{"id":"F2006B09806","name":"AD/F28/72 Amdt 1 - Elevator Gust Lock and Support Structure","slug":"ad-f28-72-amdt-1-elevator-gust-lock-and-support-structure","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54728,"registerId":"commonwealth-F2006B09806-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F28/72 Amdt 1 - Elevator Gust Lock and Support Structure","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/F28/72\n\nAmdt 1\n\n  \nElevator Gust Lock and Support Structure 7/93\n\nApplicability: Model F28 (except Mk. 0100), all serial numbers.\n\nRequirement: Inspect the elevator gust lock housing and support structure for cracks in accordance with the Accomplishment Instructions of Fokker Service Bulletin F28/55-30.\n\nNote 1: Compliance with Fokker SB F28/55-31 constitutes terminating action for the support structure inspections.\n\nNote 2: RLD AD 92-101/2 (A) refers.\n\nCompliance: As specified in the Requirement Document with an initial accomplishment time of 2 July 1993.\n\nThe compliance time of this Directive remains unchanged. This Amendment is effective from 24 June 1993.\n\nBackground: The failure of an elevator gustlock housing has been been reported. This event occurred during maintenance after the cockpit control column was moved with the gustlock ON and the hydraulic system activated. The support structure on which the housing is mounted was also damaged. Amendment 1 is issued to reflect a revision of the related RLD AD which was revised to allow a terminating action in lieu of inspections of the gustlock support structure.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is an amendment to an existing Airworthiness Directive, not an expansion of scope. Amendment 1 merely updates the original AD/F28/72 to reflect a revision in the referenced Dutch aviation authority directive (RLD AD 92-101/2). The change adds an option for terminating action (permanent fix) in lieu of repeated inspections, but does not expand the aircraft covered, the components affected, or the safety purpose. The scope remains limited to the original elevator gust lock housing and support structure inspections."},"complexity_factors":["Single, specific mechanical component targeted (elevator gust lock housing)","Only one model series affected with clear exclusion (F28 except Mk. 0100)","Two referenced documents (Fokker Service Bulletins) but no internal cross-references within the AD itself","No defined terms section","Simple conditional logic: comply by date OR use terminating action","Very short document (approximately 150 words of substantive text)","Single compliance pathway with one alternative (terminating action)"],"plain_english_summary":"CASA requires inspections of the elevator gust lock housing and its support structure on most Fokker F28 aircraft (all models except Mk. 0100) after a maintenance incident where the housing fractured when the control column was moved with the gust lock engaged. Undetected cracks could lead to structural failure and loss of control.\n\nCompliance follows Fokker Service Bulletin F28/55-30, with terminating action available via SB F28/55-31; this Amendment 1 aligns the AD with the Dutch RLD update."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 1 does not alter the aircraft applicability or the initial compliance date, but it adds an alternative compliance route: completing Fokker SB F28/55-31 is accepted as a terminating action for support-structure inspections (Note 1). In effect, the scope of ongoing inspection obligations is reduced for operators who implement the terminating action, while the core inspection requirement (per SB F28/55-30) and reporting of the original failure remain in force."},"complexity_factors":["Cross-reference to two Fokker Service Bulletins (F28/55-30 for inspections; F28/55-31 as a terminating action) creates dependency on external technical documents.","Technical nature of required inspections (crack detection) requires qualified maintenance personnel and judgement.","Conditional compliance path: inspections may be ended if terminating action is completed (Note 1), which changes ongoing obligations.","Reference to an unspecified 'Requirement Document' for timing and intervals introduces interpretation burden for operators.","Interaction with a related RLD AD (Note 2 and Background) requires regulatory coordination and tracking of foreign AD revisions.","Narrow applicability (Model F28 except Mk. 0100) but covering all serial numbers requires fleet-level compliance management."],"plain_english_summary":"This airworthiness directive requires operators of Fokker F28 aeroplanes (except Mk. 0100) to inspect the elevator gust-lock housing and its support structure for cracks, following Fokker Service Bulletin F28/55-30, with initial compliance by 2 July 1993.\n\nAfter a reported gust-lock housing failure during maintenance, the amendment allows operators to use Fokker SB F28/55-31 as a terminating action to end support-structure inspections (Note 1). The Civil Aviation Safety Authority issued the directive; operators pay for inspections and repairs."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f28-72-amdt-1-elevator-gust-lock-and-support-structure","history":"/api/acts/ad-f28-72-amdt-1-elevator-gust-lock-and-support-structure/history","analysis":"/api/acts/ad-f28-72-amdt-1-elevator-gust-lock-and-support-structure/analysis","conflicts":"/api/acts/ad-f28-72-amdt-1-elevator-gust-lock-and-support-structure/conflicts","importantCases":"/api/acts/ad-f28-72-amdt-1-elevator-gust-lock-and-support-structure/important-cases","documents":"/api/acts/ad-f28-72-amdt-1-elevator-gust-lock-and-support-structure/documents"}}