AD 2010-24-09

AD Final Rules - 2010-24-09.pdf
Copy URL
Document Versions
 Feedback
DetailsAttachments/Public Comments
AD Number:
2010-24-09
Document Type:
AD Final Rules
Docket Number:
FAA-2010-0725
Subject Heading:
Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines
Subject:
No. 3 bearing oil pressure tubes
Status:
Current
Citation:
Federal Register: November 23, 2010 (Volume 75, Number 225)
Citation Publish Date:
11/23/2010
Effective Date:
12/28/2010
Make:
Pratt & Whitney Division
Model:
PW4050 | PW4052 | PW4056 | PW4060 | PW4060A | PW4060C | PW4062 | PW4062A ...Show more
Product Type:
Engine
Product Subtype:
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
Automatic Zoom
Actual Size
Page Fit
Page Width
⁨50⁩%
⁨75⁩%
⁨100⁩%
⁨125⁩%
⁨150⁩%
⁨200⁩%
⁨300⁩%
⁨400⁩%
125%
of ⁨5⁩
[Federal Register: November 23, 2010 (Volume 75, Number 225)]


[Rules and Regulations]


[Page 71351-71353]


From the Federal Register Online via GPO Access [wais.access.gpo.gov]


[DOCID:fr23no10-4]


––––––––––––––––––––––––––––––––––


DEPARTMENT OF TRANSPORTATION


Federal Aviation Administration


14 CFR Part 39


[Docket No. FAA-2010-0725; Directorate Identifier 2010-NE-18-AD]; Amendment 39-16528;


AD 2010-24-09]


RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines


AGENCY:
 
Federal Aviation Administration (FAA), DOT.


ACTION:
 
Final rule.


––––––––––––––––––––––––––––––––––


SUMMARY:
 
We are adopting a new airworthiness directive (AD) for the products listed above. This


AD requires a one-time visual inspection of the No. 3 bearing oil pressure tube, part number (P/N)


51J041-01, P/N 50J604-01, or P/N 50J924-01. Tubes that are found cracked or repaired must be


removed from service. This AD also prohibits repaired tubes from being installed. This AD results


from one report of a repaired No. 3 bearing oil tube that caused an engine in-flight shutdown, seven


reports of repaired No. 3 bearing oil pressure tubes found cracked that led to unscheduled engine


removals, and one report of a test cell event from a repaired tube that cracked. We are issuing this AD


to prevent cracking of No. 3 bearing oil pressure tubes, which could result in internal oil fire, failure


of the high-pressure turbine (HPT) disks, uncontained engine failure, and damage to the airplane.


DATES:
 
This AD is effective December 28, 2010.


Examining the AD Docket


You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at


the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal


holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and


other information. The address for the Docket Office (phone: 800-647-5527) is Document


Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building


Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.


FOR FURTHER INFORMATION CONTACT:
 
James Gray, Aerospace Engineer, Engine


Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park,


Burlington, MA 01803; telephone (781) 238-7742; fax (781) 238-7199; e-mail:


james.e.gray@faa.gov.


1
SUPPLEMENTARY INFORMATION:


Discussion


We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an


airworthiness directive (AD) that would apply to the specified products. That NPRM published in the


Federal Register on June 3, 2010 (75 FR 31330). That NPRM proposed to require:


•
 
A one-time visual inspection of the No. 3 bearing oil pressure tube, P/N 51J041-01, P/N


50J604-01, or P/N 50J924-01; and


•
 
Removal from service if found cracked or repaired, or if suspected that the tube was repaired;


and


•
 
A prohibition on installing repaired tubes.


Comments


We gave the public the opportunity to participate in developing this AD. The following presents


the comments received on the proposal and the FAA's response to each comment.


Request To Clarify Paragraph (e) of the Proposed AD


United Airlines asked us to revise paragraph (e) of the proposed AD to inspect the tube when the


tube is in the piece-part condition. United Airlines felt that changing paragraph (e) of the proposed


AD will make our intent clear.


We agree. We revised paragraph (e) of the proposed AD to say ''You are responsible for having


the actions required by this AD performed the next time the No. 3 bearing oil pressure tube is in the


piece-part condition after the effective date of this AD, unless the actions have already been done.''


We also added a new heading ''Definitions'' and new paragraph (i) that defines piece-part condition


for the oil pressure tube.


Request To Provide Clarification of the Definition of a Repair


Delta Airlines, Inc. and United Airlines asked us to clarify the types of repaired tubes that must


be removed. Delta Airlines Inc. and United Airlines said the body of the NPRM states that weld


repairs were the source of the failures.


We don't agree. All repairs are unacceptable, not just weld repairs. Further, the original


equipment manufacturer also revised their applicable repair manual(s) to remove all repairs to these


tubes.


Conclusion


We reviewed the relevant data, considered the comments received, and determined that air safety


and the public interest require adopting the AD with the changes described previously and minor


editorial changes. We have determined that these minor changes:


•
 
Are consistent with the intent that was proposed in the NPRM for correcting the unsafe


condition; and


•
 
Do not add any additional burden upon the public than was already proposed in the NPRM.


We also determined that these changes will not increase the economic burden on any operator or


increase the scope of the AD.


2