{"id":"F2017L00562","name":"AD/A320/85 Amdt 1 - Probe Heat Computer","slug":"ad-a320-85-amdt-1-probe-heat-computer","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":96334,"registerId":"commonwealth-F2017L00562-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Airbus A319, A320 and A321 Series Aeropl","sectionType":"part","heading":"Airbus A319, A320 and A321 Series Aeroplanes","content":"# Airbus A319, A320 and A321 Series Aeroplanes\n\n| AD/A320/85 Amdt 1 | Probe Heat Computer | 11/2017 |\n| ----------------- | ------------------- | ------- |\n\n| Applicability: | All Airbus A319, A320 and A321 models not having Airbus modification No. 26403 or Airbus Service Bulletin (SB) A320-30-1036 as in force from time to time incorporated.                                                                                                                                                                                                                       |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | Unless previously incorporated, modify the wiring between engine interface units one and two with probe heat computer one and three in accordance with Airbus SB A320‑30-1036 as in force from time to time.Note 1: This AD is based on DGAC AD 97-203-102(B)R1.Note 2: The words “as in force from time to time” require compliance with the most recent version of the referenced document. |\n| Compliance:    | Prior to 22 May 1998.Note 3: Previous compliance with any requirement in AD/A320/85 constitutes compliance with the same requirement in this AD.                                                                                                                                                                                                                                              |\n|                | This AD commences on 26 May 2017.                                                                                                                                                                                                                                                                                                                                                             |\n| Background:    | This AD is intended to prevent a simultaneous loss of heating of probes (CAPT and STBY side) due to a single failure, which will induce erroneous anemometric calculations by the concerned systems whilst operating in freezing conditions.Amendment 1 is issued to clarify the AD applicability and update the DGAC AD reference to the latest revision.                                    |\n\n![](image.001.jpeg)\n\nPieter van Dijk  \nDelegate of the Civil Aviation Safety Authority\n\n18 May 2017","sortOrder":0},{"sectionNumber":"AD/A320/85 Amdt 1","sectionType":"part","heading":"AD/A320/85 Amdt 1","content":"## AD/A320/85 Amdt 1","sortOrder":1},{"sectionNumber":"Probe Heat Computer","sectionType":"part","heading":"Probe Heat Computer","content":"## Probe Heat Computer","sortOrder":2},{"sectionNumber":"11/2017","sectionType":"part","heading":"11/2017","content":"## 11/2017","sortOrder":3}],"analysis":{"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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"Amendment 1 clarifies which aeroplanes are affected and updates the referenced DGAC AD to the latest revision, but does not expand the set of required modifications. The instrument maintains the original technical requirement to modify probe heat computer wiring; the amendment updates applicability wording and external reference only (Background)."},"complexity_factors":["Applicability depends on whether aircraft have previously incorporated Airbus modification No. 26403 or SB A320‑30‑1036, creating a conditional universe of affected aircraft (Applicability).","Mandatory technical action: wiring modification between specific engine interface units and probe heat computers — requires technical labour, parts and aircraft downtime (Requirement).","Reference to external documents “as in force from time to time” imposes an ongoing duty to comply with the latest version of the referenced service bulletin, increasing procedural tracking and potential variation in required work (Requirement / Note 2).","Cross-reference to DGAC AD and statement that Amendment 1 clarifies applicability and updates that reference adds an international/regulatory-document tracking element (Background).","Confusing chronology: the AD states compliance must have been achieved prior to 22 May 1998 while the AD commencement date is 26 May 2017; this creates potential interpretive and record‑checking burdens for operators and regulators (Compliance).","Compliance credit for prior equivalent actions reduces administrative burden for some operators but requires proof of prior compliance (Compliance / Note 3).","Safety-critical nature of probe heating means strict operational impact if modifications are deferred or incorrectly performed; technical conformity must match the referenced SB precisely (Background / Requirement)."],"plain_english_summary":"Requires a wiring modification between engine interface units 1 and 2 and probe heat computers 1 and 3 on Airbus A319/A320/A321 aeroplanes that have not incorporated Airbus mod No. 26403 or SB A320‑30‑1036. It is intended to prevent a single failure from causing simultaneous loss of probe heating (captain and standby) which can produce erroneous airspeed/air-data calculations in freezing conditions; operators must incorporate the latest referenced service bulletin by the compliance date."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This amendment maintains the original scope of the 1998 directive. Amendment 1 makes no substantive changes to the safety requirement — it only clarifies applicability language and updates documentary references. The core mandate (rewiring probe heat computers) remains identical to the original AD/A320/85."},"complexity_factors":["Single technical requirement with clear applicability criteria","Only 2 defined technical references (Airbus modification No. 26403 and Service Bulletin A320-30-1036)","Simple conditional logic: applies to all aircraft EXCEPT those with specific prior modifications","No nested exceptions or multi-layered compliance pathways","Cross-references only to one external document (Airbus SB) and one foreign aviation directive (DGAC AD 97-203-102(B)R1)","Short, focused scope addressing one specific wiring modification"],"plain_english_summary":"This CASA Airworthiness Directive mandates rewiring the probe heat computer connections to the engine interface units on Airbus A319/A320/A321s to prevent a single electrical fault from disabling multiple probe heaters and risking pitot/probe icing and erroneous airspeed data. It applies to all operators unless aircraft have factory Mod 26403 or have complied with Service Bulletin A320‑30‑1036; a 2017 amendment clarifies affected aircraft and references the French AD."}},"importantCases":[],"_links":{"self":"/api/acts/ad-a320-85-amdt-1-probe-heat-computer","history":"/api/acts/ad-a320-85-amdt-1-probe-heat-computer/history","analysis":"/api/acts/ad-a320-85-amdt-1-probe-heat-computer/analysis","conflicts":"/api/acts/ad-a320-85-amdt-1-probe-heat-computer/conflicts","importantCases":"/api/acts/ad-a320-85-amdt-1-probe-heat-computer/important-cases","documents":"/api/acts/ad-a320-85-amdt-1-probe-heat-computer/documents"}}