Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

[Federal Register Volume 77, Number 41 (Thursday, March 1, 2012)]
[Rules and Regulations]
[Pages 12448-12450]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-4745]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0944; Directorate Identifier 2011-NE-11-AD; 
Amendment 39-16960; AD 2012-04-04]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Division Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Pratt & Whitney PW4050, PW4052, PW4056, PW4060, PW4060A, PW4060C, 
PW4062, PW4062A, PW4152, PW4156, PW4156A, PW4158, PW4160, PW4460, 
PW4462, and PW4650 turbofan engines, including models with any dash 
number suffix. This AD was prompted by an engine overspeed event that 
occurred during taxi and resulted in a high-pressure compressor surge 
and tailpipe fire. This AD requires replacing Pratt & Whitney fuel 
metering units (FMUs), part numbers (P/Ns) 53T335 (HS 801000-1), 55T423 
(HS 801000-2), and 50U150 (HS 801000-3) at the next shop visit after 
the effective date of this AD. We are issuing this AD to prevent engine 
overspeed on these engines, which could result in an uncontained engine 
failure and damage to the airplane.

DATES: This AD is effective April 5, 2012.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of April 5, 
2012.

ADDRESSES: For service information identified in this AD, contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108, phone: 860-565-8770. 
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.

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, 12 New England Executive Park, Burlington, 
MA 01803; phone: 781-238-7742; fax: 781-238-7199; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM published in the Federal Register on November 7, 2011 (76 FR 
68660). That NPRM proposed to require replacing the FMU, P/N 50U150, at 
the next shop visit after the effective date of the proposed AD.

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 Specify the Replacement FMU

    Delta Airlines, Inc. requested that we specify replacing affected 
FMUs with FMU P/N 53U044, or later FAA-approved P/Ns. The commenter 
stated that doing this would help avoid potential alternative methods 
of compliance questions, and issues with specifying compliance to a 
service bulletin.
    We do not agree. We only identify the affected parts requiring 
removal in the AD, and the modification that is required to correct the 
design. If we identified the replacement part by P/N, then, if and when 
that part gets replaced by another P/N, the AD would have to be 
superseded. We did not change the AD.

Request To Extend the Compliance Time

    FedEx Express requested that we extend the compliance time from 60 
months from the issue date of the proposed AD. The additional time is 
needed to plan forced removals of the installed FMUs and implement an 
effective modification planning program.
    We do not agree. The compliance time specified in the AD is at the 
next shop visit. The commenter is referring to an outdated version of 
the service bulletin. We did not change the AD.

Request To Reference Hamilton Sundstrand Alert Service Bulletin (ASB) 
No. JFC131-2-73-A24

    Martinair Holland and United Airlines, Inc. requested that we also 
reference Hamilton Sundstrand ASB No. JFC131-2-73-A24, Revision 1, 
dated May 18, 2011, in the AD compliance, as that SB contains 
information required to perform the FMU modification required by the 
AD.
    We agree. We changed the AD to incorporate by reference (IBR) only 
that Hamilton Sundstrand ASB. That Hamilton Sundstrand ASB is also 
included within the Pratt & Whitney ASB No. PW4ENG A73-220, Revision 1, 
dated May 18, 2011, which we listed under Related Information.

Request To Add FMU Part Numbers

    Martinair Holland, United Airlines, Inc. and United Parcel Service 
Co. requested that we include Pratt & Whitney FMU P/Ns 53T335 and 
55T423 with the existing P/N 50U150, in the AD, and also include the 
equivalent Hamilton Sundstrand FMU P/Ns 801000-3, 801000-1, and 801000-
2.
    We agree and added those P/Ns to the AD. The equivalent Hamilton 
Sundstrand P/Ns are included in parentheses.

Request To Change Paragraph (f)

    United Airlines, Inc. requested that we change paragraph (f) from 
``install a modified FMU,'' to ``install a new or modified FMU.''
    We agree. The intent of the AD is to install an FMU incorporating 
the improvements of the modification, whether a new or modified FMU. We 
changed paragraph (f) in the AD.

Request To Not Incorporate by Reference the Alert SB

    United Airlines, Inc. requested that we not IBR Pratt & Whitney ASB 
No. PW4ENG A73-220, Revision 1, dated May 18, 2011, but to instead 
simply reference the ASB in the AD. The commenter stated that this 
would allow them flexibility to perform the FMU modification using 
their normal maintenance program and shop procedures.

[[Page 12449]]

    We partially agree. We agree to change the AD to not IBR Pratt & 
Whitney ASB No. PW4ENG A73-220, Revision 1, dated May 18, 2011. We do 
not agree with the AD having no procedure IBRed to support use of a 
normal maintenance program and shop procedures. We changed the AD to 
IBR the portion of the Hamilton Sundstrand ASB No. JFC131-2-73-A24, 
Revision 1, dated May 18, 2011, that contains the unique procedures 
required to modify the FMUs.

Comment About a Potential Shortage of Parts

    United Airlines, Inc. commented that a potential shortage of parts 
could affect compliance with the AD.
    We do not agree. Hamilton Sundstrand has worked to build up the FMU 
inventory to support the expected demand, so meeting the compliance 
time in the AD should not be a problem.

Request To Withdraw the Proposed AD

    United Parcel Service Co. requested that we withdraw the proposed 
AD. The commenter stated that since the overspeed incident occurred in 
2006, there were several maintenance actions initiated by Pratt & 
Whitney and implemented by operators to minimize the risk of further 
incidents. The actions include reducing the overhaul soft time in the 
maintenance planning guide for main fuel pumps, including in the engine 
manual additional inspections of the FMU servo wash filter and transfer 
fuel tubes, and clarifying the trouble shooting instructions in the 
aircraft fault isolation manual to identify symptoms of clogged servo 
wash filters.
    We do not agree. The unsafe condition exists in the design of the 
FMU, which must be addressed to prevent overspeed, potential 
uncontained engine failure, and damage to the airplane. The actions 
mentioned by the commenter were an interim plan to mitigate the risk of 
an unsafe condition. However, they do not represent the final 
corrective action. A servo wash filter clog followed by an overspeed 
event represents a single point failure in the engine design which can 
reasonably be expected to occur and which can result in a hazardous 
engine effect (uncontained engine failure). Because of this, the engine 
no longer meets the airworthiness standards to which it was certified. 
The intent of this AD action is to return the engine to the same level 
of safety provided by the airworthiness standards of its original 
certification. We did not withdraw the AD.

Request To Change the Compliance Time

    United Parcel Service Co. requested that we change the compliance 
time to the next component shop visit or at the next engine shop visit 
if the OEM recommended soft time is reached or exceeded. The commenter 
stated that operators with a low hour-to-cycle ratio would typically 
only overhaul the FMU at every other shop visit. The proposed AD 
compliance would require removal at the next shop visit, which could 
force removal of otherwise serviceable FMUs and add significant 
incremental labor and repair costs to operators.
    We do not agree. Performing the FMU replacement or modification at 
the next component shop visit interval would not provide an acceptable 
level of safety. We did not change the AD.

Request To Adjust the Cost of Compliance

    United Parcel Service Co. requested that we adjust the cost of 
compliance to include incremental costs for FMUs that will be forced 
out of service before reaching the recommended overhaul soft time of 
12,000 hours. The commenter states that the labor cost in the proposed 
AD assumes that the FMU is already in the shop and disassembled for 
normal FMU maintenance. It does not include labor hours that will be 
required for receiving inspection, disassembly, test, and preparation 
for shipment. The incremental cost of FMUs that are replaced before 
reaching its soft time are also not taken into account.
    We do not agree. FMUs can be modified to comply with the AD. They 
do not need to be replaced with a new FMU. The cost of the AD includes 
the required labor to perform the modification as well as the parts 
cost for the upgrade kit. We consider only the actual cost of the AD; 
not other costs. We did not change the AD.

Request To Replace FMUs On-Wing

    United Parcel Service Co. requested that we include in the AD the 
option to perform on-wing replacements of unmodified FMUs with new or 
modified FMUs. The commenter stated that the proposed AD only requires 
replacement at time of shop visit. Operators would then have to apply 
for an alternative method of compliance to replace an FMU on-wing.
    We partially agree. We agree that the operator could comply with 
the AD before the engine reaches the shop if the operator chooses to 
replace the FMU on-wing. We do not agree that a change to the AD is 
required because the operator can take credit for actions already done. 
Paragraph (e) of the AD states that you must comply with the AD within 
the compliance times specified, unless already done. We did not change 
the AD.

Request To Change the Installation Prohibition Paragraph

    United Parcel Service Co. requested that we change the installation 
prohibition paragraph (g) to prohibit installation of an unmodified FMU 
within the 3-year compliance period after a modified FMU has been 
installed. The commenter acknowledged that installation of an 
unmodified FMU is prohibited once a modified FMU is installed, but this 
is not explicitly stated in the proposed AD.
    We do not agree. Once you comply with the AD by installing a 
modified FMU in accordance with the AD at the next engine shop visit 
after the effective date of the AD, or elect to comply with the AD by 
installing a modified FMU before the next engine shop visit after the 
effective date of this AD, the engine is in compliance with the AD and 
you cannot undo that compliance. We did not change the AD.

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.

Costs of Compliance

    We estimate that this AD affects 750 engines installed on airplanes 
of U.S. registry. We also estimate that it will take about 3.2 work-
hours per product to comply with this AD. The average labor rate is $85 
per work-hour. Required parts will cost about $10,698 per engine. Based 
on these figures, we estimate the cost of the AD to U.S. operators to 
be $8,227,500.

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

[[Page 12450]]

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

    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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2012-04-04 Pratt & Whitney: Amendment 39-16960; Docket No. FAA-2011-
0944; Directorate Identifier 2011-NE-11-AD.

(a) Effective Date

    This AD is effective April 5, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney Division PW4050, PW4052, 
PW4056, PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4152, PW4156, 
PW4156A, PW4158, PW4160, PW4460, PW4462, and PW4650 turbofan 
engines, including models with any dash number suffix, with a Pratt 
& Whitney fuel metering unit (FMU) part number (P/N) 53T335 (HS 
801000-1), 55T423 (HS 801000-2), or 50U150 (HS 801000-3) installed.

(d) Unsafe Condition

    This AD was prompted by an engine overspeed event that occurred 
during taxi and resulted in a high-pressure compressor surge and 
tailpipe fire. We are issuing this AD to prevent engine overspeed on 
these engines, which could result in an uncontained engine failure 
and damage to the airplane.

(e) Compliance

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

(f) Replacement of Affected FMUs

    At the next shop visit after the effective date of this AD, 
remove FMU P/Ns 53T335 (HS 801000-1), 55T423 (HS 801000-2), and 
50U150 (HS 801000-3) and install an FMU that incorporates the 
modification in paragraphs 3.C through 3.E of the Accomplishment 
Instructions of Hamilton Sundstrand Alert Service Bulletin (ASB) No. 
JFC131-2-73-A24, Revision 1, dated May 18, 2011.

(g) Installation Prohibition

    After three years from the effective date of this AD, do not 
install or reinstall an FMU P/N 53T335 (HS 801000-1), 55T423 (HS 
801000-2), or 50U150 (HS 801000-3) onto any engine.

(h) Definition of Shop Visit

    For the purpose of this AD, a shop visit is when the engine is 
inducted into the shop for any maintenance involving the separation 
of pairs of major mating engine flanges (lettered flanges). However, 
the separation of engine flanges solely for the purposes of 
transporting the engine without subsequent engine maintenance is not 
an engine shop visit.

(i) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, has the authority 
to approve AMOCs for this AD, if requested using the procedures 
found in 14 CFR 39.19.

(j) Related Information

    (1) For more information about this AD, contact James Gray, 
Aerospace Engineer, Engine Certification Office, FAA, 12 New England 
Executive Park, Burlington, MA 01803; phone: 781-238-7742; fax: 781-
238-7199; email: [email protected].
    (2) Pratt & Whitney ASB No. PW4ENG A73-220, Revision 1, dated 
May 18, 2011, also pertains to this AD.

(k) Material Incorporated by Reference

    (1) You must use Hamilton Sundstrand Alert Service Bulletin No. 
JFC131-2-73-A24, Revision 1, dated May 18, 2011, to do the 
modifications required by this AD, unless the AD specifies 
otherwise. The Director of the Federal Register approved the 
incorporation by reference (IBR) under 5 U.S.C. 552(a) and 1 CFR 
part 51.
    (2) For service information identified in this AD, contact 
Hamilton Sundstrand, Technical Publications, Mail Stop 302-9, 4747 
Harrison Avenue, P.O. Box 7002, Rockford, Illinois 61125-7002; 
telephone 860-654-3575; fax 860-998-4564; email 
[email protected]; Internet http://www.hamiltonsundstrand.com, and Pratt & Whitney, 400 Main St. East 
Hartford, CT 06108, phone: 860-565-8770.
    (3) You may review copies of the 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.
    (4) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on February 15, 2012.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-4745 Filed 2-29-12; 8:45 am]
BILLING CODE 4910-13-P

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