{"id":"F2007L02661","name":"AD/ATR 42/18 - Pitot Probe Current Sensors","slug":"ad-atr-42-18-pitot-probe-current-sensors","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":68505,"registerId":"commonwealth-F2007L02661-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Avions de Transport Regional ATR 42 Seri","sectionType":"division","heading":"Avions de Transport Regional ATR 42 Series Aeroplanes","content":"### Avions de Transport Regional ATR 42 Series Aeroplanes\n\n| AD/ATR 42/18 | Pitot Probe Current Sensors | 10/2007 |\n| ------------ | --------------------------- | ------- |\n\n| Applicability: | All ATR 42 series aircraft models, all serial numbers, except aircraft modified per ATR modification 05469 (Installation of new current sensors for pitot probes) during production (ie MSN 631 and subsequent) or per ATR Service Bulletin (SB)ATR42-30-0072 at any approved revision whilst in service. |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Verify the three pitot probes’ heating resistance in accordance with the instructions of SB ATR42-30-0074 dated 14 May 2007 or later revision approved by the European Aviation Safety Agency (EASA).                                                                                                  |\n|                | 2. If, during the Requirement 1 verification, any resistance exceeding 50 Ohms is found, replace the pitot probe in accordance with the instructions of SBATR42-30-0074 or later revision approved by the EASA.                                                                                           |\n|                | 3. Replace the three pitot probe current sensors in accordance with the instructions of SB ATR42-30-0072 Revision 1 dated 1 June 2005 or later revision approved by the EASA.                                                                                                                             |\n|                | Replacement of the pitot probe current sensors is terminating action for the Requirement 1 repetitive verification tests.                                                                                                                                                                                 |\n|                | Note: EASA AD 2007-0179 refers.                                                                                                                                                                                                                                                                           |\n| Compliance:    | For Requirement 1 - Within the next 550 hours time in service (TIS) after the effective date of this Directive and thereafter at intervals not to exceed 550 hours TIS until the pitot probe current sensors are replaced in accordance with Requirement 3.                                               |\n|                | For Requirement 2 - Before next flight after the Requirement 1 verification test.                                                                                                                                                                                                                         |\n|                | For Requirement 3 - Within the next 5 000 hours TIS after the effective date of this Directive.                                                                                                                                                                                                           |\n|                | This Airworthiness Directive becomes effective on 27 September 2007.                                                                                                                                                                                                                                      |\n| Background:    | The EASA has received a report that a recent incident indicated that some failures of the pitot probe heating resistance may not be detected by the low current detection system on aircraft not equipped with modification 05469 (SB ATR42-30-0072).                                                     |\n\n|     | This Directive requires repetitive verification of the pitot probes’ resistance and replacement of any defective probes, together with ultimate replacement of the three low current sensors for Captain, First Officer and Standby pitot probes. |\n| --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n\n![](image.001.png)  \nCharles Lenarcic  \nDelegate of the Civil Aviation Safety Authority\n\n3 August 2007","sortOrder":0},{"sectionNumber":"AD/ATR 42/18","sectionType":"part","heading":"AD/ATR 42/18","content":"## AD/ATR 42/18","sortOrder":1},{"sectionNumber":"Pitot Probe Current Sensors","sectionType":"part","heading":"Pitot Probe Current Sensors","content":"## Pitot Probe Current Sensors","sortOrder":2},{"sectionNumber":"10/2007","sectionType":"part","heading":"10/2007","content":"## 10/2007","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive applies to all ATR 42 series aircraft except those already modified per ATR mod 05469 or SB ATR42‑30‑0072. It prescribes inspection and replacement actions and cites EASA service bulletins; there is no text indicating an expansion or narrowing of scope from the instrument as issued."},"complexity_factors":["Multiple, interlocking requirements: repetitive resistance checks, immediate replacement if >50 Ω, and eventual sensor replacement as terminating action (Requirements 1–3).","Different compliance timeframes: 550 hours TIS repeats until sensor replacement, immediate action before next flight if a probe fails, and 5,000 hours TIS for sensor replacement (Compliance).","Applicability carve‑out for aircraft modified per ATR mod 05469 or per SB ATR42‑30‑0072, requiring careful fleet tracking (Applicability).","Dependence on external documents and approvals: testing and replacement must follow specific SBs and later EASA‑approved revisions, creating procedural dependence on regulator and manufacturer documents (Requirement texts and note referring to EASA AD 2007‑0179).","Operational impacts: need for measurement equipment, qualified maintenance personnel, parts availability and scheduling of downtime (implied by inspection and replacement requirements).","Clear terminating action linkage: replacement of sensors ends the repetitive 550‑hour checks, creating a one‑time capital cost versus ongoing maintenance trade‑off (Requirement 3).","Enforcement timing: 'before next flight' immediate action creates tight operational constraints if failures are found (Requirement 2)."],"plain_english_summary":"This directive requires ATR 42 operators (except aircraft modified by ATR mod 05469 or SB ATR42‑30‑0072) to test the three pitot probes’ heating resistance every 550 hours, replace any probe measuring over 50 ohms before the next flight, and install new pitot probe current sensors for the three probes within 5,000 hours. It aims to make the low‑current detection system reliably detect heating failures. Operators bear inspection and replacement costs, schedule downtime, and must follow EASA‑approved service bulletin instructions."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a standard, targeted Airworthiness Directive addressing a specific safety-of-flight issue identified by the manufacturer and European regulator. It has not expanded beyond its original purpose of addressing undetected pitot probe heating failures."},"complexity_factors":["Short, single-purpose instrument focused on one technical issue (pitot probe sensors)","Only 3 substantive requirements with clear sequential logic (inspect → replace if faulty → ultimate replacement)","Limited cross-referencing: only references external EASA documents (AD 2007-0179, Service Bulletins) and one modification number","Straightforward applicability clause with single exception (modification 05469 or SB ATR42-30-0072)","Clear compliance deadlines using standard aviation metrics (hours Time In Service)","No nested definitions, interpretation sections, or conditional exceptions within the instrument itself"],"plain_english_summary":"This CASA Airworthiness Directive affects ATR 42 operators (except aircraft with factory mod 05469 or the specified service bulletin upgrade). It mandates checking the three pitot-probe heating elements every 550 flight hours, immediately replacing any probe whose heater shows resistance above 50 Ω, and replacing the probe-monitoring sensors within 5,000 flight hours.\n\nIt responds to EASA findings that some heating failures went undetected, risking ice-blocked pitots and false airspeed indications; the rule forces timely repairs and an eventual monitoring-system upgrade to restore safety."}},"importantCases":[],"_links":{"self":"/api/acts/ad-atr-42-18-pitot-probe-current-sensors","history":"/api/acts/ad-atr-42-18-pitot-probe-current-sensors/history","analysis":"/api/acts/ad-atr-42-18-pitot-probe-current-sensors/analysis","conflicts":"/api/acts/ad-atr-42-18-pitot-probe-current-sensors/conflicts","importantCases":"/api/acts/ad-atr-42-18-pitot-probe-current-sensors/important-cases","documents":"/api/acts/ad-atr-42-18-pitot-probe-current-sensors/documents"}}