{"id":"F2006B08998","name":"AD/DHC-1/14 - Flap Hinge Arms - Inspection and Modification","slug":"ad-dhc-1-14-flap-hinge-arms-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52640,"registerId":"commonwealth-F2006B08998-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-1/14 - Flap Hinge Arms - Inspection and Modification","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nDe Havilland DHC-1 (Chipmunk) Series Aeroplanes\n\nAD/DHC-1/14 Flap Hinge Arms \\- Inspection and Modification\n\n  \n8/62\n\nApplicability: All models. Requirement: 1. Inspecting:\n\n    (a) Remove the flap centre hinge arms (P/N C1.W.353 and C1.W.354) and inspect internally for the presence of corrosion.\n\n    (b) Hinge arms in which small areas of shallow surface corrosion are present shall be cleaned internally by sand blasting (or other effective means) and coated with a suitable protective medium before further flight.\n\n    (c) Hinge arms corroded in excess of the limits specified above shall be replaced with serviceable items before further flight.\n\nNote: The internal inspection can be performed readily by inserting a 1/8 inch diameter intrascope or similar optical aid, through on of the 3/8 inch diameter holes in the base plate of the hinge arm. The hole may be elongated slightly to allow the probe of the intrascope to be inserted to the full depth of the hinge arm.\n\n2. Modification: Drill a 1/8 inch diameter drain hole in the lower surface of the hinge arm at a distance of 0.75 inch from the ball race centreline.\n\nCompliance: Inspection \\- At intervals not exceeding 12 months. Modification \\- Forthwith.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1829},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope targeting a specific safety-critical component (flap hinge arms) on a single aircraft type (DHC-1 Chipmunk). No expansion beyond the original corrosion prevention and detection purpose is evident."},"complexity_factors":["Specific technical measurements and aviation part numbers (e.g., 'P/N C1.W.353', '1/8 inch diameter')","Conditional maintenance logic distinguishing between acceptable minor surface corrosion and unacceptable excessive corrosion","Brief reference to Civil Aviation Regulations Part 39 framework"],"plain_english_summary":"This mandatory Airworthiness Directive requires owners, operators and maintenance engineers of De Havilland DHC‑1 Chipmunk aircraft to inspect flap centre hinge arms for internal corrosion and, where necessary, clean/repair or replace them to ensure airworthiness. It also mandates drilling a small drain hole in each hinge arm immediately to prevent water ingress. Inspections must be repeated yearly. The measure prevents hinge failure that could cause flap loss and loss of control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-1-14-flap-hinge-arms-inspection-and-modification","history":"/api/acts/ad-dhc-1-14-flap-hinge-arms-inspection-and-modification/history","analysis":"/api/acts/ad-dhc-1-14-flap-hinge-arms-inspection-and-modification/analysis","conflicts":"/api/acts/ad-dhc-1-14-flap-hinge-arms-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-dhc-1-14-flap-hinge-arms-inspection-and-modification/important-cases","documents":"/api/acts/ad-dhc-1-14-flap-hinge-arms-inspection-and-modification/documents"}}