{"id":"F2022L01488","name":"AD/F100/98 — F100 Main Landing Gear Pistons overhauled by Aerospace NDI Pty Ltd","slug":"ad-f100-98-f100-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":102865,"registerId":"commonwealth-F2022L01488-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Fokker Services F100 (F28 Mk 100) Series","sectionType":"part","heading":"Fokker Services F100 (F28 Mk 100) Series Aeroplanes","content":"# Fokker Services F100 (F28 Mk 100) Series Aeroplanes\n\n| AD/F100/98 | F100 Main Landing Gear Pistons overhauled by Aerospace NDI Pty Ltd | 22/2022 |\n| ---------- | ------------------------------------------------------------------ | ------- |\n\n| Applicability: | F28 Mark 0100 aircraft equipped with any of Goodrich Main Landing Gear (MLG) part numbers (pn) 41050 -7/-8/-9/-10/-11/-12/-13/-14/-15/-16 or 41060 -3/-4/-5/-6 with pistons pn 41141-7 treated with any of:AeroNikl processserial number (sn) SS0057, SS0096, SS0140, SS0154, SS0167, SS0174, SS0185, SS0200, SS0210, SS0225, orAtotech processsn SS0028, SS0035, SS0045, SS0093, SS0112, SS0123, SS0130. SS0139, SS0151, SS0155, SS0157, SS0163, SS0164, SS0173, SS0176, SS0177, SS0182, SS0189, SS0190, SS0199, SS0214, SS0217, SS0223, SS0228, SS0230, SS0231, SS0236, SS0242, SS0265.or any other MLG that was overhauled at Aerospace NDI (ANDI) Pty Ltd as holder of CASA Certificate 1- RT6UE between 25 October 2019 to 18 November 2021 using either the AeroNikl or Atotech plating processes.                                                                                                                                                                                                                                                                                                                 |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | Carry out a Detailed Visual Inspection (DVI) of the pistons in accordance with Fokker Services All Operators Message (AOM) AOF100.230#5, as in force at the date of this AD.Note: The pistons are marked by serial number by an engraving near the torque link connection point.b. All pistons must be permanently removed from service and rendered unsalvageable.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |\n| Compliance:    | a. Prior to each flight, carry out a DVI as stated above.b. (i) Main landing gear part numbers that have had the pistons overhauled using the AeroNikl process must be removed from service by the effective date of this airworthiness directive.(ii) Main landing gear part numbers that have had the pistons overhauled using the Atotech process must be removed from service before1 February 2024.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |\n|                | This AD commences on 24 November 2022 (the effective date).                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n| Background:    | CASA received notification from the European Aviation Safety Agency (EASA) detailing that MLG pistons overhauled by ANDI were not compliant with the process contained in SAE/AMS2424. There have been missing detailed process sheets for the pistons and there is no proof that the test specimens are fully representative of the process applied to the pistons. This issue can cause internal hydrogen embrittlement and cause cracking after incorrect treatment. Hydrogen embrittlement may lead to a failure of the MLG axle piston resulting in dual wheel separation.The effected AeroNikl components were required to be removed from service in accordance with Fokker all operator message AOF100.230 #3 before 1 March 2022. The subject CASA AD supports the requirements stated within the Fokker all operator message.EASA has requested that the remainder Atotech effected components be removed from service before the 1 February 2024 to ensure that the airworthiness of the Australian F28 fleet is safeguarded, and that the affected units are not introduced into the worldwide supply chain. |\n\n![Signature of delegate](image.001.jpeg)\n\nDavid Punshon  \nDelegate of the Civil Aviation Safety Authority\n\n24 October 2022","sortOrder":0},{"sectionNumber":"AD/F100/98","sectionType":"part","heading":"AD/F100/98","content":"## AD/F100/98","sortOrder":1},{"sectionNumber":"F100 Main Landing Gear Pistons overhaule","sectionType":"part","heading":"F100 Main Landing Gear Pistons overhauled by Aerospace NDI Pty Ltd","content":"## F100 Main Landing Gear Pistons overhauled by Aerospace NDI Pty Ltd","sortOrder":2},{"sectionNumber":"22/2022","sectionType":"part","heading":"22/2022","content":"## 22/2022","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard Airworthiness Directive with focused, targeted applicability. It addresses a specific safety defect identified in a specific batch of overhauled components. The scope remains tightly constrained to the identified risk (hydrogen embrittlement in specific MLG pistons) and does not expand beyond the original safety purpose."},"complexity_factors":["Multiple overlapping applicability criteria (specific aircraft type, specific manufacturer part numbers, specific sub-component serial numbers, specific overhaul facility, specific date range, specific plating processes)","Nested conditional requirements with different deadlines for AeroNikl vs Atotech processes","Cross-reference to external technical document (Fokker Services AOM AOF100.230#5) without reproducing its contents","Technical aviation terminology requiring domain knowledge (hydrogen embrittlement, Detailed Visual Inspection, torque link connection point, SAE/AMS2424 standard)","Dual compliance pathway (immediate inspection + phased removal with different deadlines)","Reference to international regulatory coordination (EASA notification and alignment with European requirements)"],"plain_english_summary":"This AD orders operators of Fokker F100 aircraft to inspect before every flight and permanently remove from service certain Goodrich main landing gear pistons overhauled by Aerospace NDI Pty Ltd (Oct 2019–Nov 2021) using AeroNikl or Atotech coatings. The pistons may have hydrogen embrittlement, risking catastrophic dual-wheel loss.\n\nAeroNikl-treated pistons must be removed immediately; Atotech-treated pistons by 1 Feb 2024; removed pistons must be rendered unsalvageable."},"flash_summary":{"complexity_score":6,"scope_assessment":{"changed":false,"description":"The AD formalises and enforces actions already identified by Fokker All Operators Messages and EASA notifications: inspection and removal of MLG pistons overhauled at ANDI between 25 Oct 2019 and 18 Nov 2021 using AeroNikl or Atotech processes (Applicability, Requirement, Background). It does not broaden the universe of affected components beyond those listed, but it does set binding removal deadlines (immediate for AeroNikl-processed units and 1 Feb 2024 for Atotech-processed units) and mandates unsalvageable disposition (Compliance, Requirement)."},"complexity_factors":["Detailed applicability: multiple Goodrich MLG part numbers and a long list of piston serial numbers and two distinct plating processes (AeroNikl, Atotech) must be checked (Applicability).","Identification burden: pistons must be located by an engraved serial number near the torque link connection point (Requirement/Applicability).","Operational compliance frequency: a Detailed Visual Inspection (DVI) is required prior to each flight until removal, creating recurring operational checks (Compliance a).","Staggered removal deadlines: immediate removal by the AD effective date for AeroNikl-processed pistons, and a later deadline (1 Feb 2024) for Atotech-processed pistons, imposing differing scheduling and logistics (Compliance b(i)-(ii)).","Final disposition: removed pistons must be rendered unsalvageable, affecting parts inventory and spare-parts management (Requirement b).","Technical uncertainty and evidence gap: background notes missing process sheets and unrepresentative test specimens (Background), increasing inspection and engineering confirmation needs.","Cross-reference obligations: inspections and procedures must follow Fokker Services AOM AOF100.230#5 as in force on the AD date, requiring operators to track and apply external documents (Requirement).","Safety risk linkage: specified risk is hydrogen embrittlement potentially causing MLG axle piston failure and dual wheel separation, which drives the mandatory removals (Background).","Regulatory coordination: the AD enforces EASA/Fokker notifications and deadlines, so operators must reconcile multiple authorities' communications (Background)."],"plain_english_summary":"This airworthiness directive requires operators of Fokker F100 (F28 Mk 100) aeroplanes to inspect specified Goodrich main landing gear (MLG) pistons overhauled by Aerospace NDI (ANDI) and to permanently remove affected pistons from service. It applies to pistons identified by part/serial numbers and overhaul process (AeroNikl or Atotech) performed at ANDI between 25 Oct 2019 and 18 Nov 2021. The measure aims to prevent piston cracking from possible hydrogen embrittlement that could cause wheel separation."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f100-98-f100-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd","history":"/api/acts/ad-f100-98-f100-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd/history","analysis":"/api/acts/ad-f100-98-f100-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd/analysis","conflicts":"/api/acts/ad-f100-98-f100-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd/conflicts","importantCases":"/api/acts/ad-f100-98-f100-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd/important-cases","documents":"/api/acts/ad-f100-98-f100-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd/documents"}}