{"id":"F2022L01489","name":"AD/F28/93 — F70 Main Landing Gear Pistons overhauled by Aerospace NDI Pty Ltd","slug":"ad-f28-93-f70-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":102868,"registerId":"commonwealth-F2022L01489-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Fokker Services F28 Series Aeroplanes","sectionType":"part","heading":"Fokker Services F28 Series Aeroplanes","content":"# Fokker Services F28 Series Aeroplanes\n\n| AD/F28/93 | F70 Main Landing Gear Pistons overhauled by Aerospace NDI Pty Ltd | 22/2022 |\n| --------- | ----------------------------------------------------------------- | ------- |\n\n| Applicability: | F28 Mark 0070 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/F28/93","sectionType":"part","heading":"AD/F28/93","content":"## AD/F28/93","sortOrder":1},{"sectionNumber":"F70 Main Landing Gear Pistons overhauled","sectionType":"part","heading":"F70 Main Landing Gear Pistons overhauled by Aerospace NDI Pty Ltd","content":"## F70 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":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific safety defect in specific landing gear components from a specific maintenance provider during a defined time period. The two-tier removal timeline (immediate for AeroNikl, delayed for Atotech) reflects proportionate risk management rather than scope creep, aligning with the international coordination with EASA."},"complexity_factors":["Dense technical applicability section with multiple nested conditions (aircraft type × part numbers × process types × serial number ranges × date ranges × certificate holder)","Requires cross-referencing external documents: Fokker Services AOM AOF100.230#5, SAE/AMS2424 standard, EASA notifications, and CASA Certificate 1-RT6UE","Two-tier compliance structure with different deadlines for different plating processes (AeroNikl vs Atotech)","Specific technical terminology requiring aviation engineering knowledge (hydrogen embrittlement, DVI, torque link connection point, plating processes)","Serial number lists are extensive but not exhaustive (24 serial numbers listed, plus open-ended catch-all for 'any other' ANDI-overhauled gear)"],"plain_english_summary":"This AD orders operators of Fokker F28 Mark 0070 (F70) aircraft to inspect and remove specific main landing gear pistons overhauled by Aerospace NDI Pty Ltd using AeroNikl or Atotech plating. Inadequate overhaul records and possible SAE/AMS2424 non‑compliance raise hydrogen embrittlement risk.\n\nAffected pistons must be visually checked before flight and permanently removed/scrapped by the specified dates. It targets Australian operators and maintenance organisations to prevent landing‑gear failure and unsafe flights."},"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"},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":true,"description":"This AD converts Fokker AOM instructions into mandatory CASA requirements, sustains pre-flight inspection obligations until removal, and extends enforceable removal timing to Atotech-treated pistons (deadline 1 Feb 2024) while confirming immediate removal for AeroNikl-treated pistons by the AD effective date; it therefore broadens enforceability and clarifies disposal (Applicability; Requirement; Compliance; Background)."},"complexity_factors":["Long, specific applicability list of part numbers, serial numbers and two distinct plating-process sets (Applicability)","Two different removal deadlines depending on plating process (AeroNikl immediate by effective date; Atotech by 1 Feb 2024) creating staged compliance (Compliance b(i)-(ii))","Ongoing operational burden: required Detailed Visual Inspection prior to every flight until removal (Compliance a)","Definitive removal and unsalvageable requirement increases logistics and disposal cost for operators (Requirement b)","Need to identify plating process and match engraved piston serial numbers to listed process serials—traceability and record-checking burden (Applicability; Requirement note)","Dependence on manufacturer's All Operators Message AOF100.230#5 for inspection procedure, creating cross-document compliance reliance (Requirement)","Regulatory coordination: CASA action supports EASA notification and prior Fokker AOM actions, requiring operators to track multiple regulatory instruments and prior deadlines (Background)"],"plain_english_summary":"Requires operators of Fokker F28 Mark 0070 aeroplanes with specified Goodrich main landing gear pistons overhauled at Aerospace NDI (ANDI) between 25 Oct 2019 and 18 Nov 2021 to perform a detailed visual inspection (DVI) before each flight and to remove affected pistons from service by set deadlines; removed units must be rendered unsalvageable. CASA states this responds to non‑compliant AeroNikl/Atotech plating processes that risk hydrogen embrittlement, cracking and possible dual wheel separation (Applicability; Requirement; Background)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f28-93-f70-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd","history":"/api/acts/ad-f28-93-f70-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd/history","analysis":"/api/acts/ad-f28-93-f70-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd/analysis","conflicts":"/api/acts/ad-f28-93-f70-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd/conflicts","importantCases":"/api/acts/ad-f28-93-f70-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd/important-cases","documents":"/api/acts/ad-f28-93-f70-main-landing-gear-pistons-overhauled-by-aerospace-ndi-pty-ltd/documents"}}