{"id":"F2006B09241","name":"AD/DHC-8/82 - Autopilot Servo Engagement","slug":"ad-dhc-8-82-autopilot-servo-engagement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53144,"registerId":"commonwealth-F2006B09241-current","compilationNumber":null,"startDate":"2026-04-02","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\nBombardier (Boeing Canada/de Havilland) DHC-8 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/DHC-8/82 Autopilot Servo Engagement 2","sectionType":"part","heading":"AD/DHC-8/82 Autopilot Servo Engagement 2/2002","content":"# AD/DHC-8/82 Autopilot Servo Engagement 2/2002\n\nDM\n\nApplicability: DHC-8 Series 102, 103, 106, 201, 202, 301, 311, 314 and 315, with Serial Numbers\n\n003 through 580 inclusive.\n\nRequirement: 1. Determine through a visual inspection of the automatic flight control system, SM-300 servo drive assemblies, Part Numbers (P/N) 7002260-922 and -923, the serial numbers (S/N) of the aileron and elevator servo drives.\n\nNote 1: P/N 7002260-922 applies to both the elevator servo drive unit installed in Series 100, 200 and 300 aircraft and to the aileron servo drive unit installed in Series 300 aircraft.\n\nNote 2: P/N 7002260-923 applies to the aileron servo drive units installed in Series 100 and 200 aircraft.\n\n    2. Remove and replace aileron and elevator servo drive assemblies (P/Ns 7002260- 922 and -923) that have a serial number with the last four digits in the range from 4826 through 5935 (i.e. xxxx 4826 through xxxx 5935) with servo drive assemblies complying with the following:\n\n    If P/N 7002260-922 is removed, replace with servo drive assembly\n\nP/N 7002260-722 or with servo drive assembly P/N 7002260-922 that has a serial number with the last four digits being 4825 or lower.\n\n    b. If P/N 7002260-923 is removed, replace with servo drive assembly\n\nP/N 7002260-723 or with servo drive assembly P/N 7002260-923 that has a serial number with the last four digits being 4825 or lower.\n\nBombardier Alert Service Bulletin A8-22-18 dated 06 September 2001 or Revision A dated 18 September 2001, provides approved instructions for replacing the servo drive units.\n\n    3. Aileron and elevator servo drive assemblies (P/Ns 7002260-922 and -923) that have a serial number with the last four digits in the range from 4826 through 5935 shall not be installed in any aircraft.\n\nNote 3: Transport Canada AD CF-2001-40 refers.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Based on the text provided, this version does not materially broaden the class of affected aircraft or parts beyond the stated safety objective. It specifies a targeted inspection and replacement requirement for particular P/Ns and serial-number ranges and provides defined replacement options. There is no indication in the text that the AD expanded into unrelated equipment, new aircraft types, or additional operational rules; it refines and prescribes corrective action for the original unsafe condition (see Requirements 1–3 and referenced Bombardier service bulletin)."},"complexity_factors":["Clear, short document with three principal requirement steps (Requirements 1–3).","Multiple affected aircraft series listed (Series 102, 103, 106, 201, 202, 301, 311, 314, 315).","Applicability limited to serial numbers 003 through 580 inclusive (per aircraft serial number), adding a simple filter layer.","Part-number and serial-number logic: two P/Ns (7002260-922 and -923) with affected S/N last-four-digit range 4826–5935, and allowed replacements defined by P/N and S/N thresholds (nested but simple conditions).","Replacement options include either different P/Ns (7002260-722/-723) or same P/N with S/N <= 4825 — conditional choices increase cognitive load slightly.","Cross-reference to Bombardier Alert Service Bulletin A8-22-18 (or Revision A) for procedural detail — external dependency but typical for ADs.","Reference to Transport Canada AD CF-2001-40 (informational cross-reference).","Compliance timing is referenced to the AD’s compliance section (not reproduced here), introducing some uncertainty about exact deadlines."],"plain_english_summary":"**What this directive does**\n\n- This Airworthiness Directive (AD) orders operators of certain Bombardier (De Havilland) DHC-8 (Dash 8) aeroplanes to inspect and, if necessary, replace specific autopilot servo drive units (the SM-300 units that move the ailerons and elevator).\n\n- The AD applies to DHC-8 Series 102, 103, 106, 201, 202, 301, 311, 314 and 315 aeroplanes with serial numbers 003 through 580 inclusive (Applicability).\n\n- Mechanically, it requires three steps:\n  - 1) Visually inspect the automatic flight control system to identify the serial numbers of the aileron and elevator SM-300 servo drive assemblies (Part Numbers P/N 7002260-922 and P/N 7002260-923) (Requirement 1).\n  - 2) Remove and replace any servo drive whose serial number’s last four digits fall between 4826 and 5935 (inclusive). Replacements must be either:\n    - for P/N 7002260-922: a unit P/N 7002260-722, or another P/N 7002260-922 whose last four serial digits are 4825 or lower; or\n    - for P/N 7002260-923: a unit P/N 7002260-723, or another P/N 7002260-923 whose last four serial digits are 4825 or lower. The Bombardier Alert Service Bulletin A8-22-18 (or Revision A) gives approved replacement instructions (Requirement 2).\n  - 3) Do not install any servo drive (P/Ns 7002260-922 or -923) whose last four serial digits are in the 4826–5935 range on any aircraft (Requirement 3).\n\n**Who is affected**\n\n- Aircraft owners/operators of the listed DHC-8 series and serial number range must carry out the inspection and replacements and must ensure the prohibited serial-numbered parts are not installed. Maintenance organisations performing the work will be directly involved. Parts suppliers and the OEM may be affected because of replacement part demand and approval of replacement units.\n\n**Why it matters / stated purpose**\n\n- The AD is issued to correct an identified unsafe condition in the autopilot servo drives. That is the stated purpose in the AD (see background and Requirement sections). The directive prescribes an inspection and removal/replacement program and a prohibition on installing affected parts to control that safety risk.\n\n**Practical effects, costs and incentives**\n\n- Who pays: aircraft owners/operators pay for the inspection, any removal and replacement labour, and replacement parts. Downtime for aircraft during maintenance also has an economic cost to operators.\n\n- Who decides: the CASA delegate issues and enforces the AD; operators must comply according to the AD’s compliance timetable (see compliance section referenced in the AD).\n\n- Behaviour change mandated: operators must inspect serial numbers, remove and replace affected servo drives, and ensure prohibited serial-numbered units are not fitted to any aircraft (Requirements 1–3).\n\n- Trade-offs and implementation risks: the AD trades operating and maintenance cost (parts, labour, grounding time) for reduced safety risk. Implementation risks include parts availability (especially for the approved replacement P/Ns 7002260-722 and -723), scheduling downtime for fleets, and accurate identification of serial numbers during inspection. The AD refers to an OEM service bulletin for approved instructions, which channels the technical method for compliance (Requirement 2; Bombardier Alert Service Bulletin A8-22-18).\n\n- Effects on private enterprise: maintenance shops and parts suppliers are required to perform or supply the approved replacements. The OEM or authorised suppliers who can provide replacement P/Ns (7002260-722/-723) may capture concentrated demand; operators face diffuse costs across the affected fleet.\n\n**Implementation and compliance notes**\n\n- The AD cross-references Bombardier Alert Service Bulletin A8-22-18 (or Revision A) for detailed replacement instructions (Requirement 2).\n\n- The AD explicitly prohibits installation of the affected serial-numbered units on any aircraft (Requirement 3), which prevents re-use of removed parts falling in the listed serial-number range.\n\n**Source-claimed purpose versus practical implications**\n\n- The AD claims its measures are necessary to correct an unsafe condition. Practically, that claim implies ongoing costs to operators and a requirement to follow OEM-prescribed procedures. The immediate, concrete effects are: increased maintenance work where affected parts are present; replacement with specified alternate P/Ns or earlier serial-numbered units; and a formal ban on reinstalling the identified serial-numbered units. These are mechanical, enforceable measures with predictable compliance burdens (inspection, replacement, record keeping) and with potential operational disruption while work is done."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope as a targeted safety intervention for specific defective autopilot components. It has not expanded beyond its original purpose of addressing the identified unsafe condition in the DHC-8 servo drive assemblies."},"complexity_factors":["Highly specific technical scope — applies only to two part numbers (P/N 7002260-922 and -923) on specific aircraft serial numbers","Precise serial number range requirement (last four digits 4826–5935) creates a narrow conditional trigger","Multiple cross-references to manufacturer documentation (Bombardier Alert Service Bulletin A8-22-18 and Revision A)","Nested replacement logic with two alternative compliant parts for each removed unit","Short, self-contained document with minimal defined terms — essentially a single operational instruction with technical specifications"],"plain_english_summary":"Owners and operators of Bombardier DHC‑8 Series 100/200/300 aircraft (serials 003–580) must inspect autopilot servo drive units and remove any with serial numbers ending 4826–5935. CASA mandates replacement of affected units with approved parts and forbids reinstalling the faulty drives.\n\nThis AD addresses a manufacturing defect that can cause unexpected autopilot disengagement or failure to engage, preventing possible loss of control by removing defective components."},"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-dhc-8-82-autopilot-servo-engagement","history":"/api/acts/ad-dhc-8-82-autopilot-servo-engagement/history","analysis":"/api/acts/ad-dhc-8-82-autopilot-servo-engagement/analysis","conflicts":"/api/acts/ad-dhc-8-82-autopilot-servo-engagement/conflicts","importantCases":"/api/acts/ad-dhc-8-82-autopilot-servo-engagement/important-cases","documents":"/api/acts/ad-dhc-8-82-autopilot-servo-engagement/documents"}}