AD 91-18-20

final rule

Airworthiness Directives; Boeing Of Canada, Ltd., De Havilland Division DHC-7 Series Airplanes

AD Number
91-18-20
Status
final_rule
Effective Date
Product Category
aircraft
Docket
91-NM-41-AD
FR Citation
This information is not available.
Technical illustration of an aircraft landing gear and wheel assembly
Problem area Landing gear

Applicability

TypeManufacturerModelDetails
aircraft Viking Air Limited DHC-7-1 Airworthiness Directives; Boeing Of Canada, Ltd., De Havilland Division DHC-7 Series Airplanes
aircraft Viking Air Limited DHC-7-100 Airworthiness Directives; Boeing Of Canada, Ltd., De Havilland Division DHC-7 Series Airplanes
aircraft Viking Air Limited DHC-7-101 Airworthiness Directives; Boeing Of Canada, Ltd., De Havilland Division DHC-7 Series Airplanes
aircraft Viking Air Limited DHC-7-102 Airworthiness Directives; Boeing Of Canada, Ltd., De Havilland Division DHC-7 Series Airplanes
aircraft Viking Air Limited DHC-7-103 Airworthiness Directives; Boeing Of Canada, Ltd., De Havilland Division DHC-7 Series Airplanes

Unsafe Condition

Failure of the main landing gear (MLG) due to cracking in the upper drag strut assembly.

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

Required Actions

Remove each MLG upper drag strut assembly and perform a non-destructive test. Overhaul the assembly if no cracking is found before further flight. Replace the assembly if cracking is evident before further flight. Compliance must follow Menasco Canada, Ltd. Service Bulletin No. 32-18, Revision 1.

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

Compliance Time

Within one year after the effective date of this AD

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

Affected Aircraft

Boeing Of Canada, Ltd., De Havilland Division DHC-7 series airplanes, Serial Numbers 1 through 27

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

Federal Register Abstract

Main Landing Gear

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_91-18-20.html
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AD Number:
91-18-20
Document Type:
AD Final Rules
Docket Number:
91-NM-41-AD
Subject Heading:
Airworthiness Directives; Boeing Of Canada, Ltd., De Havilland Division DHC-7 Series Airplanes
Subject:
Main Landing Gear
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
10/15/1991
Make:
Viking Air Limited
Model:
DHC-7-1 | DHC-7-100 | DHC-7-101 | DHC-7-102 | DHC-7-103
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: 91-18-20
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   91-NM-41-AD

AMENDMENT:   39-8024

AD NUMBER:   91-18-20

SUBJECT HEADING:   Airworthiness Directives; Boeing Of Canada, Ltd., De Havilland Division DHC-7 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective October 15, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
91-18-20 BOEING OF CANADA, LTD., DE HAVILLAND DIVISION: Amendment 39- 8024. Docket No. 91-NM-41-AD.

Applicability: Model DHC-7 series airplanes, Serial Numbers 1 through 27, certificated in any category.

Compliance: Required, as indicated, unless previously accomplished.

To prevent a possible failure of the main landing gear (MLG), accomplish the following:

(a) Within one year after the effective date of this AD, remove each MLG upper drag strut assembly from the airplane and perform a non-destructive test in accordance with the Accomplishment Instructions, paragraphs 2.D.(1) through (3), of Menasco Canada, Ltd., Service Bulletin No. 32-18, Revision 1, dated June 5, 1980.

(1) If there is no evidence of cracking, prior to further flight, overhaul the assembly in accordance with the Accomplishment Instructions, paragraph 2.D.(4), of the service bulletin.

(2) If cracking is evident, prior to further flight, replace the assembly with a serviceable part, in accordance with the service bulletin.

NOTE: The Menasco Canada, Ltd., Service Bulletin references Menasco Mfg. Component Maintenance Manual 32-10-16, dated September 1, 1976, as an additional source of service information for performing overhaul procedures.

NOTE: In the referenced Menasco Component Maintenance Manual, procedures are found only for "Repair." For this application, repair is equivalent to overhaul.

(b) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, New York Aircraft Certification Office (ACO), ANE-170, FAA, New England Region.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Standardization Branch, ANM-113.

(c) Special flight permits may be issued in accordance with FARs 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

(d) The inspection, overhaul, and replacement requirements shall be done in accordance with Menasco Canada, Ltd., Service Bulletin No. 32-18, Revision 1, dated June 5, 1980. 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 Boeing of Canada, Ltd., de Havilland Division, Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; at the FAA, New England Region, New York Aircraft Certification Office, 181 South Franklin Avenue, Room 202, Valley Stream, New York; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.

This amendment (39-8024, AD 91-18-20) becomes effective on October 15, 1991.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_91-18-20.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
91-18-20
Document Type:
AD Final Rules
Docket Number:
91-NM-41-AD
Subject Heading:
Airworthiness Directives; Boeing Of Canada, Ltd., De Havilland Division DHC-7 Series Airplanes
Subject:
Main Landing Gear
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
10/15/1991
Make:
Viking Air Limited
Model:
DHC-7-1 | DHC-7-100 | DHC-7-101 | DHC-7-102 | DHC-7-103
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: 91-18-20
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   91-NM-41-AD

AMENDMENT:   39-8024

AD NUMBER:   91-18-20

SUBJECT HEADING:   Airworthiness Directives; Boeing Of Canada, Ltd., De Havilland Division DHC-7 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective October 15, 1991.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
91-18-20 BOEING OF CANADA, LTD., DE HAVILLAND DIVISION: Amendment 39- 8024. Docket No. 91-NM-41-AD.

Applicability: Model DHC-7 series airplanes, Serial Numbers 1 through 27, certificated in any category.

Compliance: Required, as indicated, unless previously accomplished.

To prevent a possible failure of the main landing gear (MLG), accomplish the following:

(a) Within one year after the effective date of this AD, remove each MLG upper drag strut assembly from the airplane and perform a non-destructive test in accordance with the Accomplishment Instructions, paragraphs 2.D.(1) through (3), of Menasco Canada, Ltd., Service Bulletin No. 32-18, Revision 1, dated June 5, 1980.

(1) If there is no evidence of cracking, prior to further flight, overhaul the assembly in accordance with the Accomplishment Instructions, paragraph 2.D.(4), of the service bulletin.

(2) If cracking is evident, prior to further flight, replace the assembly with a serviceable part, in accordance with the service bulletin.

NOTE: The Menasco Canada, Ltd., Service Bulletin references Menasco Mfg. Component Maintenance Manual 32-10-16, dated September 1, 1976, as an additional source of service information for performing overhaul procedures.

NOTE: In the referenced Menasco Component Maintenance Manual, procedures are found only for "Repair." For this application, repair is equivalent to overhaul.

(b) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, New York Aircraft Certification Office (ACO), ANE-170, FAA, New England Region.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Standardization Branch, ANM-113.

(c) Special flight permits may be issued in accordance with FARs 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

(d) The inspection, overhaul, and replacement requirements shall be done in accordance with Menasco Canada, Ltd., Service Bulletin No. 32-18, Revision 1, dated June 5, 1980. 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 Boeing of Canada, Ltd., de Havilland Division, Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; at the FAA, New England Region, New York Aircraft Certification Office, 181 South Franklin Avenue, Room 202, Valley Stream, New York; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.

This amendment (39-8024, AD 91-18-20) becomes effective on October 15, 1991.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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