{"id":"F2022L00572","name":"AD/DHC-8/55 Amdt 1 Horizontal Stabiliser Skin Disbonding Follow-up 7/2022","slug":"ad-dhc-8-55-amdt-1-horizontal-stabiliser-skin-disbonding-follow-up-7-2022","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":102393,"registerId":"commonwealth-F2022L00572-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"De Havilland Canada (Bombardier) DHC-8 S","sectionType":"part","heading":"De Havilland Canada (Bombardier) DHC-8 Series Aeroplanes","content":"# De Havilland Canada (Bombardier) DHC-8 Series Aeroplanes\n\n| AD/DHC-8/55 Amdt 1 | Horizontal Stabiliser SkinDisbonding Follow-up | 7/2022 |\n| ------------------ | ---------------------------------------------- | ------ |\n\n| Applicability: | All De Havilland Canada (DHC) DHC-8, Series 100 and 300 aircraft which have any horizontal stabilisers serial numbered CAP 003 through CAP 214 fitted.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. For Horizontal Stabilisers, Serial Numbers CAP 003 through CAP 050:Perform an Ultrasonic Bond Inspection of the upper and lower skin panels (part number 85510025 and 85510026) for disbonding as outlined in DHC Non-Destructive Testing Manual, PSM 1-8-7A, Part 4, Section 55-00-01, as in force on the commencement date of this AD.2. For Horizontal Stabilisers, Serial Numbers CAP 003 through CAP 214:Carry out the requirements stated in the Airworthiness Limitations List (AWL) of DHC Maintenance Program Manual PSM 1-8-7 (for series 100 aircraft) and AWL of DHC Maintenance Program Manual PSM 1-83-7 (for Series 300 aircraft), as in force on the commencement date of this AD.Note: Transport Canada AD CF-98-24 is the basis for this AD. |\n| Compliance:    | For requirement 11. Unless already accomplished within the 3 months before 5 December 1998; repeat between 12 and 14 months after the initial inspection.For requirement 22. a. For Horizontal Stabilisers Serial Number CAP 003 through CAP 050: Following the Compliance 1 repeat inspection, inspect within the next 2 years and thereafter at intervals not to exceed 2 years.2. b. For Horizontal Stabilisers Serial Numbers CAP 051 through CAP 214:i. Where a past inspection fell due in 1998, unless already accomplished, perform the inspection as scheduled and repeat thereafter at intervals not to exceed 2 years.ii. Where a past inspection fell due in 1999, unless already accomplished, repeat thereafter at intervals not to exceed 2 years. |\n\n|             | iii. Where a past inspection fell due after 1 January 2001, perform the inspection 1 year earlier and repeat thereafter at intervals not to exceed 2 years.Note: The inspection interval has been reduced from 3 years to 2 years in accordance with Temporary Revision (TR) No. 63 of the AWL in the DHC Maintenance Program Manual PSM 1-8-7 for series 100 aircraft and TR No. AWL 3-70 of the AWL for the DHC Maintenance Program Manual PSM 1-83-7 for the 300 series aircraft.For requirements 1 and 2Disbonds beyond the local disbond limits defined in DHC document PSM 1- 8 -7A, Part 4, Section 55-00-01, as in force from time to time, must be repaired before further flight.                              |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n|             | This AD commences on 15 April 2022.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |\n| Background: | As a result of the inspection required by AD/DHC-8/51, a total of four aircraft with serial numbers close together were determined to have disbonds of the doublers and stringers on the upper and lower skin panels of the horizontal stabiliser. This discovery indicates that the bonding process was defective on a single batch of skins. The follow-up inspections of this Directive will ensure that no further problems exist in the above single batch or other batches of the bonded skin panels.Amendment 1 of this AD updates references to DHC NDT manual PSM 1-8-7A from part 5 to part 4. Transport Canada has issued an associated global AMOC AARDG‑2016/A48, which is available upon request from DHC. |\n\n![Text\nDescription automatically generated](image.001.jpeg)\n\nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n7 April 2022","sortOrder":0},{"sectionNumber":"AD/DHC-8/55 Amdt 1","sectionType":"part","heading":"AD/DHC-8/55 Amdt 1","content":"## AD/DHC-8/55 Amdt 1","sortOrder":1},{"sectionNumber":"Horizontal Stabiliser SkinDisbonding Fol","sectionType":"part","heading":"Horizontal Stabiliser SkinDisbonding Follow-up","content":"## Horizontal Stabiliser Skin  \nDisbonding Follow-up","sortOrder":2},{"sectionNumber":"7/2022","sectionType":"part","heading":"7/2022","content":"## 7/2022","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"Amendment 1 updates a reference in the DHC NDT manual from Part 5 to Part 4 and notes an associated global AMOC; it does not change the AD's applicability, the required inspections, the repair-before-flight mandate, or the inspection interval as set out in the directive."},"complexity_factors":["Serial‑numbered applicability (CAP 003–CAP 214) creates split obligations: CAP 003–CAP 050 have an initial ultrasonic inspection requirement distinct from CAP 051–CAP 214.","Multiple linked documents: requirements and limits are defined across DHC NDT Manual PSM 1‑8‑7A (Part 4), DHC Maintenance Program Manual AWLs (PSM 1‑8‑7 and PSM 1‑83‑7) and Transport Canada AD CF‑98‑24.","Staggered compliance windows with historical due‑date rules (references to inspections due in 1998, 1999, after 1 Jan 2001) add retrospective scheduling complexity for operators.","Recurring inspection interval change from 3 years to 2 years (via Temporary Revisions) increases ongoing maintenance burden and recordkeeping.","Technical requirement (ultrasonic bond inspection) requires NDT capability and interpretation to DHC-defined local disbond limits; repairs mandatory before further flight if limits exceeded.","Cross-references to in-force versions of manuals introduce dependency on which edition is 'commencement date' applicable and on available AMOC (global alternative method) from the manufacturer."],"plain_english_summary":"This airworthiness directive requires ultrasonic inspections of upper and lower horizontal‑stabiliser skin panels and ongoing compliance with the Airworthiness Limitations Lists for De Havilland DHC‑8 Series 100 and 300 aeroplanes fitted with stabiliser serial numbers CAP 003–CAP 214. Disbonds that exceed the local limits in the DHC NDT manual must be repaired before further flight. It shortens the recurring inspection interval to two years and cites Transport Canada AD CF‑98‑24 and DHC maintenance manuals for procedures."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is Amendment 1 to an existing Airworthiness Directive. The amendment is narrow and technical — it updates a document reference from Part 5 to Part 4 of the NDT manual. The scope remains limited to the original safety issue (horizontal stabiliser skin disbonding on specific DHC-8 aircraft) and does not expand to new aircraft types, new structural components, or new operational requirements."},"complexity_factors":["Multiple serial number ranges with different compliance requirements (CAP 003–050 vs CAP 051–214)","Nested conditional logic for compliance dates based on when past inspections fell due (1998, 1999, or post-2001)","Cross-references to four separate technical documents (PSM 1-8-7A, PSM 1-8-7, PSM 1-83-7, plus Transport Canada AD CF-98-24)","Dual applicability tracks for Series 100 and Series 300 aircraft with different manual references","Incorporation of external Temporary Revisions (TR No. 63 and TR No. AWL 3-70) that change inspection intervals","Reference to an available but not included Alternative Method of Compliance (AMOC) from Transport Canada"],"plain_english_summary":"This CASA Airworthiness Directive mandates special inspections of horizontal stabilisers on De Havilland DHC-8 Series 100/300 aircraft with stabiliser serials CAP003–CAP214 after discovery of disbonding in a batch of parts. Operators must follow the tightened inspection schedule (including ultrasonic checks and reduced intervals) and must ground aircraft if disbonds exceed limits.\n\nThe amendment updates which maintenance manual section to use. The AD took effect 15 April 2022."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-55-amdt-1-horizontal-stabiliser-skin-disbonding-follow-up-7-2022","history":"/api/acts/ad-dhc-8-55-amdt-1-horizontal-stabiliser-skin-disbonding-follow-up-7-2022/history","analysis":"/api/acts/ad-dhc-8-55-amdt-1-horizontal-stabiliser-skin-disbonding-follow-up-7-2022/analysis","conflicts":"/api/acts/ad-dhc-8-55-amdt-1-horizontal-stabiliser-skin-disbonding-follow-up-7-2022/conflicts","importantCases":"/api/acts/ad-dhc-8-55-amdt-1-horizontal-stabiliser-skin-disbonding-follow-up-7-2022/important-cases","documents":"/api/acts/ad-dhc-8-55-amdt-1-horizontal-stabiliser-skin-disbonding-follow-up-7-2022/documents"}}