{"id":"F2009L00737","name":"AD/CESSNA 400/118 - Auxiliary Wing Spars","slug":"ad-cessna-400-118-auxiliary-wing-spars","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":77682,"registerId":"commonwealth-F2009L00737-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Cessna 400 Series Aeroplanes","sectionType":"division","heading":"Cessna 400 Series Aeroplanes","content":"### Cessna 400 Series Aeroplanes\n\n| AD/CESSNA 400/118 | Auxiliary Wing Spars | 4/2009 DM |\n| ----------------- | -------------------- | --------- |\n\n| Applicability: | Model 401 aircraft, serial numbers 655 and 401-0001 through 401-0322.Model 401A aircraft, serial numbers 655 and 401A0001 through 401A0132.Model 401B aircraft, serial numbers 401B0001 through 401B0221.Model 402 aircraft, serial numbers 402-0001 through 402-0322.Model 402A aircraft, serial numbers 402A0001 through 402A0129.Model 402B aircraft, serial numbers 402B0001 through 402B0122, 402B0201 through 402B0249, 402B0301 through 402B0455, 402B0501 through 402B0640, 402B0801 through 402B0935, 402B1001 through 402B1100, 402B1201 through 402B1250, and 402B1301 through 402B1384.                                                                                                                                                                                                                                                                                                                                                                                                                                                               |\n| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Visually inspect the auxiliary wing spar near the location where the main landing gear trunnion is mounted, for cracks; in accordance with Cessna Service BulletinMEB08-8 original issue, or later FAA approved revision.If any crack is detected during any inspection that is 0.5-inch or more, before further flight, replace the cracked part(s).If any cracks are detected during any inspection that are less than 0.5-inch, accomplish the following:Repetitively inspect the crack(s) for length at intervals not to exceed 50 hours time in service and, before further flight, replace any part that has a crack with a length of 0.50-inch or more; and,Replace the cracked part within 200 hours time in service after the original crack was detected, or within 12 months after the original crack was detected, whichever occurs first.If cracks are detected as a result of any inspection, report the results to the Cessna Aircraft Company at whichever of the following occurs later:Within 10 days after the inspection is accomplished; or, |\n\n|             | Within the next 10 days after 2 March 2009.Note 1: Supplemental Inspection Numbers 57-10-09 and 57-10-13 of the Cessna 401/402 Supplemental Inspection Document (SID) inspect the auxiliary spar caps, but not the webs. Hence, this Airworthiness Directive applies even to SID-compliant aircraft.Note 2: FAA AD 2009-04-04 Amdt 39-15810.                                            |\n| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | Accomplish the initial inspection within 10 hours time in service after 2 March 2009, unless already accomplished; and, in addition, before further flight anytime the aircraft experiences a hard landing. Inspect thereafter if cracking is detected, as specified in the Requirement section of this Directive.                                                                      |\n|             | This Airworthiness Directive becomes effective on 2 March 2009.                                                                                                                                                                                                                                                                                                                         |\n| Background: | The FAA received several reports of fatigue cracking on Models 402A and 402B aircraft, in the area of the auxiliary wing spar where the main landing gear trunnion is mounted. This condition, unless corrected, could result in failure of the wing auxiliary spar web and cause landing gear collapse during normal landing. This could lead to loss of control and passenger injury. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n23 February 2009","sortOrder":0},{"sectionNumber":"AD/CESSNA 400/118","sectionType":"part","heading":"AD/CESSNA 400/118","content":"## AD/CESSNA 400/118","sortOrder":1},{"sectionNumber":"Auxiliary Wing Spars","sectionType":"part","heading":"Auxiliary Wing Spars","content":"## Auxiliary Wing Spars","sortOrder":2},{"sectionNumber":"4/2009 DM","sectionType":"part","heading":"4/2009 DM","content":"## 4/2009 DM","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The AD extends regulatory coverage beyond the existing Supplemental Inspection Document (SID) because SID Supplemental Inspection Numbers 57‑10‑09 and 57‑10‑13 inspected auxiliary spar caps but not the spar webs; the AD therefore applies even to SID‑compliant aircraft (Note 1). The directive thus broadens inspection scope to include webs and imposes new inspection, reporting and replacement obligations on operators of the listed serial numbers."},"complexity_factors":["Wide applicability listing many specific serial-number ranges across Model 401/401A/401B/402/402A/402B (Applicability section).","Clear numeric crack threshold (0.5 inch) that triggers immediate replacement (Requirement).","Repetitive-inspection regime for cracks under 0.5 inch: inspect every 50 hours TIS and replace if crack reaches 0.5 inch (Requirement).","Replacement deadline for detected cracks: within 200 hours TIS or within 12 months, whichever occurs first (Requirement).","Initial inspection scheduling: within 10 hours TIS after 2 March 2009 and before further flight after any hard landing (Compliance).","Reporting obligation to Cessna within specified 10‑day windows after inspection (Requirement).","Mandated use of Cessna Service Bulletin MEB08‑8 or later FAA‑approved revision as the inspection procedure (Requirement).","SID overlap issue: Note that existing Supplemental Inspection Document inspected spar caps but not webs, so AD applies even to SID‑compliant aircraft (Note 1).","Operational impact phrase 'before further flight' for cracks ≥0.5 inch imposes immediate out‑of‑service replacement costs (Requirement)."],"plain_english_summary":"This Airworthiness Directive requires operators of specified Cessna 400‑series Model 401/402 aircraft to visually inspect the auxiliary wing spar at the main landing‑gear trunnion for cracks and to replace parts meeting size or timing thresholds, following Cessna Service Bulletin MEB08‑8 (or later FAA‑approved revision). It is effective 2 March 2009.\n\nThe AD aims to address fatigue cracking that can cause spar failure and landing‑gear collapse. It creates inspection, reporting and replacement obligations, short recurring inspection intervals for detected cracks, and operator costs to comply."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with focused scope. It addresses a specific safety issue (fatigue cracking in auxiliary wing spars) for a defined fleet of aircraft. The scope remains tightly constrained to the original safety concern without expansion into unrelated operational or maintenance areas."},"complexity_factors":["Multiple aircraft models and extensive serial number ranges listed in applicability table","Conditional requirements based on crack size (0.5-inch threshold creates two distinct compliance paths)","Multiple compliance timeframes: initial (10 hours), repetitive (50 hours), replacement (200 hours or 12 months), and reporting (10 days)","Cross-reference to external documents: Cessna Service Bulletin MEB08-8 and FAA AD 2009-04-04","Exception logic: applies even to SID-compliant aircraft (Note 1)","Trigger-based compliance: 'hard landing' requires immediate inspection before further flight"],"plain_english_summary":"This AD requires owners/operators of specified Cessna 400-series aircraft to inspect the auxiliary wing spar near the main landing gear trunnion for fatigue cracks because reported cracking could lead to gear collapse and loss of control. Inspections must occur promptly (within 10 flight hours or after any hard landing); large cracks require part replacement before flight, smaller cracks need monitoring/replacement on a short schedule, and any cracking must be reported to Cessna. Compliance is mandatory even if following Cessna's SID."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-118-auxiliary-wing-spars","history":"/api/acts/ad-cessna-400-118-auxiliary-wing-spars/history","analysis":"/api/acts/ad-cessna-400-118-auxiliary-wing-spars/analysis","conflicts":"/api/acts/ad-cessna-400-118-auxiliary-wing-spars/conflicts","importantCases":"/api/acts/ad-cessna-400-118-auxiliary-wing-spars/important-cases","documents":"/api/acts/ad-cessna-400-118-auxiliary-wing-spars/documents"}}