{"id":"F2007L04228","name":"AD/CF6/68 - Compressor Discharge Pressure Spring","slug":"ad-cf6-68-compressor-discharge-pressure-spring","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":70437,"registerId":"commonwealth-F2007L04228-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"General Electric Turbine Engines - CF6 S","sectionType":"division","heading":"General Electric Turbine Engines - CF6 Series","content":"### General Electric Turbine Engines - CF6 Series\n\n| AD/CF6/68 | Compressor Discharge Pressure Spring | 12/2007 |\n| --------- | ------------------------------------ | ------- |\n\n```html\n

Applicability:

General Electric Company Aircraft Engine Group (GEAE) CF6-45A, 45A2, -50A,
-50C, -50CA, -50C1, -50C2, -50C2B, -50C2D, -50C2F, -50C2R, -50E, -50E1, -50E2, and -50E2B turbofan engines that have a main engine control (MEC) with a part number (P/ N) specified in Table 1 of this AD installed.

Note 1: These engines are installed on, but not limited to, Airbus A300 series airplanes, McDonnell Douglas DC-10, KC-10, and MD-10 series airplanes, and Boeing 747 series aeroplanes.

Table 1. - Affected Woodward and GEAE
P/Ns for MECs by Engine Model Series

Engine Model Series

Woodward P/N

GEAE P/N

CF6-50A, -50C, -50CA,
-50C1, -50C2, 50C2B,
-50C2D, -50C2F, -50C2R

8062-275

9070M55P42

\"\"

8062-279

9070M55P44

\"\"

8062-287

9070M55P49

\"\"

8062-289

9070M55P51

\"\"

8062-819

9070M55P101

\"\"

8062-822

9070M55P102

\"\"

8062-824

9070M55P103

\"\"

8062-823

9070M55P104

\"\"

8062-826

9070M55P105

\"\"

8062-827

9070M55P106

\"\"

8062-828

9070M55P107

\"\"

8062-829

9070M55P108

CF6-45A, -45A2, -50E,
-50E1, -50E2, -50E2B

8062-276

9187M29P10

\"\"

8062-280

9187M29P11

\"\"

8062-290

9187M29P14

\n```\n\n```html\n

\"\"

8062-291

9187M29P15

\"\"

8062-817

9187M29P100

\"\"

8062-820

9187M29P101

\"\"

8062-896

9187M29P22

\"\"

8062-897

9187M29P23

\"\"

8062-898

9187M29P20

\"\"

8062-899

9187M29P21

Requirement:

1. For CF6-50A model engines and -50C series engines that have an MEC that has a P/N listed in Table 1 of this AD, replace the compressor discharge pressure (CDP) restoring spring assembly as follows in Table 2 of this AD.

Table 2. - Compliance Schedule for CF6-50A and -50C Engines

If the CDP restoring spring assembly in your MEC

Then

By

Use

(1) Was already replaced using GEAE CF6-50 S/B 73-0119, dated
21 March 2005.

Re-mark the MEC.

The next time the MEC is routed for repair such as the next MEC shop visit.

Paragraph 3.A. of the Accomplishment Instructions of SB No. CF6-50 S/B 73-0119, Revision 02, dated
9 March 2007.

(2) Was already replaced within 10,000 or fewer hours time-in-service (TIS) before the effective date of this AD, and the replacement spring assembly (P/N 3018-248) had zero hours TIS.

Replace the spring assembly and re-mark the MEC.

The first MEC shop visit or engine shop visit after the MEC exceeds 10,000 hours TIS, but do not exceed 20,000 hours TIS.

Paragraph 3.A. of the Accomplishment Instructions of SB No. CF6-50 S/B 73-0119, Revision 02.

(3) Has more then 10,000 hours TIS.

Replace the spring assembly and re-mark the MEC.

The next MEC shop visit or engine shop visit whichever occurs first.

Paragraph 3.A. of the Accomplishment Instructions of SB No. CF6-50 S/B 73-0119, Revision 02.

\n```\n\n```html\n

2. For CF6-45A series and -50E series engines that have an MEC that has a P/N listed in Table 1 of this AD, replace the CDP restoring spring assembly as follows in Table 3 of this AD.

Table 3. - Compliance Schedule for CF6-45A and -50E Engines

If the CDP restoring spring assembly in your MEC

Then

By

Use

(1) Was already replaced within 10,000 or fewer hours time-in-service (TIS) before the effective date of this AD, and the replacement spring assembly (P/N 3018-248) had zero hours TIS.

Replace the spring assembly and re-mark the MEC.

The first MEC shop visit or engine shop visit after the MEC exceeds 10,000 hours TIS, but do not exceed 20,000 hours TIS.

Paragraph 3.A. of the Accomplishment Instructions of SB No. CF6-50 S/B 73-0120, dated 21 March 2007.

(2) Has more then 10,000 hours TIS.

Replace the spring assembly and re-mark the MEC.

The next MEC shop visit or engine shop visit whichever occurs first.

Paragraph 3.A. of the Accomplishment Instructions of SB No. CF6-50 S/B 73-0120.

Definition: For the purpose of this AD, a shop visit is induction of the engine or MEC into the shop for any cause.

3. Do not install an MEC that:

a) Has not complied with SB No. CF6-50 S/B 73-0119, Revision 02, or earlier revision, or SB No. CF6-50 S/B 73-0120; or

b) Has not had the CDP restoring spring replaced with a spring assembly, P/N 3018-248, or FAA-approved equivalent spring assembly, within the previous 10,000 hours of MEC operation.

Note 2: FAA AD 2007-19-06 Amdt 39-15196 dated 7 September 2007 refers.

Compliance:

1. As detailed in Table 2 of this AD.

2. As detailed in Table 3 of this AD.

3. From the effective date of this AD.

\n```\n\n| | This Airworthiness Directive becomes effective on 22 November 2007. |\n| ----------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Background: | The FAA reports that there have been five events involving fractured CDP restoring spring assembly. The issuing of this AD is intended to prevent loss of engine thrust control that could lead to loss of control of the aeroplane. |\n\n![](image.002.png) \nDavid Punshon \nDelegate of the Civil Aviation Safety Authority\n\n2 October 2007","sortOrder":0},{"sectionNumber":"AD/CF6/68","sectionType":"part","heading":"AD/CF6/68","content":"## AD/CF6/68","sortOrder":1},{"sectionNumber":"Compressor Discharge Pressure Spring","sectionType":"part","heading":"Compressor Discharge Pressure Spring","content":"## Compressor Discharge Pressure Spring","sortOrder":2},{"sectionNumber":"12/2007","sectionType":"part","heading":"12/2007","content":"## 12/2007","sortOrder":3}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The AD applies to the MEC part numbers and CF6 engine models listed and prescribes replacement timing, re‑marking, and installation prohibitions. The text gives no indication that the scope departs from the stated intent to address fractured CDP spring assemblies; it stays focused on listed MECs, the replacement part (P/N 3018‑248 or FAA‑approved equivalent), and the compliance schedules referenced to the specified service bulletins."},"complexity_factors":["Large, specific parts list (many Woodward and GEAE MEC P/Ns across CF6-45A and CF6-50 variants) requiring careful parts identification (Table 1).","Multiple, conditional compliance schedules (Tables 2 and 3) that depend on prior replacement history and accumulated hours time‑in‑service (TIS) (10,000 / 20,000 hour thresholds).","Shop‑visit trigger language: timing often tied to 'next MEC shop visit or engine shop visit', requiring maintenance planning and record checks.","Requirement to re‑mark MECs after compliance (administrative tracking burden).","Prohibition on installing non‑compliant MECs or MECs not serviced within 10,000 hours (affects spare parts management and procurement).","Cross‑references to specific Service Bulletins (SB No. CF6‑50 S/B 73‑0119 and 73‑0120, including Revision 02) for accomplishment instructions—dependency on external documents.","Part‑number specific replacement (spring assembly P/N 3018‑248) or FAA‑approved equivalent—limits substitute options without approval.","Effective date and linkage to FAA AD 2007‑19‑06 create synchronisation and potential international compliance coordination.","Operational impact concentrated on operators of listed airframes/engines and maintenance organisations responsible for shop visits and recordkeeping."],"plain_english_summary":"This Airworthiness Directive requires operators to replace the compressor discharge pressure (CDP) restoring spring assembly in specified Woodward and GE main engine controls (MEC P/Ns listed) on CF6-45A and CF6-50 series engines according to the schedules in Tables 2–3, to re-mark MECs after work, and to prohibit installing MECs that haven’t complied or whose spring hasn’t been replaced within 10,000 hours. The FAA states the rule aims to prevent fractured springs that could cause loss of engine thrust control."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":6,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific mechanical defect in a defined set of engine models. The detailed part number tables and tiered compliance schedules are typical for aviation safety directives and do not represent scope creep beyond the original safety purpose of preventing CDP spring failures."},"complexity_factors":["Multiple nested condition tables (Tables 2 and 3) with three different compliance paths depending on prior maintenance history and flight hours","Extensive part number cross-referencing — Table 1 lists 21 different manufacturer part numbers across two engine series","Time-in-service (TIS) calculations required for compliance deadlines, with sliding windows (10,000-20,000 hour ranges)","Dual reference system requiring cross-checking against FAA AD 2007-19-06 and GE Service Bulletins (SB 73-0119 Rev 02 and SB 73-0120)","Conditional installation prohibition (Requirement 3) creating a rolling compliance obligation — parts become illegal to install based on age since last replacement","Definition of 'shop visit' required for interpretation of compliance timing"],"plain_english_summary":"This AD from CASA requires operators of certain General Electric CF6 turbofan engines to replace a defective compressor discharge pressure spring in the main engine control unit to prevent spring fracture and loss of thrust control. \n\nIt affects airlines using listed CF6 models on large jets, mandates part replacement and marking, limits use of non‑compliant units, and is legally enforceable to prevent engine failures and potential loss of aircraft control."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cf6-68-compressor-discharge-pressure-spring","history":"/api/acts/ad-cf6-68-compressor-discharge-pressure-spring/history","analysis":"/api/acts/ad-cf6-68-compressor-discharge-pressure-spring/analysis","conflicts":"/api/acts/ad-cf6-68-compressor-discharge-pressure-spring/conflicts","importantCases":"/api/acts/ad-cf6-68-compressor-discharge-pressure-spring/important-cases","documents":"/api/acts/ad-cf6-68-compressor-discharge-pressure-spring/documents"}}