{"id":"F2006B08274","name":"AD/CESSNA 340/29 - Seat Back Reinforcing Strap","slug":"ad-cessna-340-29-seat-back-reinforcing-strap","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115587,"registerId":"commonwealth-F2006B08274-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 340/29 - Seat Back Reinforcing Strap","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Cessna 340 Series Aeroplanes\n\n \n\nAD/CESSNA 340/29 Seat Back Reinforcing Strap 4/93\n\nApplicability: S/N 340-0001 to 340A1817.\n\n \n\nRequirement: Action in accordance with Cessna MEB 89-3. Compliance:  Prior to 30 June 1993.\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\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific aircraft model. It has not expanded beyond its original purpose of mandating a seat back repair."},"complexity_factors":["Extremely short document — approximately 150 words of substantive content","Only one technical requirement (install reinforcing strap per Cessna MEB 89-3)","Single applicability criterion (serial number range)","Single compliance deadline with no conditional extensions or exceptions","No defined terms section — relies entirely on external reference to Cessna MEB 89-3","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","No nested conditions, exceptions, or alternative compliance methods"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific Cessna 340 aircraft.\n\n**What it requires:** Owners and operators of Cessna 340 series aeroplanes with serial numbers 340-0001 through 340A1817 must install a reinforcing strap on the seat backs. This must be done following instructions in Cessna Maintenance Engineering Bulletin (MEB) 89-3, and completed before 30 June 1993.\n\n**Why it matters:** The seat backs in these aircraft have a history of breaking — including one total failure that occurred in poor weather (IMC means \"Instrument Meteorological Conditions\" — flying in clouds or low visibility). In a single-pilot operation, this could cause the pilot to lose control of the aircraft near the ground, with potentially fatal consequences. The reinforcing strap prevents the seat from collapsing backward.\n\n**Who it affects:** Anyone operating the specified Cessna 340 aircraft in Australia — typically private owners, charter operators, or flying schools using these twin-engine piston aircraft."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies only to the stated serial-number range and requires the work set out in Cessna MEB 89-3 to be completed by 30 June 1993 (Applicability; Requirement; Compliance). The instrument does not broaden applicability, expand technical requirements beyond the referenced MEB, or add continuing obligations beyond the specified compliance action and date, so there is no indication in the text that the scope has changed from the directive’s stated purpose."},"complexity_factors":["Narrow applicability defined by a specific serial-number range (Applicability)","Mandatory compliance with an external manufacturer engineering bulletin rather than detailed technical steps in the directive itself (Requirement)","Fixed compliance deadline compresses implementation timing and increases short-term scheduling complexity (Compliance)","Safety-critical subject matter increases the consequences of non-compliance, requiring formal maintenance processes and potential regulatory oversight (Background; Requirement)","Limited procedural detail in the AD means implementers must obtain and interpret the referenced MEB, adding an information-access step"],"plain_english_summary":"This directive requires owners/operators of Cessna 340 aeroplanes S/N 340-0001 through 340A1817 to carry out the corrective work specified in Cessna MEB 89-3 by 30 June 1993 to address a history of seat-back failures (including a recent total failure in IMC).  \n\nIt affects aircraft owners, operators and maintenance organisations, shifts compliance costs to owners, and creates short-term demand for authorised maintenance to meet the safety deadline."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-340-29-seat-back-reinforcing-strap","history":"/api/acts/ad-cessna-340-29-seat-back-reinforcing-strap/history","analysis":"/api/acts/ad-cessna-340-29-seat-back-reinforcing-strap/analysis","conflicts":"/api/acts/ad-cessna-340-29-seat-back-reinforcing-strap/conflicts","importantCases":"/api/acts/ad-cessna-340-29-seat-back-reinforcing-strap/important-cases","documents":"/api/acts/ad-cessna-340-29-seat-back-reinforcing-strap/documents"}}