{"id":"F2006B05716","name":"AD/PA-31/128 - Operation of Deicing Boots","slug":"ad-pa-31-128-operation-of-deicing-boots","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":135515,"registerId":"commonwealth-F2006B05716-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \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.","sortOrder":0},{"sectionNumber":"AD/PA-31/128 Operation of Deicing Boots ","sectionType":"part","heading":"AD/PA-31/128 Operation of Deicing Boots 7/2000","content":"# AD/PA-31/128 Operation of Deicing Boots 7/2000\n\nApplicability: Models PA31, PA-31-300, PA-31-325, PA-31-350, PA-31P, PA-31T, PA-31T1, PA-\n\n31T2, PA-31T3 and PA-31P-350 aircraft that are equipped with pneumatic deicing boots.\n\nRequirement: Revise the Limitations Section of the aircraft's Aircraft Flight Manual (AFM) by incorporating the following:\n\n\" Except for certain phases of flight where the AFM specifies that deicing boots should not be used (e.g., take-off, final approach, and landing), compliance with the following is required.\n\n    Wing and Tail Leading Edge Pneumatic Deicing Boot System, if installed, must be activated:\n\n    \\- At the first sign of ice formation anywhere on the aircraft, or upon annunciation from an ice detector system, whichever occurs first; and\n\n    \\- The system must either be continued to be operated in the automatic cycling mode, if available; or the system must be manually cycled as needed to minimize the ice accretions on the airframe.\n\n    The wing and tail leading edge pneumatic deicing boot system may be deactivated only after:\n\n    \\- leaving known or observed/detected icing that the flight crew has visually observed on the aircraft or was identified by the on-board sensors; and\n\n    \\- after the airplane is determined to be clear of ice.\"\n\nAlternatively, a copy of this Directive may be inserted in the Limitations Section of the Aircraft Flight Manual preceding the paragraph covering Operation in Icing Conditions.\n\nThis AFM amendment may be accomplished by the aircraft CoR holder, who can sign the aircraft logbook for completion of this Directive.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The AD requires explicit AFM Limitations text specifying mandatory activation and deactivation criteria for deicing boots and requires CoR holder logbook sign‑off; this imposes an explicit, documented AFM procedure for in‑flight boot operation where the AD supplies the required language (Requirement; Applicability)."},"complexity_factors":["Applicability lists multiple PA‑31 variants, so many individual aircraft/owners are affected (Applicability).","Requirement mandates a specific AFM Limitations text or insertion, creating a paperwork amendment task for Certificate‑of‑Registration holders (Requirement).","Operational language uses terms requiring pilot judgment — e.g. \"first sign of ice\", \"as needed\", and \"clear of ice\" — which allow variability in execution (Requirement).","Procedure allows either automatic cycling or manual cycling, producing procedural variability across fleets and crews (Requirement).","Logbook sign‑off by the aircraft CoR holder is required as evidence of compliance, concentrating administrative responsibility on owners/operators (Requirement).","Exemptions for certain flight phases (take‑off, final approach, landing) require cross‑checking existing AFM content and crew training (Requirement)."],"plain_english_summary":"This AD requires PA‑31 series aircraft with pneumatic deicing boots to have the AFM Limitations revised so boots are activated at the first sign of ice or on ice‑detector annunciation, and are cycled (automatic or manual) to minimise ice until the aeroplane is visually or sensor‑confirmed clear. AFM exceptions (e.g. take‑off, final approach, landing) remain.\n\nCertificate‑of‑Registration holders must amend the AFM and sign the logbook; flight crews must follow the AFM procedure (Requirement). This assigns who records compliance and prescribes in‑flight boot operation."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope: mandating a specific operational procedure for deicing boots on a defined set of Piper aircraft. It has not expanded beyond this safety-critical equipment modification."},"complexity_factors":["Very short document (approximately 300 words)","Only 11 specific aircraft models listed in applicability section","Single, straightforward requirement with clear alternative compliance method","No defined terms section — uses common aviation terminology only","No cross-references to other legislation or regulations beyond the enabling provision (subregulation 39.1(1) of CAR 1998)","Simple conditional logic: 'when to activate' and 'when to deactivate' with clear triggers","No exceptions, exemptions, or nested conditions"],"plain_english_summary":"This AD requires owners/operators of certain Piper PA‑31 series aircraft with pneumatic deicing boots to update their Aircraft Flight Manual with mandatory procedures for deicing-boot use: activate at the first sign of ice or on ice-detector alert, operate in automatic or manual cycling to prevent buildup, and deactivate only after visually confirming exit from icing and the aircraft is ice-free.\n\nThe Certificate of Registration holder may amend the AFM and sign off or insert a copy of this Directive."},"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-pa-31-128-operation-of-deicing-boots","history":"/api/acts/ad-pa-31-128-operation-of-deicing-boots/history","analysis":"/api/acts/ad-pa-31-128-operation-of-deicing-boots/analysis","conflicts":"/api/acts/ad-pa-31-128-operation-of-deicing-boots/conflicts","importantCases":"/api/acts/ad-pa-31-128-operation-of-deicing-boots/important-cases","documents":"/api/acts/ad-pa-31-128-operation-of-deicing-boots/documents"}}