{"id":"F2006B09641","name":"AD/F100/4 - Thrust Reverser Door Bumper Fittings","slug":"ad-f100-4-thrust-reverser-door-bumper-fittings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54451,"registerId":"commonwealth-F2006B09641-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F100/4 - Thrust Reverser Door Bumper Fittings","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 F100 (F28 Mk 100) Series Aeroplanes\n\nAD/F100/4 Thrust Reverser Door Bumper Fittings 1/99\n\nApplicability: F28 Mk. 100 aircraft serial numbers 11244 through 11460, 11463 through 11469,\n\n11471, 11474, 11476, 11478 and 11479 and Grumman Aerospace part number (P/N) 1159P41440 spare aft engine cowlings, serial numbers (S/N) A0002 through A0031, S/N B0001 through B0020 (also identified as S/N 1001 through 1020) and S/N 1021 through 1220.\n\nRequirement: 1. Modify the thrust reverser doors in accordance with Fokker Service Bulletin F100- 78-010 dated 07 February 1994, and\n\n    2. Replace the Collins Multifunction Display Units (MFDUs) P/N 622-8047-412 or P/N 622-8047-422 with MFDU P/N 622-8047-414 or P/N 622-8047-423 as applicable, in accordance with Fokker SB F100-31-036 dated 07 February 1994.\n\n    3. Modify affected Grumman Aerospace spare aft cowlings P/N 115P41440 in accordance with Fokker Component SB P41440-78-02 dated 17 December 1993.\n\nNote: RLD Airworthiness Directive 94-062 (A) dated 29 April 1994 refers.\n\nCompliance: 1. Before accomplishment of 15,000 flight hours since new.\n\n    2. On completion of Requirement 1.\n\n    3. Prior to fitment to aircraft modified in accordance with Fokker SB F100-78-010 dated 07 February 1994.\n\nThis Airworthiness Directive becomes effective on 28 January 1999.\n\nBackground: The full scale fatigue test showed that the loads on the aircraft tail due to thrust reverser operation were higher than anticipated, resulting in a deteriorated fatigue life for the horizontal stabiliser main hinge fitting structure. This Directive is issued to reduce fatigue loads on the tail through modification of the thrust reverser doors and replacement of the multifunction display units incorporating software versions V7R1 or V8R1 as applicable.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive’s actions and specified affected items align with its stated safety objective to reduce tail loads and protect hinge fatigue life. It targets a defined subset of aircraft and spares rather than expanding to unrelated components."},"complexity_factors":["Narrow technical scope but multiple discrete actions: structural door modification, avionics (MFDU) replacement, plus component (cowling) modification (Requirements 1–3).","Detailed applicability by aircraft serial numbers and spare-part part/serial numbers increases record-checking and administrative tracking (Applicability).","Staggered compliance triggers (before 15,000 flight hours; on completion of Requirement 1; prior to fitment) require scheduling coordination across maintenance cycles (Compliance).","Work mixes airframe structural modification and avionics/software-related replacement, requiring different specialised skills, parts and approvals (Requirements 1–2).","Effective date and the need to retrofit existing spares before fitment create logistical and inventory costs for operators and parts suppliers (Compliance; Applicability).","Background links the measures to fatigue testing results, so demonstrating conformity to service bulletins is necessary for airworthiness documentation (Background; Requirement references to Fokker SBs)."],"plain_english_summary":"Requires owners/operators of specific Fokker F100 aircraft and listed Grumman spare aft cowlings to modify thrust reverser doors, replace certain Collins multifunction display units with newer part numbers, and modify spare cowlings. The stated aim is to reduce unexpectedly high tail loads and protect the horizontal stabiliser hinge’s fatigue life. Operators bear the cost and must complete work by the specified flight-hour or fitment deadlines to remain compliant."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific fatigue life issue identified in testing. The scope remains tightly focused on the original safety concern: reducing tail loads from thrust reverser operation through hardware and software modifications. No evidence of scope creep beyond the identified airworthiness issue."},"complexity_factors":["Multiple discrete requirements (3 separate technical modifications)","Specific part number and serial number applicability requiring cross-referencing","Interdependent compliance timing (Requirement 2 must follow Requirement 1)","Reference to external technical documents (3 separate Fokker Service Bulletins)","Cross-reference to related Dutch aviation authority directive (RLD AD 94-062)","Dual identification of serial numbers for spare cowlings (B-series also identified as 1000-series)"],"plain_english_summary":"This mandatory Airworthiness Directive orders owners/operators of specific Fokker F100 aeroplanes (and holders of certain Grumman spare aft engine cowlings) to implement three safety modifications: change thrust reverser doors, update certain cockpit display units, and alter specified spare engine cowlings before installation. \n\nTesting showed reverser use imposes higher loads that can fatigue the horizontal stabiliser hinge; the changes and software update reduce those loads and must be completed prior to 15,000 flight hours."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f100-4-thrust-reverser-door-bumper-fittings","history":"/api/acts/ad-f100-4-thrust-reverser-door-bumper-fittings/history","analysis":"/api/acts/ad-f100-4-thrust-reverser-door-bumper-fittings/analysis","conflicts":"/api/acts/ad-f100-4-thrust-reverser-door-bumper-fittings/conflicts","importantCases":"/api/acts/ad-f100-4-thrust-reverser-door-bumper-fittings/important-cases","documents":"/api/acts/ad-f100-4-thrust-reverser-door-bumper-fittings/documents"}}