AD

AMENDMENT:   39-8759

AD NUMBER:   93-24-10

SUBJECT HEADING:   Airworthiness Directives; Learjet Model 55, 55B, and 55C Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective January 18, 1994.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
93-24-10 LEARJET: Amendment 39-8759. Docket 93-NM-95-AD.

Applicability: Model 55, 55B, and 55C airplanes; serial numbers 55-003 through 55-147, inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the loss of both generators during flight, accomplish the following:

(a) Within 100 hours time-in-service or 90 days after the effective date of this AD, whichever occurs later, modify the wiring inside the left- and right-hand generator interface boxes and between these two boxes, and perform an operational test of the DC power distribution system in accordance with Learjet Service Bulletin SB 55-24-4, dated May 3, 1993.

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA, Small Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Wichita ACO.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita ACO.

(c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) The modification and operational test shall be done in accordance with Learjet Service Bulletin SB 55-24-4, dated May 3, 1993. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Learjet Corporation, Customer Services, P.O. Box 7707, Wichita, Kansas 67277-7707. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Small Airplane Directorate, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(e) This amendment becomes effective on January 18, 1994.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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