{"id":"F2008L02668","name":"AD/DHC-8/102 Amdt 1 - Pitot Static System Contamination","slug":"ad-dhc-8-102-amdt-1-pitot-static-system-contamination","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":74705,"registerId":"commonwealth-F2008L02668-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Bombardier (Boeing Canada/De Havilland) ","sectionType":"division","heading":"Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes","content":"### Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\n| AD/DHC-8/102 Amdt 1 | Pitot Static System Contamination | 8/2008 |\n| ------------------- | --------------------------------- | ------ |\n\n| Applicability: | Models DHC-8-400, DHC-8-401 and DHC-8-402, Serial Numbers (S/N) 4003 through 4154. |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement: | 1. Clean the drain hole of all the pitot static probes in accordance with Dash 8 Q400 Aircraft Maintenance Manual (AMM), PSM 1-84-2, Task 20-00-40-170-801 as follows: |\n| | Note 1: Aircraft Serial Numbers 4147 to 4154 have had the new design probes installed during production (Bombardier ModSum 4-113525), cleaning of pitot static probe drain hole is not required on those aircraft. |\n| | a. Clean the drain holes in accordance with paragraph 4.B., Procedure 2, sub-paragraph (1) to (3) of the AMM task. |\n| | b. After cleaning, examine the drain hole for blockage in accordance with Paragraph 4.A., Procedure 1 of the AMM task. |\n| | c. If the drain hole of any pitot static probe is blocked, repeat the Requirement 1.a. and 1.b. cleaning and examination procedure of this Directive on the affected pitot static probe. |\n| | 2. For aircraft S/N 4003, 4004, 4006, 4008 through 4114, clean the pitot lines in accordance with Dash 8 Q400 AMM, PSM 1-84-2, Task 34-11-00-170-801 of each aircraft that has not been modified in accordance with Requirement 3. |\n| | 3. For aircraft S/N 4003, 4004, 4006, 4008 through 4114, incorporate Bombardier ModSum 4-113488 to modify the pitot static system tubing for improved water drainage. Bombardier Service Bulletin (SB) 84-34-59, Revision D, dated 27 July 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada provides approved instructions for incorporating ModSum4-113488. |\n| | Note 2: Incorporation of Modsum 4-113488, before the effective date of this Amendment, in accordance with Revision A, B or C of SB 84-34-59 also satisfies this Requirement. |\n\n| | Accomplishment of the Requirement 3 modification constitutes terminating action to the Requirement 2 repetitive pitot line cleaning. |\n| --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| | 4. For aircraft Serial Numbers 4003 through 4146 - |\n| | a. Incorporate Bombardier ModSum 4-113530 to replace the left side primary pitot probe with a new design. Bombardier SB 84-34-90, Revision B, dated 3 January 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada provides approved instructions for incorporating ModSum 4-113530. |\n| | Note 3: Incorporation of Modsum 4-113530, before the effective date of this Amendment, in accordance with the initial issue or Revision A of Bombardier SB84-34-90 also satisfies this Requirement. |\n| | b. Incorporate Bombardier ModSum 4-113531 to replace the right side primary pitot probe with a new design. Bombardier SB 84-34-91, Revision B, dated 10 January 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada provides approved instructions for incorporating ModSum 4-113531. |\n| | Note 4: Incorporation of Modsum 4-113531, before the effective date of this Amendment, in accordance with the initial issue or Revision A of Bombardier SB84-34-91 also satisfies this Requirement. |\n| | 5. For aircraft Serial Numbers 4003 through 4154, incorporate Bombardier ModSum 4-113526 to replace the standby pitot probe with a new design. Bombardier SB 84-34-93, Revision A, dated 23 February 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada, provides approved instructions for incorporating ModSum 4-113526. |\n| | Note 5: Incorporation of Modsum 4-113526, before the effective date of this Amendment, in accordance with the initial issue of Bombardier SB 84-34-93 also satisfies this Requirement. |\n| | 6. For aircraft Serial Numbers 4115 through 4145, carry out a one-time inspection for the correct installation of standby pitot static system tube assemblies and perform any necessary rectification, according to the Accomplishment Instructions of the Initial Issue of Bombardier SB 84-34-99, dated 4 April 2007, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. |\n| | Accomplishment of the Requirement 4, 5 and 6 modifications constitutes terminating action to the Requirement 1 repetitive pitot static probe drain hole cleaning and inspections. |\n\n| | Note 6: Transport Canada AD CF-2005-15R1 refers. |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | For Requirement 1 - Initially, within 30 days after 4 August 2005 (the effective date of the original issue of this Directive) and thereafter at intervals not to exceed 70 hours time in service (TIS) until Requirements 4, 5 and 6 are accomplished. |\n| | For Requirement 2 - Initially, within 30 days after 4 August 2005 the effective date of the original issue of this directive) and thereafter at intervals not to exceed 600 hours TIS until the aircraft is modified in accordance with Requirement 3. |\n| | For Requirement 3 - Within 6 000 hours TIS after the effective date of this Amendment. |\n| | For Requirement 4 - Within 6 000 hours TIS after the effective date of this Amendment. |\n| | For Requirement 5 - Within 6 000 hours TIS after the effective date of this Amendment. |\n| | For Requirement 6 - Prior to accomplishing Requirement 5. |\n| | This Amendment becomes effective on 31 July 2008. |\n| Background: | Incidents of airspeed mismatch between the pilot, co-pilot and standby airspeed indication have been reported to Transport Canada. These events are believed to be caused by contamination within the pitot lines and/or blockage within the pitot static probes. Blockage of a probe’s pitot drain may allow sufficient moisture to enter the probe’s internal pitot line such that freezing may occur under certain conditions, causing a blockage to the pitot line. |\n| | The Original issue of this Directive was an interim action to avoid the potential for erroneous airspeed information, by mandating the periodic cleaning of the pitot static probe drain hole and the pitot lines. |\n| | To mitigate potential blockage of the pitot static system, Bombardier has introduced modifications to improve the water drainage capabilities of the pitot static system and the freeze protection capabilities of the pitot probes. Therefore, this Amendment is issued to mandate the incorporation of the above-mentioned modifications as terminating action to the repetitive maintenance requirements mandated by the original issue of this Directive. |\n\n| | The original issue of this Directive became effective on 4 August 2005. |\n| --- | ----------------------------------------------------------------------- |\n\n![](image.001.png) \nJames Coyne \nDelegate of the Civil Aviation Safety Authority\n\n20 June 2008","sortOrder":0},{"sectionNumber":"AD/DHC-8/102 Amdt 1","sectionType":"part","heading":"AD/DHC-8/102 Amdt 1","content":"## AD/DHC-8/102 Amdt 1","sortOrder":1},{"sectionNumber":"Pitot Static System Contamination","sectionType":"part","heading":"Pitot Static System Contamination","content":"## Pitot Static System Contamination","sortOrder":2},{"sectionNumber":"8/2008","sectionType":"part","heading":"8/2008","content":"## 8/2008","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":7,"scope_assessment":{"changed":true,"description":"The Amendment changes scope from the original interim measure (periodic cleaning to avoid erroneous airspeed) to mandatory incorporation of specific design modifications as terminating action to repetitive maintenance. The Background states the original issue was interim cleaning; the Amendment mandates ModSums/SBs to eliminate the recurring cleaning/inspection requirements (Background; Requirements 3–6; ‘terminating action’ notes)."},"complexity_factors":["Multiple, serial‑number–specific applicability (S/N ranges 4003–4154 with different requirements/exceptions) (Applicability; Requirements 1–6).","Layered actions: short‑interval repetitive maintenance (cleaning/inspections) combined with longer‑term mandatory hardware modifications (Requirements 1–3, 4–6; Compliance).","Interdependent terminating actions: certain ModSums terminate specific repetitive tasks (e.g. Req 3 terminates Req 2; Req 4–6 terminate Req 1), requiring tracking of modification status per aircraft (Requirements: ‘terminating action’ notes).","Multiple referenced modification kits and Service Bulletins (ModSum 4‑113488/4‑113525/4‑113530/4‑113531/4‑113526 and SBs 84‑34‑59/90/91/93/99) which must be followed in approved revisions (Requirements 3–6).","Varied compliance timeframes and intervals (initial 30 days, repeat intervals of 70 hrs TIS or 600 hrs TIS, and longer 6,000 hrs TIS windows for modifications; some ‘prior to’ conditions) increasing scheduling complexity (Compliance).","Approval and discretion point: acceptable SB revisions must be approved by the Chief, Continuing Airworthiness, Transport Canada, creating administrative oversight and potential variance (Requirements 3–6).","Exceptions/notes and pre‑compliance credit: prior incorporation of certain ModSums or SB revisions satisfies requirements, requiring records verification (Notes 1–6; Requirements).","Technical and safety sensitivity: pitot system cleanliness, drainage and freeze‑protection work requires specialised procedures from the Aircraft Maintenance Manual, creating skill and tooling requirements (Requirement 1; AMM task references).","Cross‑jurisdictional reference: this AD refers to a Transport Canada AD (CF‑2005‑15R1), potentially affecting interpretation and compliance documentation (Note 6; Background)."],"plain_english_summary":"This directive requires operators of Bombardier DHC‑8‑400 series aeroplanes (S/N 4003–4154) to perform periodic pitot probe and pitot‑line cleaning and inspections, and to fit specified manufacturer design modifications (ModSums via Bombardier Service Bulletins) that improve drainage and freeze protection. (Applicability; Requirements 1–6.)\n\nOperators pay for and carry out the work; the modifications must follow Bombardier SB instructions approved by the Chief, Continuing Airworthiness, Transport Canada, within the flight‑hour deadlines set out. (Compliance; Requirements 3–6.)"},"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":4,"scope_assessment":{"changed":false,"description":"This is an amendment to an existing Airworthiness Directive. The original directive (effective August 2005) mandated repetitive cleaning as an interim safety measure. This Amendment 1 adds permanent modification requirements that terminate the repetitive cleaning, which is consistent with the original intent of addressing pitot-static contamination. The scope has not expanded beyond the original safety purpose."},"complexity_factors":["Multiple serial number ranges with different requirements (S/N 4003-4154, with subsets 4003-4146, 4115-4145, 4147-4154, and 4003-4114)","Six distinct requirements with interdependencies (Requirements 4, 5, and 6 terminate Requirement 1; Requirement 3 terminates Requirement 2)","Cross-references to external documents (Bombardier Service Bulletins and Aircraft Maintenance Manual tasks)","Conditional logic based on prior modifications (Notes 1-5 specify alternative compliance paths if modifications already performed)","Multiple compliance timeframes (30 days, 70 hours TIS, 600 hours TIS, 6,000 hours TIS, and 'prior to' dependencies)","Technical aviation terminology requiring domain knowledge (pitot-static, TIS/time in service, ModSum, Service Bulletins)"],"plain_english_summary":"This CASA Airworthiness Directive targets Bombardier DHC-8-400 (Q400) aircraft, S/N 4003–4154, requiring owners/operators to stop pitot-static moisture contamination that can freeze and cause false airspeed indications.\n\nUntil permanent fixes are installed (new pitot probes, standby probe, improved tubing/drains and inspections), operators must clean/inspect pitot probe drains every 70 flight hours and clean internal pitot lines every 600 hours for older aircraft. The changes prevent erroneous airspeed and related loss-of-control risks."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-102-amdt-1-pitot-static-system-contamination","history":"/api/acts/ad-dhc-8-102-amdt-1-pitot-static-system-contamination/history","analysis":"/api/acts/ad-dhc-8-102-amdt-1-pitot-static-system-contamination/analysis","conflicts":"/api/acts/ad-dhc-8-102-amdt-1-pitot-static-system-contamination/conflicts","importantCases":"/api/acts/ad-dhc-8-102-amdt-1-pitot-static-system-contamination/important-cases","documents":"/api/acts/ad-dhc-8-102-amdt-1-pitot-static-system-contamination/documents"}}