{"id":"F2006B02433","name":"AD/APU/15 - GTCP 36 Series APU Load Compressor Containment","slug":"ad-apu-15-gtcp-36-series-apu-load-compressor-containment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":41689,"registerId":"commonwealth-F2006B02433-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \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.","sortOrder":0},{"sectionNumber":"AD/APU/15 GTCP 36 Series APU Load Compre","sectionType":"part","heading":"AD/APU/15 GTCP 36 Series APU Load Compressor Containment","content":"# AD/APU/15 GTCP 36 Series APU Load Compressor Containment\n\n  \n8/2000","sortOrder":1},{"sectionNumber":"Requirement: 1. APUs fitted with load co","sectionType":"part","heading":"Requirement: 1. APUs fitted with load compressor impeller P/N 3822270-4. Install either:","content":"## Requirement: 1. APUs fitted with load compressor impeller P/N 3822270-4. Install either:\n\n    (a) an external load compressor containment shield: or\n\n    (b) load compressor impeller P/N 3822270-5, in accordance with AlliedSignal Inc. SB GTCP36-49-7471 dated April 20, 1999, SB GTCP36-49-7472 dated March 31,1999, or GTCP36-49-7473 dated March 31,1999, as applicable.","sortOrder":2},{"sectionNumber":"2. APUs fitted with load compressor impe","sectionType":"part","heading":"2. APUs fitted with load compressor impeller P/N 3822270-5.","content":"## 2. APUs fitted with load compressor impeller P/N 3822270-5.\n\nInstall an external load compressor containment shield in accordance with AlliedSignal Inc. SB GTCP36-49-7471 dated April 20, 1999, SB GTCP36-49-7472 dated March 31,1999, or GTCP36-49-7473 dated March 31,1999, as applicable.\n\nNote 1: FAA AD 2000-04-24 Amendment 39-11607 refers.\n\nCompliance: 1. Unless previously accomplished, at next shop visit or within 6 months time in service after the effective date of this Directive, whichever occurs first.\n\nNote 2: For the purpose of this Directive a shop visit is defined as when the APU is inducted into an APU workshop for any reason.\n\n2. Unless previously accomplished, within 12 months time in service from the effective date of this Directive or prior to the impeller exceeding 26,000 cycles since new, whichever occurs later.\n\nThis Airworthiness Directive becomes effective on 10 August 2000.","sortOrder":3}],"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":"Scope is limited to GTCP36 APUs with the specified impeller part numbers and implements corrective actions identified in AlliedSignal service bulletins and the referenced FAA AD. The directive does not broaden applicability beyond those parts or require additional unrelated actions."},"complexity_factors":["Narrow applicability to two specific impeller part numbers (P/N 3822270-4 and P/N 3822270-5) — requires accurate parts records and inspections.","Two alternative corrective actions (install external containment shield or replace impeller) — creates choice and logistical decisions for operators.","Different compliance triggers and windows (next shop visit or within 6 months; or within 12 months or before 26,000 cycles) — requires tracking of shop events and cycle counts.","Operational dependence on manufacturer's service bulletins (AlliedSignal SB GTCP36-49-7471/7472/7473) for procedures — procedural detail outsourced to SBs.","Cross-reference to FAA AD 2000-04-24 — harmonisation and interpretation may be required for operators subject to multiple regulators.","Practical compliance costs: parts availability, installation labour and APU workshop downtime — economic and scheduling impact on operators.","Definition of 'shop visit' is specified, reducing ambiguity but still requiring administrative monitoring of APU inductions."],"plain_english_summary":"This AD requires operators of aircraft with GTCP36 APUs fitted with load-compressor impeller P/N 3822270-4 to either install an external load-compressor containment shield or replace the impeller with P/N 3822270-5. APUs already fitted with P/N 3822270-5 must have a containment shield fitted. CASA’s delegate enforces the rule and refers to AlliedSignal service bulletins. Aircraft operators pay for parts, labour and shop time; compliance deadlines are either at next shop visit or within specified months/cycle limits, changing maintenance choices and costs."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope — addressing a specific mechanical defect in a specific APU model series. The instrument has not expanded beyond its initial safety purpose of mandating containment shields and impeller replacements for the GTCP 36 series."},"complexity_factors":["Short, single-purpose directive with only 2 main requirements","Minimal defined terms (only 'shop visit' is explicitly defined in Note 2)","Straightforward conditional logic based on part numbers (P/N 3822270-4 vs P/N 3822270-5)","Two compliance timeframes with clear 'whichever occurs first/later' triggers","References to external technical documents (AlliedSignal Service Bulletins) without reproducing their content","No nested exceptions or complex cross-referencing within the instrument itself"],"plain_english_summary":"This safety order targets AlliedSignal GTCP 36-series APUs whose load-compressor impeller can break apart, sending fragments that could damage the aircraft or injure people. Owners/operators of APUs with P/N 3822270-4 or 3822270-5 must either fit a protective metal shield or replace the older impeller with the newer P/N 3822270-5; APUs already with the newer impeller still require the shield. Compliance is required within 6–12 months from August 2000."}},"importantCases":[],"_links":{"self":"/api/acts/ad-apu-15-gtcp-36-series-apu-load-compressor-containment","history":"/api/acts/ad-apu-15-gtcp-36-series-apu-load-compressor-containment/history","analysis":"/api/acts/ad-apu-15-gtcp-36-series-apu-load-compressor-containment/analysis","conflicts":"/api/acts/ad-apu-15-gtcp-36-series-apu-load-compressor-containment/conflicts","importantCases":"/api/acts/ad-apu-15-gtcp-36-series-apu-load-compressor-containment/important-cases","documents":"/api/acts/ad-apu-15-gtcp-36-series-apu-load-compressor-containment/documents"}}