AD 89-26-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Viking Air Limited | DHC-7-1 | Airworthiness Directives; Boeing Model DHC-7 Series Airplanes |
| aircraft | Viking Air Limited | DHC-7-100 | Airworthiness Directives; Boeing Model DHC-7 Series Airplanes |
| aircraft | Viking Air Limited | DHC-7-101 | Airworthiness Directives; Boeing Model DHC-7 Series Airplanes |
| aircraft | Viking Air Limited | DHC-7-102 | Airworthiness Directives; Boeing Model DHC-7 Series Airplanes |
| aircraft | Viking Air Limited | DHC-7-103 | Airworthiness Directives; Boeing Model DHC-7 Series Airplanes |
Unsafe Condition
Collapse of the main landing gear (MLG) due to failure of the MLG upper lock strut with part numbers 15707-3, 15707-5, 15707-7, or those that cannot be positively identified.
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Required Actions
Inspect MLG upper lock struts for part numbers within 50 hours time-in-service after the effective date. Reprotect parts with alodine 1200 and grey epoxy paint if part numbers are 15707-5 or 15707-7. Perform one-time NDT inspection and daily visual inspections for cracks if part number is 15707-3, both 15707-3 and 15707-5, or unidentifiable. Replace struts with P/N 15709-7 or 15709-9 within 90 days after the effective date. Alternate compliance may be approved by the FAA Manager.
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Compliance Time
Within 50 hours time-in-service after the effective date of this AD, and within 90 days after the effective date for replacements. Compliance with inspections and replacements must be done prior to further flight as specified.
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Affected Aircraft
Viking Air Limited Model DHC-7-1, DHC-7-100, DHC-7-101, DHC-7-102, DHC-7-103 airplanes certificated in any category.
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Federal Register Abstract
Main Landing Gear Struts
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_89-26-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 89-26-05 Document Type: AD Final Rules Docket Number: 89-NM-175-AD Subject Heading: Airworthiness Directives; Boeing Model DHC-7 Series Airplanes Subject: Main Landing Gear Struts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 01/14/1990 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: 89-26-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 89-NM-175-AD AMENDMENT: 39-6421 AD NUMBER: 89-26-05 SUBJECT HEADING: Airworthiness Directives; Boeing Model DHC-7 Series Airplanes ACTION: SUMMARY: DATES: Effective January 14, 1990. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 89-26-05 BOEING OF CANADA, LTD., DE HAVILLAND DIVISION: Amendment 39- 6421. Docket No. 89-NM-175-AD. Applicability: De Havilland Model DHC-7 series airplanes, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent possible collapse of a main landing gear (MLG) due to failure of the MLG upper lock strut, accomplish the following: A. Within 50 hours time-in-service after the effective date of this AD, inspect the left and right main MLG upper lock struts to determine the part number of the struts. Accomplish this inspection in accordance with de Havilland Alert Service Bulletin A7-32-93, dated January 30, 1989. B. If the part number is identified to be either 15707-5 or 15707-7 (subassembly P/N 15709-7 or 15709-9), the airplane may be returned to service after reprotecting the part with alodine solution number 1200 and grey epoxy paint. C. If the part number is 15707-3, or is both 15707-3 and 15707-5, or cannot be positively identified, prior to further flight, perform a one-time NDT inspection for cracks, in accordance with de Havilland Service Bulletin No. 7-32-21, Revision B, dated October 1, 1982; and thereafter perform a visual inspection for cracks prior to the first flight of each day. Upper lock struts with cracks must be replaced prior to further flight. D. Replacement with a P/N 15709-7 or 15709-9 upper lock strut subassembly (machined P/N 15707-5 or 15707-7), constitutes terminating action for the repetitive inspections required by paragraph C., above. E. Within 90 days after the effective date of this AD, replace upper lock struts having part number 15707-3, or both 15707-3 and 15707-5, or those that cannot be positively identified, with P/N 15709-7 or 15709-9 upper lock strut subassembly (machined P/N 15707-5 or 15707-7). This constitutes terminating action for the repetitive inspection requirements of this AD. F. 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, New York Aircraft Certification Office, FAA, New England Region. NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment and then send it to the Manager, New York Aircraft Certification Office. G. 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. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Canada, Ltd., de Havilland Division, Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or FAA, New England Region, New York Aircraft Certification Office, 181 South Franklin Avenue, Valley Stream, New York. This AD supersedes AD 80-17-13, Amendment 39-3885. This amendment (39-6421, AD 89-26-05) becomes effective on January 14, 1990. FOOTER:
Document Text
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AD Final Rules - DRS_89-26-05.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 89-26-05 Document Type: AD Final Rules Docket Number: 89-NM-175-AD Subject Heading: Airworthiness Directives; Boeing Model DHC-7 Series Airplanes Subject: Main Landing Gear Struts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 01/14/1990 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: 89-26-05 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: 89-NM-175-AD AMENDMENT: 39-6421 AD NUMBER: 89-26-05 SUBJECT HEADING: Airworthiness Directives; Boeing Model DHC-7 Series Airplanes ACTION: SUMMARY: DATES: Effective January 14, 1990. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 89-26-05 BOEING OF CANADA, LTD., DE HAVILLAND DIVISION: Amendment 39- 6421. Docket No. 89-NM-175-AD. Applicability: De Havilland Model DHC-7 series airplanes, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent possible collapse of a main landing gear (MLG) due to failure of the MLG upper lock strut, accomplish the following: A. Within 50 hours time-in-service after the effective date of this AD, inspect the left and right main MLG upper lock struts to determine the part number of the struts. Accomplish this inspection in accordance with de Havilland Alert Service Bulletin A7-32-93, dated January 30, 1989. B. If the part number is identified to be either 15707-5 or 15707-7 (subassembly P/N 15709-7 or 15709-9), the airplane may be returned to service after reprotecting the part with alodine solution number 1200 and grey epoxy paint. C. If the part number is 15707-3, or is both 15707-3 and 15707-5, or cannot be positively identified, prior to further flight, perform a one-time NDT inspection for cracks, in accordance with de Havilland Service Bulletin No. 7-32-21, Revision B, dated October 1, 1982; and thereafter perform a visual inspection for cracks prior to the first flight of each day. Upper lock struts with cracks must be replaced prior to further flight. D. Replacement with a P/N 15709-7 or 15709-9 upper lock strut subassembly (machined P/N 15707-5 or 15707-7), constitutes terminating action for the repetitive inspections required by paragraph C., above. E. Within 90 days after the effective date of this AD, replace upper lock struts having part number 15707-3, or both 15707-3 and 15707-5, or those that cannot be positively identified, with P/N 15709-7 or 15709-9 upper lock strut subassembly (machined P/N 15707-5 or 15707-7). This constitutes terminating action for the repetitive inspection requirements of this AD. F. 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, New York Aircraft Certification Office, FAA, New England Region. NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment and then send it to the Manager, New York Aircraft Certification Office. G. 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. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Canada, Ltd., de Havilland Division, Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or FAA, New England Region, New York Aircraft Certification Office, 181 South Franklin Avenue, Valley Stream, New York. This AD supersedes AD 80-17-13, Amendment 39-3885. This amendment (39-6421, AD 89-26-05) becomes effective on January 14, 1990. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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