{"id":"F2006L01059","name":"AD/F100/78 - NLG Door Uplock Bracket Assembly","slug":"ad-f100-78-nlg-door-uplock-bracket-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":58362,"registerId":"commonwealth-F2006L01059-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Fokker F100 (F28 Mk 100) Series Aeroplan","sectionType":"division","heading":"Fokker F100 (F28 Mk 100) Series Aeroplanes","content":"### Fokker F100 (F28 Mk 100) Series Aeroplanes\n\n| AD/F100/78 | NLG Door Uplock Bracket Assembly | 5/2006 |\n| ---------- | -------------------------------- | ------ |\n\n| Applicability: | Model F.28 Mk. 0070 and Mk. 0100 aircraft, all serial numbers.                                                                                                                                                                                                                                                                                                                                                                                                         |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Modify the Nose Landing Gear Door Uplock Bracket Assembly in accordance with the Accomplishment Instructions of Fokker Service Bulletin SBF100-32-143, dated 15 February 2006, or later EASA approved revision.Note: CAA-NL AD NL-2006-004 refers.                                                                                                                                                                                                                     |\n| Compliance:    | Within 4,000 flight hours after 11 May 2006.                                                                                                                                                                                                                                                                                                                                                                                                                           |\n|                | This Airworthiness Directive becomes effective on 11 May 2006.                                                                                                                                                                                                                                                                                                                                                                                                         |\n| Background:    | Two events have been reported of Fokker 100 aircraft, where the nose landing gear failed to extend in normal mode and problems in opening the nose landing gear doors were experienced, almost preventing extension in emergency (alternate) mode. Investigation revealed that the friction of the bearing in the roller of the nose landing gear door uplock bracket assembly was high, causing increased resistance in the mechanical system that unlocks the doors. |\n\n![](image.001.png)  \nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n31 March 2006","sortOrder":0},{"sectionNumber":"AD/F100/78","sectionType":"part","heading":"AD/F100/78","content":"## AD/F100/78","sortOrder":1},{"sectionNumber":"NLG Door Uplock Bracket Assembly","sectionType":"part","heading":"NLG Door Uplock Bracket Assembly","content":"## NLG Door Uplock Bracket Assembly","sortOrder":2},{"sectionNumber":"5/2006","sectionType":"part","heading":"5/2006","content":"## 5/2006","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD stays within the original safety-focused purpose: it addresses a specific mechanical cause (high friction in the uplock roller bearing) linked to reported incidents and mandates a corrective modification. It does not appear to broaden the subject matter beyond that technical fix, add unrelated obligations, or expand coverage beyond the stated aircraft models and serial numbers."},"complexity_factors":["Short, single-subject AD (one required modification)","Single referenced service bulletin (Fokker SBF100-32-143) with allowance for later EASA-approved revision","One clear compliance timeframe (within 4,000 flight hours after effective date)","Applicability limited to two model-designations but covers all serial numbers","Minor cross-reference to another regulator's AD (CAA-NL AD NL-2006-004)","No defined-term heavy interpretation section, no nested exceptions or multiple compliance options"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- Requires owners/operators of Fokker F100 (F.28 Mk.0070 and Mk.0100) aeroplanes to modify the nose landing gear (NLG) door uplock bracket assembly.\n- The modification must follow the Accomplishment Instructions in Fokker Service Bulletin SBF100-32-143 dated 15 February 2006, or a later revision approved by EASA (European Union Aviation Safety Agency). (Requirement)\n- The work must be completed within 4,000 flight hours after 11 May 2006. This Airworthiness Directive (AD) became effective on 11 May 2006. (Compliance)\n\n**Who this affects**\n\n- All operators and owners of Fokker F100 aircraft of models F.28 Mk.0070 and Mk.0100 (all serial numbers). (Applicability)\n- Maintenance organisations and licensed engineers who carry out required modifications must follow the specified service bulletin and any regulator-approved revisions.\n\n**Why it matters (source claim and practical effect)**\n\n- The stated reason is that two incidents occurred where the Fokker 100 nose landing gear failed to extend normally and the nose gear doors were difficult to open in alternate (emergency) mode. Investigation identified high friction in the bearing of the roller in the uplock bracket assembly, which increased resistance in the door-unlocking mechanism. (Background)\n- By mandating the specified modification, the AD changes the hardware (or its operating characteristics) so the uplock roller friction is reduced or otherwise made reliable, lowering the risk of nose-gear-extension failures.\n\n**Who pays and who decides**\n\n- Aircraft operators pay for parts, labour, and aircraft downtime required to carry out the modification.\n- Work must be done to the methods in the Fokker service bulletin or an EASA‑approved revision; approval, airworthiness acceptance and continuation of operation are matters for the regulator(s) and approved maintenance organisations.\n\n**Practical trade-offs, implementation details and risks**\n\n- Direct costs: purchase of replacement parts or kits (if supplied), technician labour, and aircraft out-of-service time while modification is performed.\n- Scheduling costs: operators must plan the modification to fit within the 4,000 flight-hour window, which may require taking aircraft out of service at inconvenient times or incurring expedited supply/maintenance costs.\n- Supply and capability risks: availability of the specific parts or kits and availability of maintenance slots or approved shops may vary between operators and regions. Independent maintenance providers may perform the work if they follow the approved instructions and regulatory requirements.\n- Compliance verification: operators must keep records and present evidence of the modification when requested by the regulator; failure to comply risks grounding or enforcement action.\n\n**Regulatory and market effects to note**\n\n- The AD imposes a uniform mandatory change on all affected aircraft (concentrated obligation on the owners/operators of these models). Benefits (reduced risk of extension failure) accrue to those same operators and their passengers.\n- Costs are concentrated on the same operator group; there is no indication in the AD of subsidies, reimbursements or compensatory measures.\n- The AD references a Fokker service bulletin and allows later EASA-approved revisions; that permits the regulator to endorse iterative technical fixes while keeping the compliance requirement stable (reduces risk that operators must follow multiple divergent documents). (Requirement)\n- There is a cross-reference to a Netherlands CAA AD (CAA-NL AD NL-2006-004), showing coordination with the state of design/registry regulator. (Requirement note)\n\n**Summary statement**\n\nThis AD is a targeted safety requirement: it mandates a one-time hardware modification to the nose landing gear door uplock bracket assembly on all Fokker F100 aircraft of the two specified marks, to be done per the cited Fokker service bulletin (or an EASA-approved revision) within 4,000 flight hours of 11 May 2006. Operators bear the cost and must schedule approved maintenance to meet the deadline; the intended effect is to reduce the risk of nose-gear-extension failures arising from excessive uplock roller friction."},"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":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive with narrow, specific scope addressing a identified safety defect in particular aircraft models. The scope remains tightly focused on the original safety purpose."},"complexity_factors":["Very short document (approximately 200 words of substantive content)","Only 1 defined term implicitly referenced (NLG = Nose Landing Gear)","Single, unambiguous compliance requirement with clear reference to external technical document","No nested exceptions or conditional logic","Simple temporal compliance trigger (flight hours after effective date)","Straightforward applicability criteria (specific aircraft models, all serial numbers)"],"plain_english_summary":"This AD requires operators of Fokker F.28 Mk. 0070/0100 (Fokker 70/100) aircraft to modify the nose landing gear door uplock bracket assembly per Fokker Service Bulletin SBF100-32-143 (or later approved) because a high-friction bearing can prevent gear-door opening and inhibit gear extension.  \n\nCompliance is mandatory within 4,000 flight hours after 11 May 2006 to mitigate the risk of landing-gear failure and ensure safe landings."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f100-78-nlg-door-uplock-bracket-assembly","history":"/api/acts/ad-f100-78-nlg-door-uplock-bracket-assembly/history","analysis":"/api/acts/ad-f100-78-nlg-door-uplock-bracket-assembly/analysis","conflicts":"/api/acts/ad-f100-78-nlg-door-uplock-bracket-assembly/conflicts","importantCases":"/api/acts/ad-f100-78-nlg-door-uplock-bracket-assembly/important-cases","documents":"/api/acts/ad-f100-78-nlg-door-uplock-bracket-assembly/documents"}}