{"id":"F2006B11277","name":"AD/MiG 15/2 - Engine Lubricating Oil","slug":"ad-mig-15-2-engine-lubricating-oil","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":57081,"registerId":"commonwealth-F2006B11277-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/MiG 15/2 - Engine Lubricating Oil","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Mikoyan and Gurevich (MiG 15) Series Aeroplanes\n\n \n\nAD/MiG 15/2 Engine Lubricating Oil  10/93 DM\n\n \n\nApplicability: All Lis 2 and Lis-2SB engines fitted to SB Lim-2 (MIG 15UTI) aircraft.\n\n \n\nRequirement: Withdraw from service those engines which have been operated while using synthetic lubricating oil such as oil manufactured to MIL-L-23699. These engines may be returned to service only with the explicit and specific approval of the engine manufacturer or the Authority.\n\n \n\nCompliance: Before further flight after 14 August 1993.\n\n \n\nBackground:  Synthetic lubricating oil is reputed to have been used in some engines in contravention of manufacturers data.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive’s practical scope aligns with its stated purpose in the text: it targets Lis 2 and Lis‑2SB engines on SB Lim‑2 (MiG‑15UTI) aircraft that have been operated with specified synthetic lubricating oil, requires withdrawal before further flight after 14 August 1993, and conditions return to service on explicit manufacturer or Authority approval. The instrument does not indicate a broader or different scope than its expressed requirement. (Applicability; Requirement; Compliance; Background)"},"complexity_factors":["Very narrow technical scope (specific engine models and aircraft). (Applicability)","Single, discrete required action: withdrawal of affected engines before next flight after stated date. (Requirement; Compliance)","Verification burden: operators must determine past use of a specific oil specification (e.g. MIL‑L‑23699), which may require record checks or testing. (Background)","Discretionary approval required from engine manufacturer or Authority introduces uncertainty about required remedial work and documentation. (Requirement)","No procedural detail for inspections, testing or evidence standards is provided, increasing implementation variance across operators and approvers. (Requirement)"],"plain_english_summary":"What this directive does (mechanically)\n\n- Applies to: all Lis 2 and Lis-2SB engines installed in SB Lim-2 (MiG‑15UTI) aircraft. (Applicability)\n- Action required: operators must withdraw from service any of those engines that have been operated using synthetic lubricating oil (for example oil meeting specification MIL‑L‑23699). Those withdrawn engines may only be returned to service with the explicit, specific approval of either the engine manufacturer or the Civil Aviation Authority. (Requirement)\n- Timing: the withdrawal must be done before the next flight after 14 August 1993. (Compliance)\n\nStated reason\n\n- The directive records that synthetic lubricating oil is reputed to have been used in some engines contrary to the engine manufacturer’s data. (Background)\n\nWho is affected and who decides\n\n- Who is affected: owners/operators of SB Lim‑2 (MiG‑15UTI) aircraft that have Lis 2 or Lis‑2SB engines. (Applicability)\n- Who must act: those owners/operators must withdraw affected engines and not fly until approval is granted. (Requirement)\n- Who decides return-to-service: the engine manufacturer or the Authority must give explicit, specific approval before a withdrawn engine is returned to service. (Requirement)\n\nCosts, incentives and trade-offs (mechanical effects)\n\n- Direct costs and burdens on operators: identifying which engines were operated with the specified synthetic oil, removing those engines from service, arranging inspections/repairs if required, and securing the manufacturer’s or Authority’s written approval. (Requirement, Background)\n- Operational costs: grounded aircraft while engines are withdrawn and under inspection or awaiting approval; potential need to replace engines or perform maintenance if oil use caused damage. (Requirement)\n- Compliance risk and verification burden: the directive does not set an inspection protocol; operators must demonstrate to the manufacturer or Authority that an engine is safe to return — which creates administrative and evidentiary costs and introduces uncertainty about the time and expense required to obtain approval. (Requirement)\n- Discretionary authority: the power to approve return-to-service rests with the engine manufacturer or the Authority, giving them judgment over what remedial work, testing or documentation is sufficient. That discretion affects how quickly and cheaply operators can resume flying. (Requirement)\n\nEffects on private enterprise and market behaviour\n\n- Concentration of effect: the directive targets a narrow set of engines and aircraft, so the burden is concentrated on those specific owners/operators rather than the wider market. (Applicability)\n- Contract freedom and supplier role: operators must rely on the engine manufacturer (or seek Authority approval) to regain permission to operate affected engines. That increases the manufacturer’s practical influence over continuing airworthiness decisions for these engines. (Requirement)\n- Competition and prices: because the directive requires manufacturer or regulator approval for return-to-service, independent maintenance providers may be constrained in returning engines to service without manufacturer involvement; this could raise costs or delay service if the manufacturer’s approval is required. (Requirement)\n\nImplementation risks and opportunity costs\n\n- Verification difficulty: proving whether a specified synthetic oil (e.g. MIL‑L‑23699) was used in the past may be hard if records or samples are incomplete. This can lengthen downtime and raise administrative costs. (Background)\n- Potential substitution effects: operators may avoid certain oils in future or change maintenance practices to reduce the risk of forced withdrawal, which could affect supply choices and maintenance contracts. (Requirement, Background)\n\nNet mechanical effect (summary)\n\n- Operators of the listed engines must ground and withdraw any engines that have been run on the specified synthetic oil before the next flight after 14 August 1993 and cannot return those engines to service without explicit approval from the engine manufacturer or the Authority. The directive shifts verification and approval costs onto operators, while placing the final return-to-service decision with the manufacturer or regulator. (Applicability; Requirement; Compliance; Background)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific technical issue with specific engines. It has not expanded beyond its original purpose of grounding engines with potential synthetic oil contamination."},"complexity_factors":["Extremely short document (under 200 words)","Only 2 defined applicability criteria (engine types and aircraft model)","Single, unambiguous requirement with no sub-conditions or exceptions","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Clear compliance deadline with no alternative methods of compliance (AMOC) described in the text itself","No nested definitions or interpretive provisions"],"plain_english_summary":"This is an **Airworthiness Directive** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft engines.\n\n**What it does:**\n- **Targets:** Lis 2 and Lis-2SB engines fitted to SB Lim-2 aircraft (also known as MiG 15UTI — a Soviet-era trainer jet, some of which ended up in private or heritage aviation in Australia).\n- **The problem:** Some of these engines were apparently run on synthetic lubricating oil (specifically oil meeting military specification MIL-L-23699), which goes against what the engine manufacturer allows.\n- **The fix:** Any engine that has used this wrong oil must be **grounded immediately** (before flying again after 14 August 1993). It can only return to service if the engine maker or CASA explicitly approves it.\n\n**Why it matters:**\nUsing the wrong oil in a jet engine can cause catastrophic failure — seized bearings, overheating, or in-flight engine shutdown. This directive is a blunt safety instrument: stop flying these engines until someone qualified verifies they're safe."}},"importantCases":[],"_links":{"self":"/api/acts/ad-mig-15-2-engine-lubricating-oil","history":"/api/acts/ad-mig-15-2-engine-lubricating-oil/history","analysis":"/api/acts/ad-mig-15-2-engine-lubricating-oil/analysis","conflicts":"/api/acts/ad-mig-15-2-engine-lubricating-oil/conflicts","importantCases":"/api/acts/ad-mig-15-2-engine-lubricating-oil/important-cases","documents":"/api/acts/ad-mig-15-2-engine-lubricating-oil/documents"}}