
[Federal Register Volume 81, Number 207 (Wednesday, October 26, 2016)]
[Proposed Rules]
[Pages 74358-74360]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-25799]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-8836; Directorate Identifier 2016-NE-17-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Division Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
Pratt & Whitney Division (PW) PW4074, PW4074D, PW4077, PW4077D, PW4084, 
PW4084D, PW4090, and PW4090-3 turbofan engines. This proposed AD was 
prompted by an uncontained failure of a high-pressure turbine (HPT) hub 
during takeoff. This proposed AD would require an inspection to measure 
the surface condition of the aft side web/rim fillet of HPT 1st stage 
hubs and removal from service of hubs that fail inspection. We are 
proposing this AD to prevent failure of the HPT 1st stage hub, 
uncontained hub release, damage to the engine, and damage to the 
airplane.

DATES: We must receive comments on this proposed AD by December 12, 
2016.

[[Page 74359]]


ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, contact Pratt & 
Whitney Division, 400 Main St., East Hartford, CT 06118; phone: 800-
565-0140; fax: 860-565-5442. You may view this service information at 
the FAA, Engine & Propeller Directorate, 1200 District Avenue, 
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 by searching for and locating Docket No. FAA-2016-
8836; 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 proposed AD, the regulatory evaluation, any comments 
received, and other information. The street address for the Docket 
Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will 
be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Jo-Ann Theriault, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 1200 
District Avenue, Burlington, MA 01803; phone: 781-238-7105; fax: 781-
238-7199; email: jo-ann.theriault@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2016-8836; 
Directorate Identifier 2016-NE-07-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    We received a report of an uncontained failure of an HPT hub during 
takeoff. The root cause of the event is a machining anomaly (cutter 
mismatch) in the aft web/rim fillet area of the HPT 1st stage hub. The 
machining mismatch raises the stress and significantly reduces the life 
of the hub. The defect was introduced when the part was originally 
manufactured. This condition, if not corrected, could result in failure 
of the HPT 1st stage hub, uncontained hub release, damage to the 
engine, and damage to the airplane.

Related Service Information Under 1 CFR Part 51

    We reviewed PW Service Bulletin (SB) PW4G-112-72-342, dated 
September 23, 2016. This PW SB provides guidance on performing the HPT 
1st stage hub web/rim fillet replication inspection and measurement for 
the affected HPT hubs. This service information is reasonably available 
because the interested parties have access to it through their normal 
course of business or by the means identified in the ADDRESSES section.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require an inspection to measure the surface 
condition of the aft side web/rim fillet of HPT 1st stage hubs and 
removal from service of hubs that fail inspection.

Costs of Compliance

    We estimate that this proposed AD affects 119 engines installed on 
airplanes of U.S. registry. We also estimate that it would take about 1 
hour per engine to do the inspection. The average labor rate is $85 per 
hour. Based on these figures, we estimate the cost of this proposed AD 
on U.S. operators to be $10,115.

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 determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska to the extent 
that it justifies making a regulatory distinction, 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.

The Proposed Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

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


[[Page 74360]]


    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):

Pratt & Whitney Division: Docket No. FAA-2016-8836; Directorate 
Identifier 2016-NE-17-AD.

(a) Comments Due Date

    We must receive comments by December 12, 2016.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney Division (PW) PW4074, 
PW4074D, PW4077, PW4077D, PW4084, PW4084D, PW4090, and PW4090-3 
turbofan engines.

(d) Unsafe Condition

    This AD was prompted by an uncontained failure of a high-
pressure turbine (HPT) hub during takeoff. We are issuing this AD to 
prevent failure of the HPT 1st stage hub, uncontained hub release, 
damage to the engine, and damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) At the next engine shop visit after the effective date of 
this AD, perform the HPT 1st stage hub web/rim fillet replication 
inspection and measurement using the Accomplishment Instructions, 
Part A, paragraphs 2.A. and 2.B.(1) to 2.B.(4) or Part B, paragraphs 
1.A. and 1.B.(1) to 1.B.(4), of PW Service Bulletin (SB) PW4G-112-
72-342, dated September 23, 2016.
    (2) If the hub fails inspection, remove the hub from service 
before further flight and replace with a part eligible for 
installation.

(f) Definition

    For the purpose of this AD, an ``engine shop visit'' is the 
induction of an engine into the shop for maintenance involving the 
separation of any major mating flange, except that the separation of 
engine flanges solely for the purposes of transportation without 
subsequent maintenance does not constitute an engine shop visit.

(g) Installation Prohibition

    After the effective date of this AD, do not install or re-
install into any engine any HPT 1st stage hub that has not been 
inspected and passed the inspection required by paragraph (e) of 
this AD.

(h) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, may approve AMOCs 
for this AD. Use the procedures found in 14 CFR 39.19 to make your 
request. You may email your request to: ANE-AD-AMOC@faa.gov.

(i) Related Information

    (1) For more information about this AD, contact Jo-Ann 
Theriault, Aerospace Engineer, Engine Certification Office, FAA, 
Engine & Propeller Directorate, 1200 District Avenue, Burlington, MA 
01803; phone: 781-238-7105; fax: 781-238-7199; email: jo-ann.theriault@faa.gov.
    (2) PW SB PW4G-112-72-342, dated September 23, 2016, can be 
obtained from PW using the contact information in paragraph (i)(3) 
of this AD.
    (3) For service information identified in this AD, contact Pratt 
& Whitney Division, 400 Main St., East Hartford, CT 06118; phone: 
800-565-0140; fax: 860-565-5442.
    (4) You may view this service information at the FAA, Engine & 
Propeller Directorate, 1200 District Avenue, Burlington, MA. For 
information on the availability of this material at the FAA, call 
781-238-7125.


    Issued in Burlington, Massachusetts, on October 19, 2016.
Colleen M. D'Alessandro,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-25799 Filed 10-25-16; 8:45 am]
 BILLING CODE 4910-13-P


