{"id":"F2009L02172","name":"AD/AT-6/2 Amdt 1 - Horizontal Stabliser Rear Spar Connector Fittings","slug":"ad-at-6-2-amdt-1-horizontal-stabliser-rear-spar-connector-fittings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":140324,"registerId":"commonwealth-F2009L02172-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Rockwell (N American) & Autair (Noorduyn","sectionType":"division","heading":"Rockwell (N American) & Autair (Noorduyn) AT-6, BC-1A, SNJ, T-6G, Harvard, & AT-16 Series Aeroplanes","content":"### Rockwell (N American) & Autair (Noorduyn) AT-6, BC-1A, SNJ, T-6G, Harvard, & AT-16 Series Aeroplanes\n\n| AD/AT-6/2 Amdt 1 | Horizontal Stabliser RearSpar Connector Fittings | 7/2009 |\n| ---------------- | ------------------------------------------------ | ------ |\n\n| Applicability: | All Model Harvard 2 and Harvard 4 aircraft and Model AT-6D (SNJ-5), AT-6F(SNJ-6), SNJ-7 and T-6G aircraft; equipped with single piece design horizontal stabiliser rear spar connector fittings, part number 7721021 (4 fittings per spar).This Directive is not applicable to aircraft equipped with two piece design connector fittings part numbers 77210213 and 77210214 (8 fittings per spar).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Remove the fuselage to vertical stabiliser fairing assembly and the rear fairing assemblies at the horizontal stabiliser.Remove the ¼-inch bolts which attach the upper and lower spar connection fittings part number 7721021, of the rear spar assembly.Remove the four connection fittings from the spar, remove the paint from the connection fittings, and check for cracks using dye penetrant inspection method. Replace any cracked fittings with serviceable fittings and repaint the fittings found to be crack free.Inspect the fit between the connection fittings and the spar with a feeler gauge before installation of the bolts. If gaps greater than 0.010-inches exist, shims are necessary.Fabricate aluminium shims 3 ⅛ -inch x 15/16 -inch and of necessary thickness, and place on either side of spar flanges, maintaining a parallel overall dimension to fit inside the connection fitting with a maximum clearance of 0.010-inches.Drill holes through the shims to match those of the fitting. Remove all drilling chips, and reinstall bolts and other removed parts in accordance with the aircraft maintenance manual.Note: Transport Canada AD CF-82-23 and FAA AD 81-14-10 refer. |\n| Compliance:    | Unless previously accomplished, before 31 July 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n|                | This Amendment becomes effective on 2 July 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |\n\n| Background: | The Canadian Airworthiness Authority required accomplishment of the requirements this Directive to detect cracking of the horizontal stabiliser rear spar connector fittings, and to check the fit of the connector fittings and the spar.Amendment 1 adds aircraft specified in FAA AD 81-14-10, which has the same requirements as this Directive, to the applicability section. This amendment is issued to ensure compliance of future imported aircraft. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n18 May 2009","sortOrder":0},{"sectionNumber":"AD/AT-6/2 Amdt 1","sectionType":"part","heading":"AD/AT-6/2 Amdt 1","content":"## AD/AT-6/2 Amdt 1","sortOrder":1},{"sectionNumber":"Horizontal Stabliser RearSpar Connector ","sectionType":"part","heading":"Horizontal Stabliser RearSpar Connector Fittings","content":"## Horizontal Stabliser Rear  \nSpar Connector Fittings","sortOrder":2},{"sectionNumber":"7/2009","sectionType":"part","heading":"7/2009","content":"## 7/2009","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"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"The original AD/AT-6/2 appears to have covered a narrower range of aircraft. Amendment 1 explicitly expands applicability to include additional aircraft models specified in FAA AD 81-14-10 (AT-6D/SNJ-5, AT-6F/SNJ-6, SNJ-7, and T-6G variants). The Background section confirms this expansion was specifically to 'ensure compliance of future imported aircraft' that were covered by the US directive but not previously captured by the Australian directive."},"complexity_factors":["Technical aviation terminology throughout (spar, fairing, dye penetrant inspection, feeler gauge)","Specific part number exclusions requiring careful identification (7721021 vs 77210213/77210214)","Precise dimensional tolerances (0.010-inch gap maximum, specific shim dimensions 3 ⅛-inch x 15/16-inch)","Multi-step procedural requirements with specific tool/method requirements","Cross-reference to foreign regulatory instruments (Transport Canada AD CF-82-23 and FAA AD 81-14-10)","Conditional logic: applicability depends on specific aircraft models AND specific part numbers AND design type (single vs two piece)"],"plain_english_summary":"This AD mandates owners/operators of specified vintage North American/Autair AT‑6/Harvard/SNJ/T‑6G aircraft with the single‑piece horizontal stabiliser rear spar connector fitting (p/n 7721021) to remove fairings, disassemble the fittings, strip paint and perform dye‑penetrant inspections; cracked parts must be replaced and oversized gaps shimmed. \n\nIt prevents catastrophic tail failure, aligns Australian requirements with a related FAA AD, and applied to affected aircraft before 31 July 2009."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Amendment 1 expands the directive's applicability by adding the aircraft specified in FAA AD 81‑14‑10 to ensure future imported aircraft are covered (see Background)."},"complexity_factors":["Technical inspection method required (dye‑penetrant) and subjective assessment of crack detection.","Tight dimensional tolerance: maximum clearance 0.010‑inches determines whether shims are needed.","Shim fabrication required to specific size (3 1/8\" x 15/16\") and thickness, plus drilling to match fitting holes.","Removal and reinstallation of fairings and rear spar components (access and procedural steps).","Multiple specific part numbers and an explicit exclusion (P/N 77210213 and 77210214) affecting applicability.","Cross‑references to Transport Canada AD CF‑82‑23 and FAA AD 81‑14‑10 (regulatory alignment and traceability).","Mandatory compliance date (before 31 July 2009) and stated effective date (2 July 2009).","Requirement to follow the aircraft maintenance manual for reassembly (delegated procedural detail to operators/maintainers)."],"plain_english_summary":"This directive requires owners/operators of specified Harvard and AT‑6 series aeroplanes fitted with single‑piece horizontal stabiliser rear‑spar connector fittings (P/N 7721021) to remove fairings, inspect the four fittings per spar using dye‑penetrant, replace any cracked fittings, check the fit with a feeler gauge, and fit aluminium shims where gaps exceed 0.010 in. Work must be done in accordance with the aircraft maintenance manual. Owners/operators bear the cost and must comply by 31 July 2009; the amendment extends applicability to additional FAA‑listed aircraft to cover future imports."}},"importantCases":[],"_links":{"self":"/api/acts/ad-at-6-2-amdt-1-horizontal-stabliser-rear-spar-connector-fittings","history":"/api/acts/ad-at-6-2-amdt-1-horizontal-stabliser-rear-spar-connector-fittings/history","analysis":"/api/acts/ad-at-6-2-amdt-1-horizontal-stabliser-rear-spar-connector-fittings/analysis","conflicts":"/api/acts/ad-at-6-2-amdt-1-horizontal-stabliser-rear-spar-connector-fittings/conflicts","importantCases":"/api/acts/ad-at-6-2-amdt-1-horizontal-stabliser-rear-spar-connector-fittings/important-cases","documents":"/api/acts/ad-at-6-2-amdt-1-horizontal-stabliser-rear-spar-connector-fittings/documents"}}