{"id":"F2006B08289","name":"AD/CESSNA 400/101 Amdt 1 - Seat Back Reinforcing Strap","slug":"ad-cessna-400-101-amdt-1-seat-back-reinforcing-strap","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115615,"registerId":"commonwealth-F2006B08289-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/101 Amdt 1 - Seat Back Reinforcing Strap","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)  \nCessna 400 Series Aeroplanes\n\nAD/CESSNA 400/101\n\nAmdt 1\n\n  \nSeat Back Reinforcing Strap 7/94\n\nApplicability: Aeroplanes in the Serial Number ranges:\n\n401B0101 to 401B0221\n\n402B0354 to 402C1020\n\n414-0151 to 414A1212\n\n421B0101 to 421C1807\n\n425-0002 to 425-0236\n\nRequirement: Action in accordance with Cessna MEB 89-3 Rev 1 and CQB 90-7 as applicable.\n\nCompliance: Within 100 hours time in service after 1 April 1993 for all applicable models, except the model 425 which is, within 100 hours time in service after 23 June 1994.\n\nBackground: In Australia there is a history of seat back failure in the aircraft referred to in the MEB. The most recent being a total failure in IMC conditions, which in normal single pilot operation would have resulted in total loss of control near the ground.\n\nAmendment 1 changes the Applicability to include the model 425 which has similar seats. It also includes Revision 1 to the MEB which requires no further work.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 1 expands the AD's scope by adding the model 425 serial number range to the Applicability list, thereby increasing the set of aircraft required to comply. Amendment 1 also records that Revision 1 of the Cessna MEB is included and that the revision requires no further work. (Applicability; Amendment 1; Requirement)"},"complexity_factors":["Serial-number-specific applicability across multiple models (Applicability)","Cross-reference to external manufacturer documents (Cessna MEB 89-3 Rev 1 and CQB 90-7) rather than containing standalone technical instructions (Requirement)","Two distinct compliance date triggers (general date and separate date for model 425) (Compliance)","Regulatory amendment that expands applicability and notes a revision to the MEB (Amendment 1)","Safety-critical operational context cited (seat back failures in IMC), which raises urgency but not additional procedural complexity in the AD text itself (Background)"],"plain_english_summary":"This directive requires owners/operators of specified Cessna 400‑series serial numbers (including an expanded model 425 range) to carry out the seat‑back work mandated by Cessna MEB 89‑3 Rev 1 and CQB 90‑7, made compulsory by the regulator. Work must be completed within 100 hours TIS from the AD’s effective dates. It was issued after seat‑back failures—one a total failure in IMC—posed a potential loss‑of‑control risk; affected operators bear the cost and scheduling burden."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of the directive (seat back reinforcement for safety). It simply expands applicability to include one additional aircraft model (Cessna 425) that shares the same defect, and updates the technical reference to a revised version. This is a routine safety expansion, not a fundamental change in purpose."},"complexity_factors":["Very short document (under 300 words)","Only 5 defined serial number ranges for applicability","Single technical requirement referencing external documents (MEB 89-3 Rev 1, CQB 90-7)","Simple compliance deadline structure (100 hours time in service after fixed dates)","No nested exceptions or conditional logic — only one variant (model 425 has different date)","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or inspections on certain aircraft.\n\n**What it does:**\nOrders owners and operators of specific Cessna 400-series aeroplanes to install a reinforcing strap on seat backs to prevent them from breaking during flight.\n\n**Who it affects:**\nOwners and operators of Cessna models 401, 402, 414, 421, and 425 with specific serial numbers (listed in the document). These are typically small business or private aircraft.\n\n**What must be done:**\nFollow the technical instructions in two Cessna documents (MEB 89-3 Rev 1 and CQB 90-7) to reinforce the seat backs. This work must be completed within 100 hours of flying time after specific dates (1 April 1993 for most models; 23 June 1994 for model 425).\n\n**Why it matters:**\nSeat backs in these aircraft have a history of failing in flight. One failure occurred in poor weather (IMC — Instrument Meteorological Conditions), which nearly caused a crash because the pilot lost control when the seat collapsed. This directive prevents potentially fatal accidents.\n\n**What's new in this version (Amendment 1):**\n- Adds the Cessna 425 model to the safety order (it has similar seats)\n- Updates to a revised technical document that confirms no additional work is needed beyond what's already required"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-101-amdt-1-seat-back-reinforcing-strap","history":"/api/acts/ad-cessna-400-101-amdt-1-seat-back-reinforcing-strap/history","analysis":"/api/acts/ad-cessna-400-101-amdt-1-seat-back-reinforcing-strap/analysis","conflicts":"/api/acts/ad-cessna-400-101-amdt-1-seat-back-reinforcing-strap/conflicts","importantCases":"/api/acts/ad-cessna-400-101-amdt-1-seat-back-reinforcing-strap/important-cases","documents":"/api/acts/ad-cessna-400-101-amdt-1-seat-back-reinforcing-strap/documents"}}