{"id":"F2006B09807","name":"AD/F28/73 Amdt 1 - Passenger Door Lock Warning System","slug":"ad-f28-73-amdt-1-passenger-door-lock-warning-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54729,"registerId":"commonwealth-F2006B09807-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F28/73 Amdt 1 - Passenger Door Lock Warning System","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)  \nFokker F28 Series Aeroplanes\n\nAD/F28/73\n\nAmdt 1\n\n  \nPassenger Door Lock Warning System 10/93\n\nApplicability: All Model F28 (except Mk 0100), all serial numbers which have Service Bulletin F28/52-72 incorporated.\n\nRequirement: Action in accordance with Fokker SB F28/52-101 dated 1 November 1988 or Revision 1 dated 24 August 1992.\n\nNote: RLD AD 92-117/2 (A) dated 12 July 1993 refers.\n\nCompliance: The original compliance was prior to 4 September 1993. The compliance for this issue is prior to 1 November 1993.\n\nBackground: For some time, incidents have been reported of passenger doors opening shortly after take-off. In each case, an improperly locked door was left unobserved by cabin crews, while flight crews probably overlooked the DOOR UNLOCKED warning light during their pre-flight checks.\n\nIn 1988 Fokker issued service Bulletin F28/52-101 to improve the passengers door lock warning system. All the incidents occurred on aircraft on which this particular improvement had not been incorporated. Although the existing door lock warning system should be adequate, a recent incident, in which a door opened at 21,000 feet, prompted another review of the system. Fokker considers that all occurrences could have been avoided if this modification had been accomplished.\n\nThe RLD and CAA concur with this view and since the unsafe condition described may exist or develop on other aircraft of the same type design, this Airworthiness Directive requires the modification of the passenger door lock warning system.\n\nThis amendment is issued following the amendment of the RLD Airworthiness Directive and changes the applicability to aircraft in a post SB F28/52-72 configuration.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"This amendment narrows the scope compared to the original directive. The original AD applied more broadly, but Amendment 1 restricts applicability to only those aircraft that have already had Service Bulletin F28/52-72 incorporated. This excludes aircraft without that prior modification, likely because the safety issue manifests differently or requires a different solution on those airframes."},"complexity_factors":["Short, single-purpose directive (approximately 250 words)","Only 4 defined elements: applicability, requirement, note, and compliance","Single cross-reference to Dutch aviation authority directive (RLD AD 92-117/2)","Simple conditional logic: applies to 'all Model F28 (except Mk 0100)' with specific service bulletin incorporated","No nested exceptions or layered definitions","Clear, narrative background section explaining safety rationale"],"plain_english_summary":"This AD mandates upgrading the passenger door lock warning system on Fokker F28 series aeroplanes (excluding Mk 0100) using the specified Fokker Service Bulletin. It applies only to aircraft that already have Service Bulletin F28/52-72 installed and must be completed by 1 November 1993.  \n\nThe change responds to incidents of doors opening shortly after take-off and improves warnings to prevent in-flight door opening, rapid decompression, and crew/passenger endangerment."},"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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"The amendment alters the AD’s applicability to target aircraft in a post‑Service Bulletin F28/52‑72 configuration (i.e. those with SB F28/52‑72 incorporated), rather than the prior applicability. This shifts the compliance population and therefore which operators must carry the retrofit, as stated in the 'Applicability' and the amendment note (final sentence)."},"complexity_factors":["Applicability condition restricts affected fleet to F28 models (except Mk 0100) with Service Bulletin F28/52‑72 incorporated — (Applicability).","Mandated technical action is to follow a manufacturer service bulletin (Fokker SB F28/52‑101 or Revision 1), creating reliance on the manufacturer’s instructions for design and labour inputs — (Requirement).","Fixed compliance deadlines (originally prior to 4 Sep 1993; current issue prior to 1 Nov 1993) impose scheduling pressure on operators and maintenance providers — (Compliance).","Directive is prompted by safety incidents of doors opening after take-off, which sets a clear safety justification but limits discretion for alternative means of compliance — (Background).","This amendment explicitly changes applicability to aircraft in a post SB F28/52‑72 configuration, altering which serials must comply and therefore shifting who bears the retrofit cost — (final sentence).","Reference to the RLD AD and concurrence of RLD and CAA indicates multi‑jurisdictional coordination and potential for overlapping regulatory action or record checks — (Note; Background).","Implementation requires hands‑on modification of onboard warning systems, so operator costs include parts, labour, downtime and possible ordering lead times — (Requirement; Compliance).","Enforcement and certification are through the Civil Aviation Safety Authority’s AD schedule, implying an administrative compliance and recordkeeping burden for operators — (header and Schedule of Airworthiness Directives)."],"plain_english_summary":"This Airworthiness Directive requires operators of specified Fokker F28 aircraft (all models except Mk 0100 that have Service Bulletin F28/52‑72 incorporated) to modify the passenger door lock warning system in accordance with Fokker Service Bulletin F28/52‑101 (or Revision 1).\n\nIt is issued after incidents of doors opening shortly after take-off, sets a retrofit deadline (original compliance before 4 Sep 1993; this issue before 1 Nov 1993), and places the cost, scheduling and compliance burden on aircraft operators to maintain the aircraft’s airworthiness."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f28-73-amdt-1-passenger-door-lock-warning-system","history":"/api/acts/ad-f28-73-amdt-1-passenger-door-lock-warning-system/history","analysis":"/api/acts/ad-f28-73-amdt-1-passenger-door-lock-warning-system/analysis","conflicts":"/api/acts/ad-f28-73-amdt-1-passenger-door-lock-warning-system/conflicts","importantCases":"/api/acts/ad-f28-73-amdt-1-passenger-door-lock-warning-system/important-cases","documents":"/api/acts/ad-f28-73-amdt-1-passenger-door-lock-warning-system/documents"}}