{"id":"F2006B09088","name":"AD/DHC-3/38 - Electrically Heated Engine Pneumatic Lines","slug":"ad-dhc-3-38-electrically-heated-engine-pneumatic-lines","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115641,"registerId":"commonwealth-F2006B09088-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# ![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.\n\n![](image.001.png)\n\nDHC-3 (Otter) Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/DHC-3/38 Electrically Heated Engine P","sectionType":"part","heading":"AD/DHC-3/38 Electrically Heated Engine Pneumatic Lines 12/2002","content":"# AD/DHC-3/38 Electrically Heated Engine Pneumatic Lines 12/2002\n\nApplicability: DHC-3 “Turbo Otter” aircraft, all series, modified in accordance with A.M. Luton, United States Federal Aviation Administration (FAA) Supplemental Type Certificate (STC) No. SA3777NM or with Transport Canada Aviation equivalent Supplemental Type Approval No. SA89-32.\n\nRequirement: 1. Inspect the electrical wiring to the P3 and Py engine pneumatic line heating blankets and to the P3 heater warning light to determine if they are wired in a parallel configuration. Sheet 1 of Drawing No. 20075 “Electrical System Schematic” Rev. I dated 10 October 2000 (hereafter referred to as ‘The Drawing’) as referenced in A.M. Luton Service Information Letter SIL-00-10-10 dated 22 March 2001 (hereafter referred to as the ‘SIL’) illustrates the correct wiring configuration. If the inspection determines that lines are correctly wired in a parallel configuration, proceed to Requirement 3.\n\nNote 1: CASA recommends that the electrical inspection of the wiring include a continuity check of the heating blanket line(s) to ensure that they are serviceable. Then, after selecting the P3 heater switch to the “On” position, if the line(s) quickly feel warm to the touch, this is an additional indication that the line(s) are correctly configured.\n\n    2. If, as a result of the Requirement 2 inspection, it is determined that the P3 and Py engine pneumatic line heating blankets and the P3 heater warning light are incorrectly wired, modify the wiring to the configuration shown on The Drawing.\n\nNote 2: CASA recommends that a similar test be performed as described in Note 1 after modifying the wiring.\n\n    3. Inspect the circuit breaker switch for the heated engine pneumatic lines circuit ensuring the following:\n\n    If the engine installation utilizes both P3 and Py heated pneumatic lines, unless already accomplished, install a 7.5 Amp circuit breaker switch in accordance with The Drawing. Potter & Brumfield part number (P/N) W31- X2M1G-7.5, as referenced in the SIL, is an acceptable circuit breaker switch.\n    If the engine installation utilizes only a P3 heated pneumatic line, unless already accomplished, install a 5.0 Amp circuit breaker switch in accordance with The Drawing. Potter & Brumfield P/N W31-X2M1G-5.0 is an acceptable circuit breaker switch.","sortOrder":1}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard single-issue Airworthiness Directive focused on a specific unsafe wiring condition in a particular aircraft modification. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single specific aircraft type and modification (DHC-3 Turbo Otter with specific STC)","Three sequential requirements with clear conditional logic (if/then structure)","References to external technical documents (Drawing No. 20075 Rev. I, Service Information Letter SIL-00-10-10) without reproducing their full content","Two specific part numbers for circuit breakers with amperage variants based on configuration","Minimal defined terms (only 'The Drawing' and 'SIL' are explicitly defined)","No nested exceptions or complex cross-referencing to other legislation"],"plain_english_summary":"This CASA Airworthiness Directive applies to DHC‑3 “Turbo Otter” aircraft fitted with the A.M. Luton engine heating STC (US SA3777NM / Canadian SA89‑32). It mandates inspection and correction of the heated pneumatic‑line electrical wiring and installation of the appropriate circuit breaker to eliminate incorrect wiring configurations. The AD addresses a fire, overheating and system‑failure risk in cold‑weather operations caused by improper electrical installation."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD's scope is confined to DHC‑3 aircraft modified under the listed STCs and addresses wiring configuration and circuit‑breaker ratings only. The document does not expand requirements to other models or systems beyond the P3/Py heated pneumatic lines and P3 heater warning light; there is no indication in the text provided that the scope has changed from its stated purpose of correcting that unsafe condition."},"complexity_factors":["Applicability is narrow but specific: DHC‑3 ‘Turbo Otter’ aircraft modified per A.M. Luton STC No. SA3777NM or Transport Canada SA89‑32 (Applicability).","Technical reference dependency: inspection and any rewiring must conform to Drawing No. 20075 'Electrical System Schematic' Rev I and A.M. Luton Service Information Letter SIL‑00‑10‑10 (Requirement 1 and references).","Functional checks are recommended (continuity check and a warm‑to‑touch test after switching P3 heater on), adding procedural steps beyond a visual inspection (Note 1 and Note 2).","Corrective action requires electrical rework to a specified parallel configuration if miswired (Requirement 2).","Parts specification and decision logic: install a 7.5 A breaker when both P3 and Py heated lines are used or a 5.0 A breaker when only P3 is used; acceptable Potter & Brumfield part numbers are given (Requirement 3).","Compliance burden falls on aircraft owners/operators and maintenance providers: access to wiring, qualified personnel, procurement of specified parts, and aircraft downtime are required.","Regulatory basis: issued under subregulation 39.1(1) of CAR 1998, so it is mandatory for affected operators (header).","Small scope for implementer discretion: phrases like 'unless already accomplished' and unspecified compliance timing in the excerpt may require judgement by maintainers/regulator."],"plain_english_summary":"This Airworthiness Directive requires operators of DHC‑3 “Turbo Otter” aeroplanes modified under the specified STCs to inspect the electrical wiring for the P3 and Py heated pneumatic lines and the P3 heater warning light, rewire them if they are not in the parallel configuration shown on the referenced schematic, and install the correctly rated circuit breaker. It matters because incorrect wiring can prevent line heating or warning‑light operation; owners/operators pay for inspections, rewiring, parts and downtime, and maintenance staff must follow the referenced drawing and service information."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-3-38-electrically-heated-engine-pneumatic-lines","history":"/api/acts/ad-dhc-3-38-electrically-heated-engine-pneumatic-lines/history","analysis":"/api/acts/ad-dhc-3-38-electrically-heated-engine-pneumatic-lines/analysis","conflicts":"/api/acts/ad-dhc-3-38-electrically-heated-engine-pneumatic-lines/conflicts","importantCases":"/api/acts/ad-dhc-3-38-electrically-heated-engine-pneumatic-lines/important-cases","documents":"/api/acts/ad-dhc-3-38-electrically-heated-engine-pneumatic-lines/documents"}}