{"id":"F2005L00235","name":"AD/PA-23/90 - Turbo-Charger Oil Tank","slug":"ad-pa-23-90-turbo-charger-oil-tank","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":33798,"registerId":"commonwealth-F2005L00235-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Piper PA-23 (Apache and Aztec) Series Ae","sectionType":"division","heading":"Piper PA-23 (Apache and Aztec) Series Aeroplanes","content":"### Piper PA-23 (Apache and Aztec) Series Aeroplanes\n\n| AD/PA-23/90 | Turbo-Charger Oil Tank | 3/2005 |\n| ----------- | ---------------------- | ------ |\n\n| Applicability: | All The New Piper Aircraft, Inc. Models PA-23-235, PA-23-250, and PA-E23-250 aircraft equipped with AiResearch turbosupercharger systems:(a) configured in accordance with CASA AD/PA-23/56; or(b) configured in accordance with Supplementary Type Certificate (STC) SA852WE, SA909WE or SA978WE; or(c) installed in accordance with Piper Aircraft Corporation Drawing Number 32016.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Compliance with this directive is an alternate means of compliance withAD/PA-23/56.(a) Inspect the turbosupercharger system to ensure it complies with the requirements of AD/PA-23/56. If the turbosupercharger system complies with the requirements of AD/PA-23/56, no further action with regard to Paragraphs (b), (c), or (d) of this AD is required.(b) Inspect in accordance with the procedures in Garrett Aviation Service Bulletin No. 1002143, Revision A, dated June 18, 2004.(i) Replace any oil reservoir (P/N 286-P23-028-81 or 286-P23-028-111, or FAA-approved equivalent P/N) with a fireproof oil tank (P/N 10ND79200-1 or 10ND79200-3, or FAA-approved equivalent P/N); and(ii) Replace all installed oil reservoir hoses with fire-shielded hoses.(c) Inspect in accordance with the procedures in The New Piper Aircraft, Inc. Vendor Service Publication No. 166, dated August 20, 2004 and the procedures in Garrett Aviation Service Bulletin No. 1002143, Revision A, dated June 18, 2004, or subsequent FAA approved document.(i) Replace any oil reservoir (P/N 286-P23-028-81 or 286-P23-028-111, or FAA-approved equivalent P/N) with a fireproof oil tank (P/N 10ND79200-1 or 10ND79200-3, or FAA-approved equivalent P/N); and(ii) Replace all installed oil reservoir hoses with fire-shielded hoses. |\n\n|             | (d) Do not install any oil reservoir (P/N 286-P23-028 -81 or 286-P23-028-111, or FAA-approved equivalent P/N). Do not install any oil reservoir hose that is not fire-shielded.Note: FAA AD 2005-01-10 Amdt 39-13934 refers.                                                                                                                                                                                                                                                                                                                                                                                            |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance  | Unless already accomplished,(a) Within 100 hours time-in-service (TIS) or at the next annual inspection, after the effective date of this AD.(b) Within 100 hours TIS after the effective date of this AD.(c) Within 100 hours TIS after the effective date of this AD.(d) The effective date of this AD.                                                                                                                                                                                                                                                                                                               |\n|             | This Airworthiness Directive becomes effective on 17 March 2005.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |\n| Background: | In 1973 the then NAA issued AD/PA-23/56 as a result of a report of a fatal accident related to the breakdown of the turbocharger oil reservoir following a fire in the engine nacelle. This was followed by FAA AD 74-06-01, which has now been superseded by AD 2005-01-10. The actions specified in this AD are intended to prevent turbosupercharger oil reservoirs and associated hoses with inadequate fire resistance from failing when exposed to flame or exhaust gases. This failure could lead to an in-flight fire within the nacelle area penetrating the firewall and subsequent failure of the wing spar. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n4 February 2005","sortOrder":0},{"sectionNumber":"AD/PA-23/90","sectionType":"part","heading":"AD/PA-23/90","content":"## AD/PA-23/90","sortOrder":1},{"sectionNumber":"Turbo-Charger Oil Tank","sectionType":"part","heading":"Turbo-Charger Oil Tank","content":"## Turbo-Charger Oil Tank","sortOrder":2},{"sectionNumber":"3/2005","sectionType":"part","heading":"3/2005","content":"## 3/2005","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD does not broaden the original safety objective; it updates and specifies a concrete, alternate method of compliance to address the same hazard identified in the earlier AD/PA-23/56 (failure of turbosupercharger oil reservoirs and hoses under fire exposure). The directive remains targeted at the same aircraft models and turbosupercharger installations and narrows allowable parts to fireproof tanks and fire-shielded hoses. It therefore refines and enforces the original intent rather than expanding the legislative scope."},"complexity_factors":["Cross-references to multiple external documents (AD/PA-23/56, FAA AD 2005-01-10, Garrett SB No.1002143 Rev A, The New Piper Vendor Service Publication No.166)","Conditional logic: if the installation already complies with AD/PA-23/56, no further action; otherwise follow (b) or (c)","Multiple part numbers to track (old oil reservoir P/Ns 286-P23-028-81 and 286-P23-028-111; new fireproof tanks P/Ns 10ND79200-1 and 10ND79200-3) plus allowance for FAA-approved equivalents","Prohibition clause preventing future installation of specified old parts or non-fire-shielded hoses (Paragraph (d))","Two distinct inspection/repair procedures offered as alternate paths (Garrett SB alone or Piper vendor publication together with Garrett SB)","Clear, short compliance timeframes (100 hours TIS or next annual), reducing conditional complexity"],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- This Airworthiness Directive (AD) applies to New Piper PA-23 series aeroplanes (PA-23-235, PA-23-250 and PA-E23-250) when they are fitted with AiResearch turbosupercharger systems installed under certain prior approvals (CASA AD/PA-23/56, specific STCs, or a Piper drawing).  \n\n- It gives operators an alternate, updated way to comply with the older AD/PA-23/56. Mechanically, it requires inspections and, unless the installation already meets AD/PA-23/56, the replacement of certain oil reservoirs and hoses with fire-resistant parts. The specific actions are:  \n  - Check whether the turbosupercharger installation already complies with AD/PA-23/56; if it does, no further action under this AD is required (Requirement paragraph (a)).  \n  - If not, follow Garrett Aviation Service Bulletin No. 1002143 Rev A (Requirement paragraph (b)) or follow The New Piper Vendor Service Publication No. 166 together with the Garrett bulletin (Requirement paragraph (c)). Those procedures require:  \n    - Replacing any oil reservoir with part number (P/N) 286-P23-028-81 or 286-P23-028-111 (or FAA‑approved equivalent) with a fireproof oil tank, P/N 10ND79200-1 or 10ND79200-3 (or FAA‑approved equivalent); and  \n    - Replacing all installed oil reservoir hoses with fire‑shielded hoses.  \n  - The AD also prohibits installing the older oil reservoir P/Ns (286‑P23‑028‑81 or ‑111 or FAA‑equivalent) or any non-fire‑shielded oil reservoir hose on affected aircraft (Requirement paragraph (d)).\n\n- Compliance timing: Unless already done, the inspections/replacements must be accomplished within 100 hours time‑in‑service (TIS) or at the next annual inspection as stated for the relevant paragraphs. The AD is effective from the stated effective date.\n\n**Who is affected**\n\n- Owners and operators of the listed Piper PA-23 models that have the specified AiResearch turbosupercharger installations (including those installed under the listed STCs or Piper drawing).  \n- Maintenance organisations and certificated engineers who will perform the inspection and replacement work.  \n- Suppliers of the fireproof oil tanks and fire‑shielded hoses (they supply the parts required by the AD).\n\n**Why it matters (stated purpose and safety mechanism)**\n\n- The AD’s stated safety purpose is to prevent turbosupercharger oil reservoirs and hoses with inadequate fire resistance from failing when exposed to flame or hot exhaust gases. The failure mode of concern is an oil tank or hose breakdown in an engine-nacelle fire that could allow fire to penetrate the firewall and potentially cause structural failure (background section). The AD achieves this by removing older, less fire‑resistant parts and mandating parts with higher fire resistance.\n\n**Costs, incentives and operational effects (practical assessment)**\n\n- Who pays: Aircraft owners/operators pay for parts, labour and aircraft downtime required to carry out the inspections and replacements (Requirement paragraphs (b)–(c); Compliance section).  \n- Compliance burden: The AD prescribes specific service documents (Garrett SB and Piper vendor publication). The work requires qualified maintenance personnel and may need FAA‑approved part equivalents where applicable — this adds administrative steps for documentation and possible approval.  \n- Parts and supply risk: Compliance depends on availability of the fireproof tanks (P/Ns 10ND79200‑1/‑3 or FAA‑approved equivalents) and fire‑shielded hoses. Delays or limited supply increase downtime costs.  \n- Market effects: Maintenance shops and parts suppliers that can supply the approved tanks and hoses are likely to see increased demand. Operators who do not upgrade will be prohibited from fitting older parts, constraining their choice of cheaper or legacy parts.  \n- Behaviour change: Operators will either certify their installations as already compliant with AD/PA‑23/56 (and avoid replacements) or they must replace reservoirs and hoses and not reinstall legacy reservoirs or non-fire‑shielded hoses (Requirement paragraph (d)).  \n- Implementation risk and discretion: The AD references specific service bulletins and FAA‑approved equivalents. CASA’s delegate enforces the AD; individual maintenance organisations must interpret and apply the service-document procedures. Where FAA‑equivalent parts or documents are used, approval and record-keeping are required, which introduces some administrative discretion at the approval stage.  \n- Opportunity costs and trade-offs: Aircraft downtime and replacement costs are the direct trade-off against the increased fire-resistance safety objective. There is no compensatory funding in the AD; the operator bears the cost.\n\n**Relation to earlier instruments**\n\n- This AD is framed as an alternate means of compliance with the earlier AD/PA‑23/56 and references FAA AD 2005‑01‑10 (note). It updates the practical method for meeting the older AD by specifying new parts and service procedures.\n\n(References in this note: Requirement paragraphs (a)–(d); compliance timing; Garrett Aviation Service Bulletin No. 1002143 Rev A; The New Piper Vendor Service Publication No. 166; part numbers cited in the AD.)"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope focused specifically on turbocharger oil tank fire safety for the Piper PA-23 series. It does not expand beyond the original 1973 safety concern regarding fire penetration in engine nacelles. The directive serves as an alternate compliance path to an earlier AD rather than broadening the regulatory scope."},"complexity_factors":["Multiple compliance pathways (paragraphs a-d) with cross-references to prior directives (AD/PA-23/56) and external documents (Garrett Service Bulletin 1002143, Piper Vendor Service Publication 166)","Specific part number references (8 distinct part numbers plus 'FAA-approved equivalent' clauses)","Conditional logic: Paragraph (a) acts as an escape clause — if compliant with earlier AD, skip remaining requirements","Multiple applicability criteria (3 alternative configuration paths: CASA AD, STCs, or Piper drawing)","Nested document references requiring operators to consult external manufacturer service bulletins dated 2004","Reference to parallel FAA AD (2005-01-10) creating potential for confusion about which jurisdiction's rules apply"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's aviation regulator (CASA) that requires specific repairs or inspections on certain aircraft.\n\n**What it does:**\nThis directive orders owners and operators of specific Piper PA-23 Apache and Aztec aircraft to replace fire-prone turbocharger oil tanks and hoses with fire-resistant versions. The original oil reservoirs and unshielded hoses can fail when exposed to engine fires or exhaust heat, potentially causing catastrophic in-flight fires that could burn through the firewall and weaken the wing structure.\n\n**Who it affects:**\nOwners and operators of Piper PA-23-235, PA-23-250, and PA-E23-250 aircraft that have AiResearch turbocharger systems installed — specifically those configured under an earlier safety order (AD/PA-23/56) or certain approved modification certificates (STCs SA852WE, SA909WE, SA978WE) or Piper drawing 32016.\n\n**What must be done:**\n- **Inspect** the turbocharger system to confirm it meets the earlier safety standard (AD/PA-23/56). If it does, no further action needed.\n- **If not compliant:** Replace the oil reservoir (part numbers 286-P23-028-81 or 286-P23-028-111) with a fireproof tank (part numbers 10ND79200-1 or 10ND79200-3).\n- **Replace** all oil reservoir hoses with fire-shielded versions.\n- **Going forward:** Ban installation of the old, non-fireproof reservoirs and unshielded hoses.\n\n**When:**\nWithin 100 hours of flight time or at the next annual inspection after 17 March 2005 (the effective date).\n\n**Why it matters:**\nThis addresses a known fatal accident risk dating back to 1973. The original oil tanks can rupture in a fire, spraying flammable oil and allowing flames to penetrate the firewall — potentially causing wing spar failure and loss of the aircraft."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-23-90-turbo-charger-oil-tank","history":"/api/acts/ad-pa-23-90-turbo-charger-oil-tank/history","analysis":"/api/acts/ad-pa-23-90-turbo-charger-oil-tank/analysis","conflicts":"/api/acts/ad-pa-23-90-turbo-charger-oil-tank/conflicts","importantCases":"/api/acts/ad-pa-23-90-turbo-charger-oil-tank/important-cases","documents":"/api/acts/ad-pa-23-90-turbo-charger-oil-tank/documents"}}