Document ID: FAA-2018-0826-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Pratt and Whitney Division (PW) Turbofan Engines
Posted Date: 2018-10-10T04:00Z

[Federal Register Volume 83, Number 196 (Wednesday, October 10, 2018)]
[Proposed Rules]
[Pages 50862-50864]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-21694]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0826; Product Identifier 2018-NE-27-AD]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Division (PW) 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 
certain Pratt & Whitney Division (PW) PW4074, PW4074D, PW4077, PW4077D, 
PW4084D, PW4090, and PW4090-3 turbofan engines. This proposed AD was 
prompted by an in-flight failure of a 1st stage low-pressure compressor 
(LPC) blade. This proposed AD would require initial and repetitive 
thermal acoustic imaging (TAI) inspections for cracks in certain 1st 
stage LPC blades and removal of those blades that fail inspection. We 
are proposing this AD to address the unsafe condition on these 
products.

DATES: We must receive comments on this proposed AD by November 26, 
2018.

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 and Propeller Standards Branch, 1200 District Avenue, 
Burlington, MA 01803. For information on the availability of this 
material at the FAA, call 781-238-7759.

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-2018-
0826; or in person at Docket Operations between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays. The AD docket contains 
this NPRM, the regulatory evaluation, any comments received, and other 
information. The street address for Docket Operations (phone: 800-647-
5527) is listed above. Comments will be available in the AD docket 
shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Jo-Ann Theriault, Aerospace Engineer, 
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 
781-238-7105; fax: 781-238-7199; email: [email protected].

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-2018-0826; 
Product Identifier 2018-NE-27-AD'' at the beginning of your comments. 
We specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this NPRM. We will consider all 
comments received by the closing

[[Page 50863]]

date and may amend this NPRM 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 NPRM.

Discussion

    We learned of an uncontained 1st stage LPC blade failure and inlet 
separation on a PW4000-112 series turbofan engine that occurred during 
a revenue flight. The fracture in the blade initiated from a low cycle 
fatigue crack in the airfoil. This blade failure was contained by the 
engine case, but there was subsequent uncontained forward release of 
the inlet cowl, causing damage to the aircraft and prompting an 
emergency descent. This condition, if not addressed, could result in an 
uncontained failure of a 1st stage LPC blade, damage to the engine, and 
damage to the airplane.

Related Service Information Under 1 CFR Part 51

    We reviewed PW Alert Service Bulletin (ASB) PW4G-112-A72-268, 
Revision No. 7, dated September 6, 2018. This PW ASB describes 
procedures for performing 1st stage LPC blade TAI inspections. 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 initial and repetitive TAI 
inspections of 1st stage LPC blades and removal of blades that fail 
inspection.

Costs of Compliance

    We estimate that this proposed AD affects 120 engines installed on 
airplanes of U.S. registry. We estimate the following costs to comply 
with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Inspection............................  22 work-hours x $85 per               $0          $1,870        $224,400
                                         hour = $1,870.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the proposed inspection. 
We have no way of determining the number of aircraft that might need 
these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace 1st stage LPC blade...................  0 work-hours x $85 per hour = $0        $125,000        $125,000
----------------------------------------------------------------------------------------------------------------

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.
    This AD is issued in accordance with authority delegated by the 
Executive Director, Aircraft Certification Service, as authorized by 
FAA Order 8000.51C. In accordance with that order, issuance of ADs is 
normally a function of the Compliance and Airworthiness Division, but 
during this transition period, the Executive Director has delegated the 
authority to issue ADs applicable to engines, propellers, and 
associated appliances to the Manager, Engine and Propeller Standards 
Branch, Policy and Innovation Division.

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, 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:

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

[[Page 50864]]

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-2018-0826; Product 
Identifier 2018-NE-27-AD.

(a) Comments Due Date

    We must receive comments by November 26, 2018.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney Division (PW) PW4074, 
PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan 
engines, with 1st stage low-pressure compressor (LPC) blade, part 
numbers 52A241, 55A801, 55A801-001, 55A901, 55A901-001, 56A201, 
56A201-001, or 56A221, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section.

(e) Unsafe Condition

    This AD was prompted by an uncontained 1st stage LPC blade 
failure. We are issuing this AD to prevent failure of the 1st stage 
LPC blade. The unsafe condition, if not addressed, could result in 
uncontained blade release, damage to the engine, and damage to the 
airplane.

(f) Compliance

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

(g) Required Actions

    (1) After the effective date of this AD, perform an initial 
Thermal Acoustic Imaging (TAI) inspection of the 1st stage LPC 
blades as follows:
    (i) For 1st stage LPC blades that have accumulated fewer than 
6,500 cycles since new (CSN), perform a TAI inspection the next time 
the engine is separated at the M-flange, or prior to the 1st stage 
LPC blade accumulating 7,000 CSN, whichever occurs first.
    (ii) For 1st stage LPC blades that have accumulated 6,500 or 
more CSN, or if the cycles since the blade was new cannot be 
determined, or if the cycles since the blade was last TAI inspected 
cannot be determined, perform a TAI inspection within 500 flight 
cycles or 180 days from the effective date of this AD, whichever 
occurs first.
    (2) Thereafter, perform a TAI inspection of 1st stage LPC blades 
every time the engine is separated at the M-flange and the blades 
have accumulated 1,000 or more flight cycles since the last TAI 
inspection, not to exceed 6,500 flight cycles since the last TAI 
inspection.
    (3) If any 1st stage LPC blade fails the inspection required by 
paragraph (g)(1) or (2) of this AD, remove the blade from service 
and replace with a part eligible for installation before further 
flight.
    (4) The TAI inspection and disposition required for compliance 
with this AD must be accomplished by a method approved by the FAA. 
You can find a vendor that has an FAA-approved TAI inspection listed 
in the Vendor Services Section of PW Alert Service Bulletin (ASB) 
PW4G-112-A72-268, Revision No. 7, dated September 6, 2018.

(h) Credit for Previous Actions

    You may take credit for the initial TAI inspection required by 
paragraph (g)(1) of this AD if you performed the TAI inspection 
before the effective date of this AD using PW ASB PW4G-112-A72-268, 
Revision No. 6, dated August 5, 2014.

(i) Installation Prohibition

    Do not install any 1st stage LPC blade that has accumulated 
1,000 or more flight cycles into any engine unless it has passed the 
inspection required by paragraph (g)(1) of this AD.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, ECO Branch, FAA, has the authority to approve 
AMOCs for this AD, if requested using the procedures found in 14 CFR 
39.19. In accordance with 14 CFR 39.19, send your request to your 
principal inspector or local Flight Standards District Office, as 
appropriate. If sending information directly to the manager of the 
certification office, send it to the attention of the person 
identified in paragraph (k) of this AD. You may email your request 
to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(k) Related Information

    (1) For more information about this AD, contact Jo-Ann 
Theriault, Aerospace Engineer, ECO Branch, FAA, 1200 District 
Avenue, Burlington, MA, 01803; phone: 781-238-7105; fax: 781-238-
7199; email: [email protected].
    (2) 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. You may view this referenced 
service information at the FAA, Engine & Propeller Standards Branch, 
1200 District Avenue, Burlington, MA, 01803. For information on the 
availability of this material at the FAA, call 781-238-7759.

    Issued in Burlington, Massachusetts, on September 28, 2018.
Robert J. Ganley,
Manager, Engine and Propeller Standards Branch, Aircraft Certification 
Service.
[FR Doc. 2018-21694 Filed 10-9-18; 8:45 am]
 BILLING CODE 4910-13-P