{"id":"F2006B05953","name":"AD/PA-38/15 - Fuel Gauges and Engine Instrument Power Circuits - Modification","slug":"ad-pa-38-15-fuel-gauges-and-engine-instrument-power-circuits-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":136109,"registerId":"commonwealth-F2006B05953-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-38/15 - Fuel Gauges and Engine Instrument Power Circuits - 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-38 (Tomahawk) Series Aeroplanes\n\n \n\nAD/PA-38/15 Fuel Gauges and Engine Instrument\n\nPower Circuits - Modification\n\n\n11/79\n\n \n\nApplicability: All model PA-38-112 with S/Nos. 38-78A0002 to 38-78A0027, 38-78A0029 to 38- 78A0037, 38-78A0039 to 38-78A0041, 38-78A0043, 38-78A0045 to 38-78A0064,\n\n38-78A0066 to 38-78A0072 and 38-78A0074 to 38-78A0104.\n\n \n\nDocument: 1. Piper SB No. 603; or\n\n \n\n2. FAA AD 79-17-05.\n\n \n\nCompliance: Within 100 hours time in service after 30 November 1979.\n\n \n\nBackground: Fuel gauges and engine instruments have a common grounding point which under operating conditions has been shown to be unreliable. The modification installs a ground wire which will ensure normal operation.\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 AD remains tightly focused on its original purpose: correcting a specific electrical grounding defect in early production Piper PA-38 aircraft. The scope has not expanded beyond the identified safety issue and affected serial numbers."},"complexity_factors":["Very short document (approximately 200 words)","Only 4 defined elements: applicability (serial number ranges), two reference documents, and compliance deadline","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Single, straightforward mechanical modification with no conditional logic or exceptions","No nested provisions or alternative compliance paths","Background explanation provided in plain language"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it like a compulsory recall notice, but for aircraft rather than cars.\n\n**What it does:** It requires owners and operators of specific Piper PA-38 Tomahawk aeroplanes to modify their fuel gauges and engine instrument power circuits. The problem is that these instruments share a common grounding point (an electrical connection to the aircraft's frame) that can fail during flight. When this happens, pilots lose accurate fuel readings and engine data — obviously dangerous when you're airborne.\n\n**The fix:** Install a separate ground wire to ensure the instruments keep working properly.\n\n**Who must comply:** Owners of specific Piper PA-38-112 aircraft with serial numbers listed in the directive (roughly the first 100 or so aircraft manufactured in 1978). If your plane's serial number isn't on this list, this AD doesn't apply to you.\n\n**When:** The modification had to be completed within 100 hours of flying time after 30 November 1979.\n\n**Why it matters:** Faulty fuel gauges can lead to fuel starvation (running out of fuel unexpectedly), and failed engine instruments can prevent pilots from detecting engine problems early. Both scenarios create serious flight safety risks."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive implements a single corrective action described in the Background — installation of a ground wire to address an unreliable common ground for fuel gauges and engine instruments — for a defined set of PA-38-112 serial numbers. The AD confines requirements to those serial numbers and references the specific service documents to be followed, so it does not expand beyond that stated corrective scope (Applicability; Background; Document; Compliance)."},"complexity_factors":["Narrow, specific applicability limited to particular PA-38-112 serial numbers (Applicability).","Mandatory compliance with a single, simple modification (install ground wire) rather than an open-ended programme (Background).","Fixed and short compliance timeframe (within 100 hours TIS after 30 Nov 1979) which creates scheduling pressure (Compliance).","Reliance on external technical documents (Piper SB No. 603 or FAA AD 79-17-05) for the detailed installation steps, creating a procedural dependency (Document).","Operational impacts limited to parts/labour and downtime rather than regulatory reporting or ongoing obligations (Compliance; Background)."],"plain_english_summary":"This AD mandates installing a dedicated ground wire for fuel gauges and engine instruments on specified Piper PA‑38‑112 serial numbers to correct unreliable common grounding. Compliance—using Piper Service Bulletin No. 603 or FAA AD 79‑17‑05—is required within 100 hours TIS after 30 November 1979. Affected owners/operators must arrange and pay for the modification per the referenced procedures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-38-15-fuel-gauges-and-engine-instrument-power-circuits-modification","history":"/api/acts/ad-pa-38-15-fuel-gauges-and-engine-instrument-power-circuits-modification/history","analysis":"/api/acts/ad-pa-38-15-fuel-gauges-and-engine-instrument-power-circuits-modification/analysis","conflicts":"/api/acts/ad-pa-38-15-fuel-gauges-and-engine-instrument-power-circuits-modification/conflicts","importantCases":"/api/acts/ad-pa-38-15-fuel-gauges-and-engine-instrument-power-circuits-modification/important-cases","documents":"/api/acts/ad-pa-38-15-fuel-gauges-and-engine-instrument-power-circuits-modification/documents"}}