# AD 2011-07-01: Forward and aft centerbodies

- Type: Airworthiness directive
- Status: Current
- Products: General Electric CF6-45A, CF6-45A2, CF6-50A, CF6-50C, CF6-50C1, CF6-50C2, CF6-50C2B, CF6-50C2D, CF6-50CA, CF6-50E, CF6-50E1, CF6-50E2 and 1 more
- Effective: April 22, 2011
- Published: March 18, 2011, 76 FR 14796–14797
- Issued: March 14, 2011
- Issued as: Final rule
- Supersedes: [AD 2009-04-17](https://openairdocs.org/ad/2009-04-17)
- Superseded by: Nothing supersedes this AD
- Product type: Engine
- Amendment: 39-16638
- Docket: FAA-2006-24145 (https://www.regulations.gov/docket/FAA-2006-24145)
- Project: 2006-NE-06-AD
- Registered aircraft: 21 may be affected, by airframe or engine model (OpenAirDocs)
- Official PDF: https://openairdocs.org/files/sha256/a5/bb/a5bb9e57fe007a0fec7265c42965d263c19fdb972d62c12822ca7f002cb00008 (from https://www.govinfo.gov/content/pkg/FR-2011-03-18/pdf/2011-6300.pdf)
- Federal Register: https://www.federalregister.gov/documents/2011/03/18/2011-6300/airworthiness-directives-general-electric-company-cf6-45-and-cf6-50-series-turbofan-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/38CF590084595D2486257857004CBF92.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/2011-07-01

## Summary

We are superseding an existing airworthiness directive (AD) for General Electric Company (GE) CF6-45 and CF6-50 series turbofan engines. That AD currently requires replacing certain forward and aft centerbodies of the long fixed core exhaust nozzle (LFCEN) assembly. This AD adds certain new forward and aft centerbody part numbers (P/Ns) to the list requiring replacement. This AD was prompted by the discovery of more LFCEN forward and aft centerbody P/Ns that require replacement. We are issuing this AD to prevent the forward and aft centerbody of the LFCEN assembly from separating from the engine, causing damage to the engine, and damage to the airplane.

## The airworthiness directive

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by removing airworthiness directive (AD) 2009-04-17, Amendment 39-15823 (74 FR 8735; February 26, 2009), and adding the following new AD:

2011-07-01 General Electric Company: Amendment 39-16638; Docket No. FAA-2006-24145; Directorate Identifier 2006-NE-06-AD.

### (a) Effective Date

  (a) This airworthiness directive (AD) is effective April 22, 2011.

### (b) Affected ADs

  (b) This AD supersedes AD 2009-04-17, Amendment 39-15823.

### (c) Applicability

  (c) This AD applies to the following engines with a long fixed core exhaust nozzle (LFCEN) assembly forward centerbody, part number (P/N) 1313M55G01 or G02, P/N 9076M28G05, G06, G08, G09, or G10, P/N 9076M82G01 or G03, and aft centerbody P/N 1313M56G01, or P/N 9076M46G02, G04, or G05, installed in:

  (1) General Electric Company (GE) CF6-45A, CF6-45A2, CF6-50A, CF6-50C, CF6-50CA, CF6-50C1, CF6-50C2, CF6-50C2B, CF6-50C2D, CF6-50E, CF6-50E1, CF6-50E2, and CF6-50E2B turbofan engines, including engines marked on the engine data plate as CF6-50C2-F and CF6-50C2-R.

  (2) These engines are installed on, but not limited to, Airbus A300 series, Boeing 747-200B, 747-200C, 747-200F, 747-300 and 747SR, McDonnell Douglas DC-10-15, DC-10-30, DC-10-30F (KC-10A, KDC-10), and MD-10-30F airplanes.

### (d) Unsafe Condition

  (d) This AD was prompted by the discovery of more LFCEN forward and aft centerbody P/Ns that require replacement. We are issuing this AD to prevent the forward and aft centerbody of the LFCEN assembly from separating from the engine, causing damage to the engine, and damage to the airplane.

### (e) Compliance

  (e) Comply with this AD within the compliance times specified, unless already done.

  (1) Within 18 months after the effective date of this AD, replace forward centerbody, P/N 1313M55G01 and G02, P/N 9076M28G05, G06, G08, G09, and G10, P/N 9076M82G01 and G03, and aft centerbody P/N 1313M56G01, P/N 9076M46G02, G04, and G05 with a forward and aft centerbody that has been modified using the Accomplishment Instructions, Section 3, of GE Service Bulletin (SB) No. CF6-50 S/B 78-0244, Revision 1, dated March 13, 2008, CF6-50 S/B 78-0244, dated July 30, 2007, or CF6-50 S/B 78-0242, dated September 26, 2005.

### Centerbody Installation Prohibition

  (2) After 18 months from the effective date of this AD, do not install any engine with forward centerbody, P/N 1313M55G01 or G02, P/N 9076M28G05, G06, G08, G09, or G10, P/N 9076M82G01 or G03, or aft centerbody P/N 1313M56G01, P/N 9076M46G02, G04, or G05 on any airplane.

### (f) Alternative Methods of Compliance (AMOCs)

  (f) The Manager, Engine Certification Office, FAA, may approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

### (g) Related Information

  (g) For more information about this AD, contact Tomasz Rakowski, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate; phone: 781-238-7735; fax: 781-238-7199; e-mail: tomasz.rakowski@faa.gov.

  (h) For service information identified in this AD, contact GE-Aviation M/D Rm. 285, One Neumann Way, Cincinnati, OH 45215, telephone 513-552-3272; e-mail: geae.aoc@ge.com. You may review copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125.

## Rule preamble

### Dates

This AD is effective April 22, 2011.

### Addresses

For service information identified in this AD, contact GE-Aviation M/D Rm. 285, One Neumann Way, Cincinnati, OH 45215, telephone 513-552-3272; e-mail: geae.aoc@ge.com. You may review copies of the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125.

### For further information contact

Tomasz Rakowski, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate; phone: 781-238-7735; fax: 781-238-7199; e-mail: tomasz.rakowski@faa.gov.

### Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede airworthiness directive (AD) 2009-04-17, Amendment 39-15823 (74 FR 8735, February 26, 2009). That AD applies to the specified products. The NPRM published in the Federal Register on January 4, 2011 (76 FR 292). That NPRM proposed to add forward centerbody P/Ns 9076M28G05, G06, and G08, P/Ns 9076M82G01 and G03, and aft centerbody P/Ns 9076M46G02 and G04 to the P/Ns in AD 2009-04-17 that are required to be removed from service.

### Comments

We gave the public the opportunity to participate in developing this AD. The following presents the comment received on the proposal and the FAA's response to the comment.

### Request

One commenter, Boeing Commercial Airplanes, pointed out that the McDonnell Douglas airplanes affected by the proposed AD should be listed out as DC-10-15, DC-10-30, DC-10-30F, KC-10, KDC-10, and MD-10-30F. The commenter stated that the proposed AD only listed these airplanes as a series.

We agree. We revised this AD as requested, except we listed KC-10 as KC-10A as it appears in the Type Certificate Data Sheet.

### Conclusion

We reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting the AD with the change described previously.

### Costs of Compliance

We estimate that this AD will affect 383 GE CF6-45 and CF6-50 series turbofan engines installed on airplanes of U.S. registry. We also estimate that it will take about 44 work hours per engine to perform the actions required by this AD, and that the average labor rate is $85 per work-hour. Required parts will cost about $11,000 per engine. Based on these figures, we estimate the total cost of this AD to U.S. operators to be $5,645,420.

### Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

### Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that this AD:

  (1) Is not a “significant regulatory action” under Executive Order 12866,

  (2) Is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),

  (3) Will not affect intrastate aviation in Alaska, and

  (4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

### Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS E23EA](https://openairdocs.org/tcds/E23EA): General Electric Company; names 13 of 18 models: CF6-50E1, CF6-50CA, CF6-50A, CF6-50E, CF6-50C2D, CF6-50C1, CF6-50E2B, CF6-50C2…

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 21 (0 by airframe model, 21 by engine model)
- Makers: Mcdonnell Douglas 17, Mcdonnell-Douglas 2, Boeing 1, Bombardier 1

Models with the most aircraft:

- [GE CF6-50C2](https://openairdocs.org/engine/ge-cf6-50c2): 10 aircraft (engine model)
- [GE CF6-50 series](https://openairdocs.org/engine/ge-cf6-50-series): 9 aircraft (engine model)
- [GE CF6-45A2](https://openairdocs.org/engine/ge-cf6-45a2): 1 aircraft (engine model)
- [GE CF6-50C](https://openairdocs.org/engine/ge-cf6-50c): 1 aircraft (engine model)

All 4 models: https://openairdocs.org/ad/2011-07-01/models.md
Every aircraft: https://openairdocs.org/ad/2011-07-01/aircraft.md

## Related documents

- [AD 2009-04-17](https://openairdocs.org/ad/2009-04-17) (historical): Long fixed core exhaust nozzle (LFCEN) assembly · General Electric CF6-45A, CF6-45A2, CF6-50A and 10 more. Effective Apr 2, 2009. Replaced by this AD

No proposed rule in this release led to it. Its text cites no advisory circulars or STCs.

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