{"id":"F2006B06011","name":"AD/PA-44/5 - Engine Priming System - Modification","slug":"ad-pa-44-5-engine-priming-system-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114409,"registerId":"commonwealth-F2006B06011-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-44/5 - Engine Priming System - Modification","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)  Piper PA-44 (Seminole) Series Aeroplanes\n\n \n\nAD/PA-44/5 Engine Priming System - Modification 8/79\n\nApplicability: Model PA-44-180 with S/Nos. 44-7995001 to 44-7995190. Document:  1. Piper SB No. 634; or\n\n2. FAA AD 79-12-11, Amendment 39-3490.\n\n \n\nCompliance: Within 25 hours time in service after 29 June 1979.\n\n \n\nBackground: The engine fuel primer system of this aircraft is subject to cracking of lines and breakage of fittings and poses a fire hazard.\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\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused specifically on the engine priming system defect in a limited production run of aircraft. It has not expanded beyond its original safety purpose."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined applicability criteria (model number and serial number range)","Simple binary compliance pathway (follow either of 2 referenced documents)","Single, unambiguous deadline (25 hours time in service after fixed date)","No nested conditions, exceptions, or cross-references to other legislation","Clear, single-issue scope (one specific mechanical modification)","No interpretative provisions or discretionary powers"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it as a \"recall notice\" for aircraft, but legally binding.\n\n**What it does:** It requires owners and operators of specific Piper PA-44-180 Seminole aeroplanes to **modify their engine priming system** to fix a dangerous design flaw.\n\n**Who it affects:** \n- **Aircraft owners/operators** of Piper PA-44-180 models with serial numbers 44-7995001 through 44-7995190 (approximately 190 aircraft)\n- **Maintenance organisations** responsible for keeping these planes airworthy\n\n**The safety problem:** The engine fuel primer system (the mechanism that helps start cold engines by injecting extra fuel) has lines that **crack and fittings that break**. This creates a **fire hazard** because leaking fuel near hot engine components can ignite.\n\n**What must be done:**\n- Follow either **Piper Service Bulletin No. 634** or **FAA Airworthiness Directive 79-12-11** (the US equivalent safety order)\n- Complete the modification **within 25 hours of flying time** after 29 June 1979\n\n**Why it matters:** This directive prevents potential in-flight or ground fires that could destroy aircraft and kill occupants. Compliance is mandatory — flying without completing this modification would violate civil aviation law and invalidate the aircraft's certificate of airworthiness."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text supplied sets out the AD’s scope (specific PA-44-180 serial numbers) and required action (modification within 25 hours TIS) without indicating any expansion or narrowing from an earlier or original intent. The instrument’s effect, as written here, is to require the modification for the listed serial-number range using the referenced technical documents. (Applicability; Compliance; Document)"},"complexity_factors":["Narrow applicability: applies only to Piper PA-44-180 with serial numbers 44-7995001 to 44-7995190. (Applicability)","Clear deadline: single short compliance window — within 25 hours time in service after 29 June 1979 — which simplifies compliance timing but raises scheduling pressure. (Compliance)","Reliance on external technical documents: the AD delegates technical instructions to Piper SB No. 634 or FAA AD 79-12-11, so legal text is short but operational detail is in the referenced material. (Document)","Safety-critical technical work: modification addresses fuel-primer line cracking and fitting breakage, which is a specific mechanical risk to be remedied. (Background)","No alternative procedures or discretionary relief set out in the text provided — compliance path is prescriptive. (Document; Compliance)"],"plain_english_summary":"What this instrument does\n\n- This airworthiness directive (AD) requires a modification to the engine fuel priming system on specified Piper PA-44-180 (Seminole) aeroplanes. (Applicability; Compliance)\n- The modification must be completed within 25 hours time in service after 29 June 1979. (Compliance)\n- The technical method for the modification is the one set out in either Piper Service Bulletin No. 634 or FAA AD 79-12-11 (Amendment 39-3490). (Document)\n\nWho it affects\n\n- Owners and operators of Piper PA-44-180 aircraft having serial numbers 44-7995001 through 44-7995190 are the parties obliged by this directive. (Applicability)\n\nWhy it matters (official claim and the mechanical test of that claim)\n\n- The AD’s stated reason is that the engine fuel primer system has experienced cracking of lines and breakage of fittings, which the document says poses a fire hazard. (Background)\n- Mechanically, the AD achieves the stated safety objective by mandating a specified modification to the priming system within a short compliance window and by referring to defined technical instructions (the Piper service bulletin or the FAA AD) for how to carry out the work. (Compliance; Document)\n\nWho pays, who decides, and what behaviour changes\n\n- Who pays: The owners/operators of the affected aircraft must arrange for and bear the costs of having the modification done, because the AD imposes the compliance obligation on those aircraft. (Applicability; Compliance)\n- Who decides the method: The AD requires compliance with one of the two referenced technical documents (Piper SB No. 634 or FAA AD 79-12-11), so the specific parts and procedures used will be set by those documents. (Document)\n- Behaviour change required: Operators must have the priming-system modification carried out within the time limit or otherwise account for the AD in their maintenance actions; this will change maintenance scheduling and resource allocation for the affected aircraft. (Compliance)\n\nCosts, incentives, trade-offs and implementation risks (source-grounded)\n\n- Compliance burden and timing: The 25-hour time-in-service deadline after 29 June 1979 creates a short window in which the work must be performed; that produces a need for immediate scheduling of maintenance and potential short-term aircraft downtime. (Compliance)\n- Specification of method: Because the AD points to an external Piper service bulletin or an FAA AD for the technical steps, the exact parts, labour and qualifications required are determined by those referenced documents. Operators must follow those instructions to be in compliance. (Document)\n- Safety benefit vs opportunity cost: The AD aims to reduce the risk of fuel-line cracking and fitting breakage (the stated fire hazard). Meeting that objective requires operators to allocate money, labour and aircraft time to the modification instead of other uses; the AD text itself records the safety rationale but does not set out costs or compensation. (Background; Compliance)\n- Implementation risk: If the referenced documents are unclear or require parts/work that are hard to source, that could delay compliance; the AD itself does not provide alternatives or waivers in the text supplied. (Document)\n\nConcentrated benefits and diffuse costs (source-grounded observation)\n\n- The immediate safety benefit accrues to the specific aircraft and their users (concentrated benefit for owners/operators). The expense and downtime of complying fall to those same owners/operators, who must arrange the modification within the prescribed timeframe. (Applicability; Compliance; Background)\n\nSummary in one sentence\n\n- This AD obliges owners/operators of specified Piper PA-44-180 serial numbers to carry out a prescribed modification to the engine priming system within 25 hours time in service after 29 June 1979, citing known cracking and fitting failures as the safety reason and directing operators to follow Piper SB No. 634 or FAA AD 79-12-11 for the technical work. (Applicability; Compliance; Document; Background)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-44-5-engine-priming-system-modification","history":"/api/acts/ad-pa-44-5-engine-priming-system-modification/history","analysis":"/api/acts/ad-pa-44-5-engine-priming-system-modification/analysis","conflicts":"/api/acts/ad-pa-44-5-engine-priming-system-modification/conflicts","importantCases":"/api/acts/ad-pa-44-5-engine-priming-system-modification/important-cases","documents":"/api/acts/ad-pa-44-5-engine-priming-system-modification/documents"}}