AD 76-14-01
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Viking Air Limited | DHC-4 | DeHavilland Model DHC-4 Series Airplanes |
| aircraft | Viking Air Limited | DHC-4A | DeHavilland Model DHC-4 Series Airplanes |
Unsafe Condition
Failure of rivets attaching hinge plates to outboard hinge arms on inboard trailing flap assemblies could lead to flap malfunction. Rudder rib failure could result in loss of rudder control. Electrofilm bearings in flap hinge arms may fail, causing flap system malfunction. External skin cracks on root fore flaps may indicate rib damage leading to structural failure. Loose terminal lug attachment to aluminum electrical cable assemblies could cause fire hazard. Main landing gear failure to fully extend and lock may result in landing gear collapse.
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Required Actions
Inspect and alter rivets per Engineering Bulletin DHC-4 No. 11. Inspect and alter rudder ribs per Modification Bulletin 4/1101. Inspect electrofilm bearings and replace with sintered bronze teflon lined bearings per Modification Bulletin 4/1099. Inspect root fore flaps for cracks and damage, remove and alter if required per Modification Bulletin 4/1150. Inspect, test, and replace aluminum electrical cables per Engineering Bulletin DHC-4 No. 18. Install spacer sleeve P/N 5735-5 into main landing gear assembly per Modification Bulletin 4/1182.
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Compliance Time
Within the next 50 hours' time in service after the effective date of this AD for items 1, 4(a), and 6(a). Within 100 hours' time in service for items 2(a) and 6(a). Within 250 hours' time in service for item 3(a). Repeat inspections at intervals not exceeding specified hours' time in service as per AD requirements.
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Affected Aircraft
DeHavilland Model DHC-4 and DHC-4A airplanes with serial numbers 2 through 17 (item 1), 2 through 22, 24, 25 (item 2), 2 through 39 except 23 and 28 (item 3), 1 through 43, 45-59 excluding specific serials (item 4), 4 through 57 excluding listed serials (item 5), and 2 through 38 except 23 and 34 (item 6), certificated in all categories, not altered per specified bulletins.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Inboard Trailing Flap Assemblies
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_76-14-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 76-14-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: DeHavilland Model DHC-4 Series Airplanes Subject: Inboard Trailing Flap Assemblies Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 07/12/1976 Make: Viking Air Limited Model: DHC-4 | DHC-4A 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: 76-14-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2661 AD NUMBER: 76-14-01 SUBJECT HEADING: DeHavilland Model DHC-4 Series Airplanes ACTION: SUMMARY: DATES: Effective July 12, 1976. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 76-14-01 DEHAVILLAND: Amendment 39-2661. 1. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 17, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Engineering Bulletin Series DHC-4 No. 11. Compliance required as indicated. Within the next 50 hours' time in service after the effective date of this AD, inspect and alter the rivets attaching the hinge plates to the outboard hinge arms on the inboard trailing flap assemblies in accordance with DeHavilland Engineering Bulletin Series DHC-4 No. 11 or with an equivalent inspection and alteration. 2. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 22, 24, and 25, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1101, Issue 4. Compliance required as indicated. (a) Within the next 100 hours' time in service after the effective date of this AD, inspect and alter the rudder ribs in accordance with DeHavilland Modification Bulletin No. 4/1101, Issue 4, or with an equivalent inspection and alteration. (b) Repeat the inspection noted in paragraph (a) above at intervals not to exceed 100 hours' time in service until the alteration in DeHavilland Modification Bulletin No. 4/1101, Issue 4, or an approved equivalent, has been incorporated. 3. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 39, except S/N 23 and 28, certificated in all categories that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1099, Issue 3. Compliance required as indicated. (a) Within the next 250 hours' time in service after the effective date of this AD, inspect all electrofilm "unibal" spherical bearings in the flap hinge arms in accordance with DeHavilland Modification Bulletin No. 4/1099, Issue 3, or with an equivalent inspection. (b) Repeat the inspection noted in paragraph (a) above at intervals not to exceed 250 hours' time in service until the replacement of all electrofilm bearings in the flap hinge arms has been accomplished with sintered bronze teflon lined unibal bearings in accordance with DeHavilland Modification Bulletin No. 4/1099, Issue 3, or with an equivalent alteration. 4. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 1 through 43, 45, 46, 47, 49, 50, 51, 53, 54, 55, 57, 58, and 59, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1150, Issue 3. Compliance required as indicated. (a) Within the next 50 hours' time in service after the effective date of this AD, inspect the left and right root fore flaps for external skin cracks if the flap has accumulated 300 hours' flying time. (b) Repeat the inspection noted in paragraph (a) above at intervals not to exceed 50 hours' time in service. (c) If the inspection indicated rib damage, or if the flap has accumulated 1000 hours' time in service, remove the flap and alter, before further flight, in accordance with DeHavilland Modification Bulletin No. 4/1150, Issue 3, or with an equivalent alteration. 5. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 4 through 57, except S/N 6, 13, 17, 21, 23, 26, 34, 40, 55, and 56, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada Ltd. Engineering Bulletin, Series DHC-4, No. 18. Compliance required as indicated. To preclude the possible hazard of a fire created by loose terminal lug attachment to the end of aluminum electrical cable assemblies, accomplish the following: (a) Within the next 200 hours' time in service after the effective date of this AD, inspect, test, and where necessary, replace aluminum electrical cable assemblies in accordance with DeHavilland Engineering Bulletin, Series DHC-4, No. 18 or with an equivalent inspection and test. 6. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 38, except S/N 23 and 34, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1182, Issue 2. Compliance required as indicated. To prevent possible failure of the main landing gear to fully extend and lock, accomplish the following: (a) Within the next 100 hours' time in service after the effective date of this AD, install a spacer sleeve, P/N 5735-5, into the upper end fitting, P/N 5705-5, of the main landing gear shortening mechanism assembly, P/N 5700-7, in accordance with DeHavilland Modification Bulletin No. 4/1182, Issue 2, or with an equivalent alteration. Equivalent parts, inspections, procedures, instructions, repairs and alterations must be approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, may adjust the inspection time in this Airworthiness Directive. Compliance with the Airworthiness Directive must be noted in the log book of the aircraft by referencing the Airworthiness Directive number and the specific item complied with: i.e. AD 76 - - - (4) if item 4 is being complied with. This amendment is effective July 12, 1976. FOOTER:
Document Text
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AD Final Rules - DRS_76-14-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 76-14-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: DeHavilland Model DHC-4 Series Airplanes Subject: Inboard Trailing Flap Assemblies Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 07/12/1976 Make: Viking Air Limited Model: DHC-4 | DHC-4A 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: 76-14-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-2661 AD NUMBER: 76-14-01 SUBJECT HEADING: DeHavilland Model DHC-4 Series Airplanes ACTION: SUMMARY: DATES: Effective July 12, 1976. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 76-14-01 DEHAVILLAND: Amendment 39-2661. 1. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 17, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Engineering Bulletin Series DHC-4 No. 11. Compliance required as indicated. Within the next 50 hours' time in service after the effective date of this AD, inspect and alter the rivets attaching the hinge plates to the outboard hinge arms on the inboard trailing flap assemblies in accordance with DeHavilland Engineering Bulletin Series DHC-4 No. 11 or with an equivalent inspection and alteration. 2. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 22, 24, and 25, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1101, Issue 4. Compliance required as indicated. (a) Within the next 100 hours' time in service after the effective date of this AD, inspect and alter the rudder ribs in accordance with DeHavilland Modification Bulletin No. 4/1101, Issue 4, or with an equivalent inspection and alteration. (b) Repeat the inspection noted in paragraph (a) above at intervals not to exceed 100 hours' time in service until the alteration in DeHavilland Modification Bulletin No. 4/1101, Issue 4, or an approved equivalent, has been incorporated. 3. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 39, except S/N 23 and 28, certificated in all categories that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1099, Issue 3. Compliance required as indicated. (a) Within the next 250 hours' time in service after the effective date of this AD, inspect all electrofilm "unibal" spherical bearings in the flap hinge arms in accordance with DeHavilland Modification Bulletin No. 4/1099, Issue 3, or with an equivalent inspection. (b) Repeat the inspection noted in paragraph (a) above at intervals not to exceed 250 hours' time in service until the replacement of all electrofilm bearings in the flap hinge arms has been accomplished with sintered bronze teflon lined unibal bearings in accordance with DeHavilland Modification Bulletin No. 4/1099, Issue 3, or with an equivalent alteration. 4. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 1 through 43, 45, 46, 47, 49, 50, 51, 53, 54, 55, 57, 58, and 59, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1150, Issue 3. Compliance required as indicated. (a) Within the next 50 hours' time in service after the effective date of this AD, inspect the left and right root fore flaps for external skin cracks if the flap has accumulated 300 hours' flying time. (b) Repeat the inspection noted in paragraph (a) above at intervals not to exceed 50 hours' time in service. (c) If the inspection indicated rib damage, or if the flap has accumulated 1000 hours' time in service, remove the flap and alter, before further flight, in accordance with DeHavilland Modification Bulletin No. 4/1150, Issue 3, or with an equivalent alteration. 5. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 4 through 57, except S/N 6, 13, 17, 21, 23, 26, 34, 40, 55, and 56, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada Ltd. Engineering Bulletin, Series DHC-4, No. 18. Compliance required as indicated. To preclude the possible hazard of a fire created by loose terminal lug attachment to the end of aluminum electrical cable assemblies, accomplish the following: (a) Within the next 200 hours' time in service after the effective date of this AD, inspect, test, and where necessary, replace aluminum electrical cable assemblies in accordance with DeHavilland Engineering Bulletin, Series DHC-4, No. 18 or with an equivalent inspection and test. 6. DeHavilland: Applies to DeHavilland Model DHC-4 Series Airplanes, S/N 2 through 38, except S/N 23 and 34, certificated in all categories, that have not been altered in accordance with DeHavilland Aircraft of Canada, Ltd. Modification Bulletin No. 4/1182, Issue 2. Compliance required as indicated. To prevent possible failure of the main landing gear to fully extend and lock, accomplish the following: (a) Within the next 100 hours' time in service after the effective date of this AD, install a spacer sleeve, P/N 5735-5, into the upper end fitting, P/N 5705-5, of the main landing gear shortening mechanism assembly, P/N 5700-7, in accordance with DeHavilland Modification Bulletin No. 4/1182, Issue 2, or with an equivalent alteration. Equivalent parts, inspections, procedures, instructions, repairs and alterations must be approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, may adjust the inspection time in this Airworthiness Directive. Compliance with the Airworthiness Directive must be noted in the log book of the aircraft by referencing the Airworthiness Directive number and the specific item complied with: i.e. AD 76 - - - (4) if item 4 is being complied with. This amendment is effective July 12, 1976. FOOTER:
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