{"id":"F2006B02888","name":"AD/B737/187 - Captains Pitot Heater","slug":"ad-b737-187-captains-pitot-heater","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42230,"registerId":"commonwealth-F2006B02888-current","compilationNumber":null,"startDate":"2026-04-01","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\nBoeing 737 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/B737/187 Captain’s Pitot Heater 9/200","sectionType":"part","heading":"AD/B737/187 Captain’s Pitot Heater 9/2002","content":"# AD/B737/187 Captain’s Pitot Heater 9/2002\n\nApplicability: Model 737-600, \\-700, \\-800, and \\-900 series aeroplanes listed in Boeing Alert Service Bulletin (ASB) 737-24A1150, dated 11April 2002.\n\nRequirement: 1. Measure the electrical voltage at the circuit breaker for the aircraft captain's pitot heater to determine if the pitot heater is connected to the correct power supply bus, in accordance with ASB 737-24A1150. If the measurement is 100 to 122 volts alternating current (AC), no further action is required by this Directive.\n\n2. If the measurement is not 100 to 122 volts AC, perform all actions associated with connecting the subject circuit breaker wire to the 115-volt AC standby power supply bus (including performing a test to ensure that the pitot heater system operates correctly, repeating the measurement of the electrical voltage at the circuit breaker for the captain's pitot heater, and troubleshooting and correcting the wire connections until the test and measurement are successful), in accordance with ASB 737-24A1150.\n\nNote: FAA AD 2002-14-20 Amdt 39-12820 refers.\n\nCompliance: For Requirement 1 \\- Within 60 days after the effective date of this Directive.\n\nFor Requirement 2 \\- Before further flight after the Requirement 1 voltage measurement.\n\nThis Airworthiness Directive becomes effective on 5 September 2002.","sortOrder":1}],"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":3,"scope_assessment":{"changed":false,"description":"No change of scope is apparent within the text: the AD applies only to the Boeing 737 models listed in Boeing ASB 737-24A1150 and prescribes a measurement and corrective connection to the 115 V AC standby bus (Requirement 1 and 2). Who pays: aircraft operators and their maintenance providers bear inspection, potential rewiring and testing costs (Requirement; Compliance). Who decides: the CASA delegate issued the AD under subregulation 39.1(1) of CAR 1998. Behaviour change: operators must measure voltage within 60 days and complete any corrective actions and functional tests before further flight (Compliance)."},"complexity_factors":["Technical electrical check and verification of AC voltage at a specific circuit breaker","Potential need for wiring changes, troubleshooting and functional testing if voltage is outside tolerance","Procedural dependence on Boeing Alert Service Bulletin 737-24A1150 for detailed instructions","Targeted applicability to specified 737-600/700/800/900 aeroplanes listed in the ASB","Two-step compliance timing (initial measurement within 60 days; corrective action before further flight)","Regulatory cross-reference to FAA AD 2002-14-20"],"plain_english_summary":"This Airworthiness Directive requires operators of specified Boeing 737-600/700/800/900 aeroplanes to check the captain’s pitot heater circuit-breaker voltage and, if it is not 100–122 volts AC, move the heater feed to the 115‑volt AC standby power bus and verify operation. It affects aircraft operators and maintenance organisations, who must perform the inspection and any rewiring/testing within the stated time limits because the heater power source affects pitot system functionality and flightworthiness."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific wiring defect in specific aircraft models. It has not expanded beyond its original technical purpose."},"complexity_factors":["Single, specific technical requirement with clear binary outcome (voltage measurement either passes or fails)","Only 2 defined compliance paths based on measurement result","References external technical document (Boeing ASB) but incorporates it by clear description","No nested exceptions or conditional logic beyond the simple if/then structure","Short document (approximately 250 words) with straightforward temporal compliance requirements"],"plain_english_summary":"This Airworthiness Directive requires operators of certain Boeing 737-600/-700/-800/-900 series to verify the captain’s pitot tube heater is fed from the correct standby power. Within 60 days mechanics must check the circuit-breaker voltage and, if it’s outside the acceptable range, rewire to the proper standby supply and test before the next flight. It prevents heater failure and potential loss of airspeed indication."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-187-captains-pitot-heater","history":"/api/acts/ad-b737-187-captains-pitot-heater/history","analysis":"/api/acts/ad-b737-187-captains-pitot-heater/analysis","conflicts":"/api/acts/ad-b737-187-captains-pitot-heater/conflicts","importantCases":"/api/acts/ad-b737-187-captains-pitot-heater/important-cases","documents":"/api/acts/ad-b737-187-captains-pitot-heater/documents"}}