{"id":"F2006B06925","name":"AD/SEATS/2 - Enviroform Fibreglass/Kevlar Reinforced Seats","slug":"ad-seats-2-enviroform-fibreglass-kevlar-reinforced-seats","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114806,"registerId":"commonwealth-F2006B06925-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SEATS/2 - Enviroform Fibreglass/Kevlar Reinforced Seats","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nSeats and Berths\n\nAD/SEATS/2 Enviroform Fibreglass/Kevlar Reinforced Seats 3/88\n\nApplicability: All Enviroform seats. These are normally fitted but not restricted to the following Cessna aircraft:\n\nModel Serial No.\n\nC.402B and C 402B1047 to 402C1020\n\nC.404 404-0001 to 404-0859\n\nC.421C 421C0055 to 421C1807\n\nC.F406 F406-0001 to F406-0021\n\nC.441 441-0001 to 441-0362.\n\nRequirement: Action in accordance with Cessna MEB 87-9, CAB 87-16 or CQB 87-5. Compliance: Within 100 hours time in service after 24 March 1988.\n\nBackground: These seats were the subject initially of AD/CESSNA 400/50 issued in 1977. Since that time these seats have been found retrofitted to other aircraft. Additionally Cessna are now further modifying the seats and have expanded the applicability to include further aircraft.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The Background explains that the AD updates an earlier directive (AD/CESSNA 400/50, 1977) because Enviroform seats were subsequently retrofitted into other aircraft and Cessna has modified the seats and expanded the models/serial ranges covered. Mechanically, the current AD therefore broadens the set of aircraft subject to the mandatory actions by listing additional model/serial ranges and by directing compliance with updated Cessna documents. (Background; Applicability; Requirement)"},"complexity_factors":["Reference to external manufacturer documents (Cessna MEB 87-9, CAB 87-16, CQB 87-5) which require users to obtain and interpret another source (Requirement).","Serial-numbered applicability across multiple Cessna models requiring checking of individual airframes (Applicability).","Short, absolute compliance window (100 hours after a fixed date) compresses scheduling and increases near-term logistical complexity (Compliance).","Background history and retrofitting increases scope monitoring complexity because seats may be present in aircraft not originally listed (Background)."],"plain_english_summary":"What this instrument does (mechanics)\n\n- This is an Airworthiness Directive (AD) that requires specified actions to be carried out on Enviroform fibreglass/Kevlar reinforced seats. (Requirement)\n- The AD applies to all Enviroform seats and specifically lists serial-numbered ranges of Cessna models in which these seats are normally fitted. (Applicability)\n- It directs owners/operators to carry out the actions described in one of three Cessna technical documents: Cessna MEB 87-9, CAB 87-16 or CQB 87-5. (Requirement)\n- The actions must be completed within 100 hours time in service after 24 March 1988. (Compliance)\n\nWho is affected and what they must do\n\n- Aircraft owners/operators and maintenance organisations responsible for the listed Cessna models (and any aircraft fitted with Enviroform seats) must implement the specified Cessna procedures. (Applicability; Requirement)\n- The AD sets a short compliance window (100 hours time in service) measured from a fixed date, which determines when the actions must be completed. (Compliance)\n\nWhy the AD was issued (official rationale and source text)\n\n- The AD traces back to an earlier directive (AD/CESSNA 400/50, 1977) and states that Enviroform seats have subsequently been found retrofitted into other aircraft. Cessna has modified the seats and expanded the makes/models to which the documents apply. The Background text presents these facts as the basis for the current AD. (Background)\n\nPractical implications, incentives and trade-offs (mechanisms, not verdicts)\n\n- Who decides: The AD (a regulatory instrument) prescribes the remedial actions; compliance is mandatory for owners/operators of affected aircraft as identified by the Applicability and Requirement sections. (Applicability; Requirement)\n- Who pays: The text requires owners/operators to carry out the Cessna-prescribed actions. That creates a direct compliance cost for those parties in the form of parts, labour, and aircraft downtime implied by the Requirement and Compliance provisions. (Requirement; Compliance)\n- Compliance burden and timing: The 100-hour time-in-service deadline after a fixed date compresses when work must be scheduled and may increase near-term maintenance demand for affected operators. (Compliance)\n- Reliance on manufacturer documents: The AD implements Cessna-authored procedures (MEB 87-9, CAB 87-16, CQB 87-5). That ties the regulatory requirement to manufacturer technical judgement and creates an operational dependence on those documents for what constitutes acceptable corrective action. (Requirement)\n- Implementation risk and discretion: The AD text specifies the actions must follow the named Cessna documents and sets the compliance window. The directive text does not set alternative procedures or provide wording about exemptions or alternative means of compliance; decisions about alternative methods (if allowed) would require separate regulatory handling not described in the AD. (Requirement; Compliance)\n- Effects on maintenance providers and markets: The AD will increase demand for the specific modification/action described, affecting where owners obtain service (manufacturer-authorised centres or independent maintainers capable of following the Cessna documents). The AD does not itself create or restrict commercial choices beyond mandating the actions described in the cited documents. (Requirement)\n\nSummary of trade-offs and opportunity costs to consider\n\n- The AD constrains operational flexibility by requiring a specific set of manufacturer procedures within a short time frame, imposing direct compliance costs and aircraft downtime on owners/operators. (Requirement; Compliance)\n- The stated background reason is that seats have been retrofitted to additional aircraft and Cessna has modified the seat design; the mechanism adopted is to mandate compliance with the manufacturer’s corrective documents for all listed applications. This transfers the technical remedy to the manufacturer’s specified work-scope while imposing the implementation cost and scheduling burden on aircraft operators. (Background; Requirement)\n\nSource citations\n\n- Applicability: lists affected models and serial number ranges. (Applicability)\n- Requirement: directs action in accordance with Cessna MEB 87-9, CAB 87-16 or CQB 87-5. (Requirement)\n- Compliance: sets deadline of within 100 hours time in service after 24 March 1988. (Compliance)\n- Background: references the 1977 AD/CESSNA 400/50, retrofitting of seats and further Cessna modifications/expanded applicability. (Background)"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"This AD explicitly expands the scope of the original 1977 directive (AD/CESSNA 400/50). The original only covered certain Cessna 400-series aircraft, but this version broadens applicability to include: (1) additional aircraft models where the seats were 'retrofitted' (installed after manufacture), and (2) further aircraft types as Cessna expanded their modification program. The scope grew from a model-specific fix to a seat-manufacturer-specific fix across multiple aircraft types."},"complexity_factors":["Short, single-purpose directive with one clear requirement","Only 4 defined applicability categories (aircraft models with serial number ranges)","Single cross-reference to external Cessna technical documents (MEB 87-9, CAB 87-16, CQB 87-5)","Simple compliance condition (time-based: 100 hours after specific date)","No nested exceptions or conditional logic — applies to all listed aircraft or none","Background section provides context but doesn't create additional legal obligations"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of certain aircraft to inspect or modify specific seats made by a company called Enviroform.\n\n**What it does:**\n- **Targets:** Fibreglass/Kevlar reinforced seats manufactured by Enviroform, typically found in specific Cessna aircraft models (including the 402B, 404, 421C, F406, and 441 series).\n- **Requires:** Aircraft owners must follow specific technical instructions from Cessna (referenced as MEB 87-9, CAB 87-16, or CQB 87-5 — these are manufacturer service bulletins) to address a safety issue with these seats.\n- **Deadline:** The work must be completed within 100 hours of flight time after 24 March 1988.\n\n**Why it matters:**\nThese seats were originally flagged for safety concerns back in 1977. Since then, the problem seats have turned up in more aircraft types than originally thought, and Cessna has developed additional modifications. This directive expands the original safety order to catch all affected aircraft and ensure the seats won't fail in a way that could injure passengers or crew during turbulence or an accident.\n\n**Who it affects:**\n- Owners and operators of the listed Cessna aircraft models\n- Maintenance engineers working on these aircraft\n- Anyone responsible for keeping these planes airworthy (legally safe to fly)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-seats-2-enviroform-fibreglass-kevlar-reinforced-seats","history":"/api/acts/ad-seats-2-enviroform-fibreglass-kevlar-reinforced-seats/history","analysis":"/api/acts/ad-seats-2-enviroform-fibreglass-kevlar-reinforced-seats/analysis","conflicts":"/api/acts/ad-seats-2-enviroform-fibreglass-kevlar-reinforced-seats/conflicts","importantCases":"/api/acts/ad-seats-2-enviroform-fibreglass-kevlar-reinforced-seats/important-cases","documents":"/api/acts/ad-seats-2-enviroform-fibreglass-kevlar-reinforced-seats/documents"}}