{"id":"F2006L02984","name":"AD/BEECH 400/27 - Generator Control Unit","slug":"ad-beech-400-27-generator-control-unit","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":60263,"registerId":"commonwealth-F2006L02984-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Beechcraft 400 Series Aeroplanes","sectionType":"division","heading":"Beechcraft 400 Series Aeroplanes","content":"### Beechcraft 400 Series Aeroplanes\n\n| AD/BEECH 400/27 | Generator Control Unit | 10/2006 |\n| --------------- | ---------------------- | ------- |\n\n| Applicability: | Raytheon (Beech) Model aeroplanes as follows:                                                                                                                                                                                                                                                                                                       |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|                | 400 series, with serial numbers (S/N) RJ-1 through RJ-65 inclusive, on which kit part number (P/N) 128-3004-1 P or 128-3004-3 P has been incorporated (Lucas Aerospace/Goodrich Direct Current (DC) Starter Generator).                                                                                                                             |\n|                | 400A series, with S/N RK-1 through RK-23 inclusive, on which kit P/N 128-3004-1 P or 128-3004-3 P has been incorporated (Lucas Aerospace/Goodrich DC Starter Generator).                                                                                                                                                                            |\n| Requirement:   | 1. Review the aeroplane logbook, in accordance with the Accomplishment instructions of Raytheon Service Bulletin (SB) SB 24-3713, dated November 2005, to determine whether generator control unit (GCU) installation kit, P/N 128-3001-1 P or 128-3001-3 P, is installed.                                                                          |\n|                | 2. If, as a result of the Requirement 1 determination, a GCU installation kit P/N 128-3001-1 P or 128-3001-3 P is not found to be installed or if the kit P/N cannot be conclusively determined, replace the Shinko GCUs with new Lucas Aerospace/Goodrich GCUs (installation kit P/N 128-3001-1 P or 128-3001-3 P), in accordance with SB 24-3713. |\n|                | 3. If, as a result of the Requirement 1 determination, any GCU installation kit, P/N 128-3001-1 P or 128-3001-3 P is found installed, inspect to determine the P/ N of both GCUs, in accordance with SB 24-3713 and carry out Requirement 4 or 5 as applicable.                                                                                     |\n|                | 4. Both GCUs have P/N 45AS88801-19 or -25 - Inspect to determine the P/N of both current sense transformers on the lower inboard quadrant of the left-hand and right-hand engine inlets, in accordance with SB 24-3713.                                                                                                                             |\n|                | a. If both current sense transformers have P/N 45AS88801-21, no further action is required by this Directive.                                                                                                                                                                                                                                       |\n|                | b. If either current sense transformer is not identified with P/N 45AS88801-21, replace the current sense transformer with a new transformer, P/N 45AS88801-21, in accordance with SB 24-3713.                                                                                                                                                      |\n\n|             | 5. Either GCU does not have P/N 45AS88801-19 or -25 - Replace the GCU with a new GCU, P/N 45AS88801-19 or -25, and inspect to determine the P/N of both current sense transformers on the lower in-board quadrant of the left-hand and right-hand engine inlets, in accordance with SB 24-3713.                                 |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | a. If both current sense transformers have P/N 45AS88801-21, no further action is required by this Directive.                                                                                                                                                                                                                   |\n|             | b. If either current sense transformer is not identified with P/N 45AS88801-21, replace the current sense transformer with a new transformer, P/N 45AS88801-21, in accordance with SB 24-3713.                                                                                                                                  |\n|             | Later revisions of the above SB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2006-15-16, are considered acceptable for compliance with the equivalent Requirements of this Directive.                                                             |\n|             | Note: FAA AD 2006-15-16 Amdt 39-14697 refers.                                                                                                                                                                                                                                                                                   |\n| Compliance: | For Requirements 1, 2, 3, 4 and 5 - Within 200 hours time in service or 6 months after the effective date of this Directive, whichever occurs first.                                                                                                                                                                            |\n|             | This Airworthiness Directive becomes effective on 28 September 2006.                                                                                                                                                                                                                                                            |\n| Background: | The FAA has reports of over-voltage conditions of the direct current (DC) starter generator. This Directive requires, among other actions, reviewing the aeroplane logbook to determine whether certain generator control unit (GCU) installation kits are installed and, if necessary, replacing any incorrect GCU.            |\n|             | The Directive is issued to prevent such over-voltage conditions due to the incompatibility between certain GCUs, which could result in the loss of normal electrical power, damage to some electrical components, or blown fuses during flight, together with a possible unrecoverable loss of some or all essential equipment. |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n14 August 2006","sortOrder":0},{"sectionNumber":"AD/BEECH 400/27","sectionType":"part","heading":"AD/BEECH 400/27","content":"## AD/BEECH 400/27","sortOrder":1},{"sectionNumber":"Generator Control Unit","sectionType":"part","heading":"Generator Control Unit","content":"## Generator Control Unit","sortOrder":2},{"sectionNumber":"10/2006","sectionType":"part","heading":"10/2006","content":"## 10/2006","sortOrder":3}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive with focused scope. It addresses a specific safety defect (over-voltage conditions) in a defined aircraft population with specific serial numbers and modification status. The requirements follow the typical AD structure of inspection/replacement based on findings, without scope creep beyond the original safety purpose."},"complexity_factors":["Multiple conditional branches (Requirements 1-5 with nested sub-requirements 4a/4b and 5a/5b)","Specific part number dependencies (8 distinct part numbers referenced: 128-3004-1 P, 128-3004-3 P, 128-3001-1 P, 128-3001-3 P, 45AS88801-19, 45AS88801-25, 45AS88801-21, plus Shinko GCUs)","Serial number applicability ranges (RJ-1 through RJ-65, RK-1 through RK-23)","Cross-reference to external technical document (Raytheon Service Bulletin SB 24-3713)","Reference to foreign regulatory equivalent (FAA AD 2006-15-16) and AMOC provisions","Dual compliance timeframe calculation (200 hours time-in-service OR 6 months, whichever first)"],"plain_english_summary":"This CASA Airworthiness Directive applies to Beechcraft 400 (RJ‑1–RJ‑65) and 400A (RK‑1–RK‑23) jets fitted with the Lucas/Goodrich DC starter generator kit. It requires owners/operators to verify the Generator Control Units (GCUs), replace incompatible Shinko GCUs with approved Lucas/Goodrich units, and inspect/replace current‑sense transformers if needed.  \n\nThe action prevents dangerous over‑voltage events that can cause electrical failures or permanent loss of essential equipment. Compliance is required within 200 flight hours or 6 months of 28 Sep 2006."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The Directive's scope targets the same subset of aircraft and equipment identified in the source (specific serial ranges and kit P/Ns) and mirrors the FAA AD referenced. It imposes a one-time inspection/repair obligation with a fixed compliance window and does not broaden applicability beyond those aircraft or add ongoing reporting obligations (see Applicability, Requirements 1–5, Compliance, and FAA AD note)."},"complexity_factors":["Applicability is limited to particular serial-number ranges and only where specified starter-generator kit P/Ns have been incorporated (Applicability section).","Multiple conditional branches in Requirements 1–5: logbook check, then different follow-up actions depending on presence/part-number of GCU kits and current-sense transformers (Requirement 1–5).","Procedural work is defined by an external service document (Raytheon SB 24-3713); compliance requires following that SB for inspections and replacements (Requirement text referencing SB 24-3713).","Numerous precise part numbers must be verified and, if mismatched, replaced (e.g. GCU P/Ns 128-3001-1P/128-3001-3P; GCU P/Ns 45AS88801-19/-25; transformer P/N 45AS88801-21) (Requirements 2–5).","A firm compliance window (200 flight hours or 6 months) creates scheduling pressure for operators and maintenance providers (Compliance section).","Acceptance of later SB revisions as FAA-approved Alternate Methods of Compliance introduces an external approval pathway and potential variability in acceptable procedures (AMOC note / FAA AD reference).","Technical nature of inspections and parts replacement implies need for qualified maintenance personnel and access to parts and SB procedures (Requirements referencing replacements in accordance with SB 24-3713)."],"plain_english_summary":"This Airworthiness Directive requires operators of specified Beechcraft 400/400A aeroplanes (identified serial ranges fitted with certain starter-generator kits) to check the logbook for a particular generator control unit (GCU) kit and, if absent or inconclusive, install the specified Lucas/Goodrich GCUs. Where certain GCU or current-sense transformer part numbers are incorrect, those parts must be replaced per Raytheon Service Bulletin SB 24-3713. CASA says the measure prevents DC starter-generator over-voltage; operators must complete work within 200 flight hours or six months."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-400-27-generator-control-unit","history":"/api/acts/ad-beech-400-27-generator-control-unit/history","analysis":"/api/acts/ad-beech-400-27-generator-control-unit/analysis","conflicts":"/api/acts/ad-beech-400-27-generator-control-unit/conflicts","importantCases":"/api/acts/ad-beech-400-27-generator-control-unit/important-cases","documents":"/api/acts/ad-beech-400-27-generator-control-unit/documents"}}