{"id":"F2006B09902","name":"AD/F50/72 - Main Landing Gear Lock Link","slug":"ad-f50-72-main-landing-gear-lock-link","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55082,"registerId":"commonwealth-F2006B09902-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/72 - Main Landing Gear Lock Link","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)  Fokker F50 (F27 Mk 50) Series Aeroplanes\n\n \n\nAD/F50/72 Main Landing Gear Lock Link  3/97 DM\n\n \n\nApplicability: All serial numbers.\n\n \n\nRequirement: Unless already accomplished, action in accordance with Fokker SB F50-32-033.\n\n \n\nNote: Netherlands BLA nr: 1996-146(A) refers.\n\n \n\nCompliance: Within 7 days after 22 January 1997.\n\n \n\nThis Airworthiness Directive becomes effective on 22 January 1997.\n\n \n\nBackground: A MLG collapsed on roll out after landing. Investigation revealed that one of the two bolts that secure the downlock platform of the MLG locklink was missing. As a result of an AOT another operator reported broken lockwire and one of the affected bolts was loose. This unsafe condition if not corrected may result in further landing incidents.\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 standard, narrow airworthiness directive addressing a specific mechanical defect on a specific aircraft type. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 200 words)","Only 1 defined applicability criterion (all serial numbers)","Single requirement referencing external technical document (Fokker SB F50-32-033)","Simple compliance deadline (fixed date + 7 days)","No nested exceptions, conditional logic, or cross-references to other legislation","Straightforward causal chain in background section"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\nOrders all operators of **Fokker F50 aircraft** to inspect and fix a specific problem with the **main landing gear lock link** — a critical component that keeps the wheels locked in the down position during landing.\n\n**The safety problem:**\nA Fokker F50 suffered a collapsed landing gear after landing because a bolt was missing from the lock link mechanism. Another airline later found broken safety wire and a loose bolt on the same part. If not fixed, this could cause more landing gear collapses.\n\n**What operators must do:**\nFollow the repair instructions in **Fokker Service Bulletin F50-32-033** (a technical notice from the manufacturer). This involves checking and securing the bolts that hold the downlock platform.\n\n**Who it affects:**\nAll Fokker F50 aircraft operators in Australia — regardless of which specific plane they own (applies to all serial numbers).\n\n**Deadline:**\nWithin **7 days of 22 January 1997**.\n\n**Why it matters:**\nLanding gear collapse is extremely dangerous. This directive prevents accidents by forcing immediate inspection and repair of a known mechanical defect."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"Scope remains focused on correcting the specific unsafe condition described in the AD: missing/loose bolts and broken lockwire that contributed to a main landing gear collapse. The AD applies to all Fokker F50 serial numbers and mandates work per Fokker SB F50‑32‑033 within seven days of 22 January 1997 (Applicability; Requirement; Compliance). The Civil Aviation Safety Authority issued the directive under the Airworthiness Directives schedule; operators bear the cost and must perform the inspections/repairs (Requirement; Compliance)."},"complexity_factors":["Narrow technical scope — targets a specific component (main landing gear lock link) on a single aircraft type (Fokker F50). (Applicability)","Clear mandatory action — requires compliance with an identified manufacturer Service Bulletin (Fokker SB F50‑32‑033). (Requirement)","Short compliance window increases operational disruption risk — work required within 7 days of 22 Jan 1997. (Compliance)","Immediate safety trigger documented — follows an actual MLG collapse and related reports of loose/broken lockwire. (Background)","Low regulatory discretion — AD text leaves little room for alternative measures except 'unless already accomplished'. (Requirement)","Compliance burden concentrated on operators — inspection/repair labour, parts procurement and aircraft downtime are the direct costs. (Requirement / Compliance)","Reliance on external document (manufacturer SB) means operators must obtain and follow that SB; variation in repair complexity depends on SB content. (Requirement)","Recordkeeping and certification obligations implied by AD regime; potential scheduling and supply constraints for parts/maintenance resources."],"plain_english_summary":"This Airworthiness Directive orders operators of Fokker F50 (F27 Mk 50) aeroplanes to inspect and, if necessary, repair the main landing gear lock link using Fokker Service Bulletin F50‑32‑033. It applies to all serial numbers and must be done within seven days of 22 January 1997. The measure responds to a reported main‑gear collapse caused by a missing bolt and loose/broken lockwire; operators pay for and must schedule the corrective maintenance to avoid repeat incidents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-72-main-landing-gear-lock-link","history":"/api/acts/ad-f50-72-main-landing-gear-lock-link/history","analysis":"/api/acts/ad-f50-72-main-landing-gear-lock-link/analysis","conflicts":"/api/acts/ad-f50-72-main-landing-gear-lock-link/conflicts","importantCases":"/api/acts/ad-f50-72-main-landing-gear-lock-link/important-cases","documents":"/api/acts/ad-f50-72-main-landing-gear-lock-link/documents"}}