{"id":"F2008L04487","name":"AD/INST/57 - Harco Labs, Inc. Pitot/Angle of Attack Probes","slug":"ad-inst-57-harco-labs-inc-pitot-angle-of-attack-probes","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":76515,"registerId":"commonwealth-F2008L04487-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Instruments and Automatic Pilots","sectionType":"division","heading":"Instruments and Automatic Pilots","content":"### Instruments and Automatic Pilots\n\n| AD/INST/57 | Harco Labs, Inc. Pitot/Angle of Attack Probes | 13/2008 |\n| ---------- | --------------------------------------------- | ------- |\n\n| Applicability: | Harco Labs, Inc. pitot/angle of attack (AOA) probe part numbers (P/N) 100435-39, 100435-39-001, 100435-40 and 100435-40-001, serial numbers 740000 through 799999. |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| | Note 1: Pitot/AOA probes are known to be installed on, but not limited, to Eclipse Aviation Company Model EA500 aeroplanes, as follows: |\n| | a. Aeroplanes with a serial number in the range of 000001 through 000189, where the affected probe was installed at manufacture, or |\n| | b. Any serial number aeroplane where an affected probe was installed in the field. |\n| Requirement: | 1. Carry out a logbook check of the maintenance records to determine if any pitot/AOA probe (P/N 100435-39, 100435-39-001, 100435-40 or100435-40-001) with any affected serial number is installed. If, as a result of this check, it is positively identified that all P/N 100435-39, 100435-39-001,100435-40 or 100435-40-001 pitot/AOA probes installed do not have a serial number affected by this Directive, then no further action is required. |\n| | The owner/operator holding at least a private pilot licence may carry out the logbook check and make an entry into the aircraft logbook showing compliance with this Requirement. |\n| | 2. If, as a result of the Requirement 1 check, any pitot/AOA probe with an affected serial number is found to be installed or the serial number of any installed pitot/AOA probe cannot be positively identified, incorporate the following text into the Limitations Section of the aircraft flight manual (AFM): |\n| | a. “Operate Only under Day Visual Flight Rules (VFR)”; and |\n| | b. “File Only a VFR Flight Plan.” |\n| | Inserting a copy of this Directive into the AFM satisfies this Requirement. |\n| | The owner/operator holding at least a private pilot licence may insert the above information into the AFM and make an entry into the aircraft logbook showing compliance with this Requirement. |\n\n| | 3. If any pitot/AOA probe with an affected serial number is installed or the serial number of any installed pitot/AOA probe cannot be positively identified, test the pitot/AOA probe heater performance as follows: |\n| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | a. For all probes installed on Eclipse Model EA500 aeroplanes, use Eclipse Aviation Alert Service Bulletin SB 500-34-019, Rev C, dated20 August 2008, and |\n| | b. For all probes, use Harco Labs, Inc. Service Bulletin SB-34-10-10-001, Revision F, dated 19 August 2008, and Harco Pitot AOA Probe Internal Tubing Heater Verification Test Procedure P1149, Rev: E, also referenced in Appendix A of SB-34-10-10-001 Revision F. |\n| | Completion of the test with all pitot/AOA probes passing terminates the Requirement 2 AFM operational limitations. |\n| | 4. If any pitot/AOA probe fails the Requirement 3 test procedure, replace it with a pitot/AOA probe under the following situations: |\n| | a. The replacement pitot/AOA probe serial number is not affected by this Directive; |\n| | b. The replacement pitot/AOA probe successfully passes the Requirement 3 test procedure; or |\n| | c. The replacement pitot/AOA probe fails the test or is not tested and: |\n| | (i) the Requirement 3 test of the pitot/AOA probe is accomplish, and |\n| | (ii) a pitot/AOA probe that meets the criteria of Requirement 4.a. or 4.b. is installed within the next 90 days after 30 December 2008. |\n| | Any pitot/AOA probe replacement is to be accomplished following Eclipse Aviation Alert Service Bulletin SB 500-34-019, Rev C, dated 20 August 2008, or by following an approved repair procedure (eg the approved aircraft maintenance manual), as applicable. |\n| | 5. Any pitot/AOA probe with P/N 100435-39, 100435-39-001, 100435-40 or 100435-40-001 may not be installed on any aeroplane unless the criteria of Requirement 4.a., 4.b. or 4.c. are met. |\n| | 6. Remove the Requirement 2 operating limitations from the Limitations Section of the AFM. |\n| | Note 2: FAA AD 2008-19-01 Amdt 39-15668 refers. |\n| Compliance: | For Requirement 1 and 2 - Before further flight after 30 December 2008. |\n| | For Requirement 3 and 4 - Within the next 90 days after 30 December 2008. |\n| | For Requirement 5 - As of 18 December 2008 (the effective date of this Directive). |\n| | For Requirement 6 - Before further flight after completion of the Requirement 3 test with all pitot/AOA probes passing or replacement of all failed pitot/AOA probes with: |\n| | a. pitot/AOA probes having serial numbers not affected by this Directive, or |\n| | b. pitot/AOA probes successfully passing the test in accordance with Requirement 3. |\n| | This Airworthiness Directive becomes effective on 18 December 2008. |\n| Background: | The United States Federal Aviation Administration has received several reports of airspeed disagree caution indication due to blockage within the pitot/AOA system from freezing condensation. The Directive is issued to detect and correct improperly performing pitot/AOA probe heaters.This condition, if not corrected, could result in a blockage within the pitot/AOA system from condensation freezing with consequent incorrect indication of impact air pressure (airspeed/AOA). This blockage could lead to the stall warning becoming unreliable and the stick pusher, overspeed warning, autopilot, and yaw damper to malfunction.The requires the incorporation of information into the Limitations Section of the AFM that will allow operation only under day visual flight rules (VFR) and allow only a VFR flight plan. The Directive also requires the test the pitot/AOA probes for heater performance and replacement of the pitot/AOA probe if it fails the heater performance test. |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n6 November 2008","sortOrder":0},{"sectionNumber":"AD/INST/57","sectionType":"part","heading":"AD/INST/57","content":"## AD/INST/57","sortOrder":1},{"sectionNumber":"Harco Labs, Inc. Pitot/Angle of Attack P","sectionType":"part","heading":"Harco Labs, Inc. Pitot/Angle of Attack Probes","content":"## Harco Labs, Inc. Pitot/Angle of Attack Probes","sortOrder":2},{"sectionNumber":"13/2008","sectionType":"part","heading":"13/2008","content":"## 13/2008","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard single-issue Airworthiness Directive addressing a specific safety defect in particular aircraft components. The scope remains tightly focused on the identified pitot/AOA probe heater malfunction and does not extend beyond the original safety purpose."},"complexity_factors":["Multiple conditional pathways: Requirements 1–6 create a decision tree with nested conditions (e.g., Requirement 4 has three sub-options with one containing nested sub-clauses 4.c.(i) and 4.c.(ii))","Cross-references to external technical documents: Eclipse Aviation Alert Service Bulletin SB 500-34-019 Rev C and Harco Labs Service Bulletin SB-34-10-10-001 Revision F with Appendix A and Test Procedure P1149 Rev E","Dual compliance timelines: Immediate action required before further flight (Requirements 1–2) versus 90-day window (Requirements 3–4), plus absolute prohibition date (Requirement 5)","Serial number range specificity: Precise applicability criteria (serial numbers 740000–799999) requiring logbook verification","Permissive owner/operator provisions: Specific licensing requirements (private pilot licence minimum) allowing non-mechanics to perform certain tasks (logbook checks and AFM insertions)","Termination conditions: Requirement 6 removal of limitations contingent on multiple possible completion pathways (passing tests or replacement with qualifying probes)"],"plain_english_summary":"This CASA Airworthiness Directive orders owners/operators to inspect for specific Harco Labs pitot and angle-of-attack probes (certain part and serial numbers) that may have failed heaters allowing ice blockages. It primarily affects Eclipse EA500s but applies to any aircraft with those probes. If affected probes are present or unconfirmed, aircraft must be restricted to daytime VFR immediately; probes must be heater-tested within 90 days and replaced if they fail. Installation of those probe part numbers is prohibited after 18 Dec 2008 unless compliant."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD is narrowly targeted to detect and correct defective pitot/AOA probe heaters for specific Harco part numbers and serial ranges. The measures (record check, AFM operational limitations, heater testing, replacement, and prohibition on installing non-compliant probes) align with the stated safety objective of preventing freeze-related pitot/AOA blockages. It does not expand the subject matter beyond addressing that specific failure mode and the affected probes, so it has not grown beyond its original purpose."},"complexity_factors":["Clearly delimited applicability: 4 specific part numbers and a serial number range (740000–799999).","Six numbered Requirements with conditional branches (e.g. Requirement 2 triggered only if an affected or unidentified serial is found).","Cross-references to external documents: Eclipse SB 500-34-019 Rev C; Harco SB-34-10-10-001 Rev F; Harco Procedure P1149 Rev E (Requirement 3).","Multiple compliance timeframes: immediate (before further flight), 90-day window, effective date constraints (Compliance section).","Allowances for owner/operator administrative action (logbook and AFM entry) versus maintenance actions (testing/replacement) — mixed delegation of responsibilities (Requirements 1–2).","Replacement conditionality with a short-term remedial window (Requirement 4.c introduces a 90-day substitution exception).","Reference to FAA AD for related context (Note 2), increasing cross-jurisdictional tracing if needed.","Technical testing standard that must be followed (specific test procedure referenced), requiring specialised capability."],"plain_english_summary":"**What this instrument does (in simple terms)**\n\n- This Airworthiness Directive (AD) applies to certain Harco Labs pitot/angle-of-attack (AOA) probes (part numbers 100435-39, 100435-39-001, 100435-40 and 100435-40-001) with serial numbers 740000 through 799999. These probes are known to be installed on some Eclipse EA500 aeroplanes but could be on other types if those part/serial combinations were fitted (Applicability).\n\n- The AD requires operators to check records to see whether any affected probes are installed (Requirement 1). If an affected probe is present or the serial number cannot be positively identified, the operator must add two operational limitations to the aircraft flight manual (AFM): operate only in daytime Visual Flight Rules (VFR) and file only a VFR flight plan (Requirement 2).\n\n- If an affected or unidentified probe is present, the heater in the probe must be tested to a specific procedure (Requirement 3). Passing the heater test removes the AFM VFR limitations (Requirement 6). If a probe fails the heater test it must be replaced, or a compliant probe fitted within 90 days under limited conditions (Requirement 4). After the AD takes effect, the listed probe part numbers may not be installed unless they meet the replacement/test criteria (Requirement 5).\n\n**Who this affects**\n\n- Aircraft owners/operators and maintenance organisations that own, operate or maintain aeroplanes fitted with the listed Harco pitot/AOA probe part numbers and affected serial numbers.\n- Pilots/flight operations where the AFM is amended to VFR-only: this restriction affects when and how those aircraft can be flown until probes pass the required tests or are replaced.\n\n**Why it matters (safety and operational mechanics)**\n\n- The AD responds to reports that condensation can freeze inside the probe internal tubing and that some probe heaters do not perform correctly. A blocked pitot/AOA system can give incorrect airspeed or AOA readings, which can in turn make stall warning, stick pusher, overspeed warnings, autopilot and yaw damper unreliable (Background).\n\n- The AD’s mechanical effect is to identify suspect probes (record check), limit operations to reduce exposure to icing/IMC risk (AFM VFR-only limitation), require a standard heater-performance test (specific service bulletins and test procedure are referenced in Requirement 3), and require replacement where tests fail (Requirements 3–5). The AFM limitation is removed only after all installed probes pass the heater test or are replaced with probes that meet the AD criteria (Requirement 6).\n\n**Who pays and who decides**\n\n- Owners/operators pay for the record checks, AFM amendment entries, heater-performance testing, and any required probe replacements. Maintenance organisations or appropriately qualified personnel carry out the tests and replacements following the referenced service bulletins and approved procedures (Requirements 1–4 and compliance timeline).\n\n- The operator/owner decides whether a probe serial number is positively identified and may perform and log the record check and AFM insertion if they hold at least a private pilot licence (Requirements 1 and 2). Licensed maintenance personnel perform the heater verification test and any replacements (Requirement 3 and 4).\n\n**Practical costs, incentives and trade-offs**\n\n- Direct costs: time and labour for logbook checks, AFM amendments, heater-performance tests, potential replacement costs for failed probes, and aircraft downtime while testing or waiting for replacement probes. The AD sets a 90-day window to complete tests and replacements after 30 December 2008 for Requirements 3 and 4, which concentrates costs into a defined compliance period (Compliance).\n\n- Operational impact: while the VFR-only AFM limitation is in place the aircraft cannot legally operate in instrument meteorological conditions or at night under IFR procedures; that can be materially restrictive for some operators (Requirement 2 and Compliance timing). Removing the limitation requires passing tests or replacement, creating an incentive to complete testing quickly but also potentially pressuring owners to accept temporary solutions (Requirement 4.c allows a 90-day window to install compliant probes).\n\n- Supply and implementation risks: availability of replacement probes and qualified maintenance resources could delay compliance; the AD references specific service bulletins and a Harco test procedure, so compliance depends on access to those documents and technical capability (Requirement 3 references Eclipse and Harco Service Bulletins and a specific test procedure).\n\n- Compliance burden and recordkeeping: operators must log the checks and AFM changes; licensed pilot-owners may perform some administrative steps, but testing/replacement requires maintenance capability (Requirements 1 and 2).\n\n**Concentration of benefits and costs**\n\n- Benefits (safety) are concentrated on flight crews and passengers of affected aircraft and on system reliability for affected models.\n\n- Costs are concentrated on the owners/operators of aircraft with the affected probes and on maintenance providers who must carry out tests and repairs. The AD does not create a subsidy or financial assistance mechanism; the account of costs sits with those responsible for the aircraft.\n\n**How the AD affects private choice and market behaviour**\n\n- Aircraft owners face a clear compliance choice: identify and prove probes are unaffected or tested-and-passing, or accept operational restrictions until probes are fixed. Some operators may accelerate replacements or source probes with unaffected serial numbers to restore full operational capability sooner (this is an available compliance path under Requirement 4.a/b).\n\n- Maintenance shops may see increased short-term demand for testing and replacements. Market prices for replacement probes or maintenance slots may rise during the compliance window if supply is constrained.\n\n**Key cross-references and mechanics to note**\n\n- The AD requires following Eclipse Aviation Alert Service Bulletin SB 500-34-019, Rev C (for EA500-installed probes) and Harco Labs Service Bulletin SB-34-10-10-001 Rev F plus Harco Procedure P1149 Rev E for the heater test (Requirement 3).\n\n- The AFM limitation (Operate only under Day VFR; File only a VFR Flight Plan) may be entered by an owner/operator who holds at least a private pilot licence (Requirement 2).\n\n**Official purpose-claim and testing against it**\n\n- The AD’s stated purpose is to detect and correct improperly performing pitot/AOA probe heaters to prevent freeze-blockage and incorrect pitot/AOA indications (Background). Mechanically, the AD imposes an identification step, temporary operational limitations, a standardised heater-performance test, and mandatory replacement for failing probes. The direct costs and operational restrictions are concrete and borne by owners/operators; the AD creates an incentive to test and replace quickly to regain full operational capability. Implementation risk (parts and technician availability) and the compliance window are the main practical constraints to achieving the stated safety outcome.\n\n(Referenced sections: Applicability; Requirements 1–6; Compliance; Background.)"},"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-inst-57-harco-labs-inc-pitot-angle-of-attack-probes","history":"/api/acts/ad-inst-57-harco-labs-inc-pitot-angle-of-attack-probes/history","analysis":"/api/acts/ad-inst-57-harco-labs-inc-pitot-angle-of-attack-probes/analysis","conflicts":"/api/acts/ad-inst-57-harco-labs-inc-pitot-angle-of-attack-probes/conflicts","importantCases":"/api/acts/ad-inst-57-harco-labs-inc-pitot-angle-of-attack-probes/important-cases","documents":"/api/acts/ad-inst-57-harco-labs-inc-pitot-angle-of-attack-probes/documents"}}