{"id":"F2006B07215","name":"AD/SWSA226/72 - Main Landing Gear Door Jamming","slug":"ad-swsa226-72-main-landing-gear-door-jamming","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48990,"registerId":"commonwealth-F2006B07215-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SWSA226/72 - Main Landing Gear Door Jamming","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)  \nFairchild (Swearingen) SA226 and SA227 Series Aeroplanes\n\nAD/SWSA226/72 Main Landing Gear Door Jamming 12/95 DM\n\nApplicability: Model SA226-T S/n T201 to T275, and T277 to T291; SA226-T(B) S/n T(B)276 and T(B)292 to T(B)417; SA226-AT S/n AT001 to AT074; and SA226-TC S/n TC201 to TC419.\n\nRequirement: 1. For aircraft with the MLG door stop installed in accordance with Fairchild Aircraft SB SA226-32-043 Revised 6 September 1983:\n\n\\- remove the four bolts P/N 27K51001-007 or the alternate P/N NAS 428-3-13 and four jam nuts P/N NAS509-3 from the P/N 27K51001-003 bracket assembly.\n\n2. For all applicable aircraft: service the MLG struts in accordance with “Fluid Servicing \\- Landing Gear” instructions in SA-226 Maintenance Manual 32-00-00 Paragraph 1C.\n\nNote: FAA AD 95-17-07 refers.\n\nCompliance: 1. Within 50 hours time in service after the effective date of this Directive.\n\n2. Unless carried out within the last 400 hours time in service, within 50 hours time in service after the effective date of this Directive.\n\nThis Directive has effect from 20 September 1995.\n\nBackground: There have been two incidents of aircraft making emergency MLG up landings when the MLG door stop bolts and striker plate hardware jammed and prevented the MLG from extending. Investigation revealed that misalignment of the bolts and the striker caused this jamming. This misalignment occurred because the strut did not fully extend upon gear retraction after the previous take off. This was caused by low hydraulic fluid in the strut.","sortOrder":0}],"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":3,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific mechanical failure mode. It has not expanded beyond its original purpose of preventing main landing gear door jamming incidents."},"complexity_factors":["Short, single-purpose directive with only 2 main requirements","Limited applicability scope (4 specific aircraft models with serial number ranges)","Simple conditional logic (only one 'if/then' condition for the bolt removal requirement)","One cross-reference to an FAA AD and one maintenance manual reference","No defined terms section or interpretation provisions","Straightforward compliance deadlines with basic time-in-service calculations"],"plain_english_summary":"This Airworthiness Directive affects owners, operators and maintenance crews of certain Fairchild Swearingen SA226/SA227 series aircraft (listed by serial number). It requires removal of four bolts/nuts from a main-gear door bracket and topping up hydraulic fluid in the main landing-gear struts.\n\nThe AD responds to two wheels-up emergency landings caused by gear-door jamming when low hydraulic fluid kept the strut from fully extending. Actions are mandatory within 50 flight hours after 20 September 1995."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive’s measures — removing specified door-stop hardware when fitted per the identified service bulletin and servicing landing-gear struts — align with the stated purpose of preventing MLG door jamming caused by bolt misalignment and low hydraulic fluid. It limits action to affected serial-numbered aircraft and to installations meeting the SB condition, so the scope is consistent with the safety issue described and does not broaden beyond that intent."},"complexity_factors":["Narrow applicability by model and serial numbers (Applicability section) reduces scope but requires checking individual airframe records.","Conditional requirement tied to whether the MLG door stop was installed in accordance with SB SA226-32-043 Rev 6 (Requirement 1) creates a prerequisite inspection burden.","Specific part-number removals (P/N 27K51001-007 or alternate NAS 428-3-13 and jam nuts P/N NAS509-3 from bracket P/N 27K51001-003) require parts-level identification and hands-on maintenance.","Mandatory servicing per SA-226 Maintenance Manual 32-00-00 Paragraph 1C (Requirement 2) relies on access to and compliance with the manual.","Short compliance windows (within 50 hours TIS; 400 hours TIS exception) impose scheduling and potential operational downtime costs (Compliance).","Safety-critical nature (Background: incidents involving emergency landings) increases regulatory enforcement and liability risk for operators.","Reference to FAA AD 95-17-07 introduces cross-jurisdictional alignment considerations for internationally operated aircraft."],"plain_english_summary":"This airworthiness directive requires operators of specified Fairchild (Swearingen) SA226/SA227 aeroplanes to remove particular main-landing-gear (MLG) door-stop bolts and jam nuts (when fitted per a named service bulletin) and to service the MLG struts per the maintenance manual. It responds to incidents where misaligned bolts and low hydraulic fluid in the strut caused MLG doors to jam and prevented gear extension.\n\nAircraft owners/operators pay for and perform the work within the stated 50‑hour windows; CASA enforces the requirement, changing maintenance practice and part configuration for affected aircraft."}},"importantCases":[],"_links":{"self":"/api/acts/ad-swsa226-72-main-landing-gear-door-jamming","history":"/api/acts/ad-swsa226-72-main-landing-gear-door-jamming/history","analysis":"/api/acts/ad-swsa226-72-main-landing-gear-door-jamming/analysis","conflicts":"/api/acts/ad-swsa226-72-main-landing-gear-door-jamming/conflicts","importantCases":"/api/acts/ad-swsa226-72-main-landing-gear-door-jamming/important-cases","documents":"/api/acts/ad-swsa226-72-main-landing-gear-door-jamming/documents"}}