AD 2018-02-10

Recurring final rule

Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

AD Number: 2018-02-10
Status: final_rule
Effective Date: February 26, 2018
Product Category: aircraft
Docket: Docket No. FAA-2017-0719
FR Citation: 83 FR 2896

Applicability

Type	Manufacturer	Model	Details
engine	Pratt & Whitney	Division	Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

Unsafe Condition

multiple cracked outer diffuser cases

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

initial and repetitive inspections to detect cracks in the outer diffuser case and removal from service of cases that fail inspection

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

within 1,000 flight cycles from the effective date of this AD

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

PW PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan engines

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

We are adopting a new airworthiness directive (AD) for all Pratt & Whitney Division (PW) PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan engines. This AD was prompted by the discovery of multiple cracked outer diffuser cases. This AD requires initial and repetitive inspections to detect cracks in the outer diffuser case and removal from service of cases that fail inspection. We are issuing this AD to address the unsafe condition on these products.

Applicability Source Text

Show captured applicability text from the source AD

(c) Applicability

    This AD applies to all Pratt & Whitney Division (PW) PW4074, 
PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan 
engines with outer diffuser case, part number (P/N) 50J775 or P/N 
50J930, installed.

Document Text

Show stored source text (verify against official source)

[Federal Register Volume 83, Number 14 (Monday, January 22, 2018)]
[Rules and Regulations]
[Pages 2896-2899]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2018-00999]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0719; Product Identifier 2017-NE-22-AD; Amendment
39-19163; AD 2018-02-10]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Division Turbofan
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: We are adopting a new airworthiness directive (AD) for all
Pratt & Whitney Division (PW) PW4074, PW4074D, PW4077, PW4077D,
PW4084D, PW4090, and PW4090-3 turbofan engines. This AD was prompted by
the discovery of multiple cracked outer diffuser cases. This AD
requires initial and repetitive inspections to detect cracks in the
outer diffuser case and removal from service of cases that fail
inspection. We are issuing this AD to address the unsafe condition on
these products.

DATES: This AD is effective February 26, 2018.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of February 26,
2018.

ADDRESSES: For service information identified in this final rule,
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. For information on the
availability of this material at the FAA, call 781-238-7759. It is also
available on the internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a> by searching
for and locating Docket No. FAA-2017-0719.

Examining the AD Docket

You may examine the AD docket on the internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a> by searching for and locating Docket No. FAA-2017-
0719; 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 final rule, the regulatory evaluation, any comments received, and
other information. The address for Docket Operations (phone: 800-647-
5527) is Document Operations, U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor,

[[Page 2897]]

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

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: <a href="/cdn-cgi/l/email-protection#660c094b07080848120e03140f07130a122600070748010910">[email&#160;protected]</a>.

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 by adding an AD that would apply to PW PW4074, PW4074D, PW4077,
PW4077D, PW4084D, PW4090, and PW4090-3 turbofan engines. The NPRM
published in the Federal Register on August 25, 2017 (82 FR 40514). The
NPRM was prompted by the discovery of multiple cracked outer diffuser
cases. The NPRM proposed to require initial and repetitive inspections
to detect cracks in the outer diffuser case and removal from service of
cases that fail inspection. We are issuing this AD to correct the
unsafe condition on these products.

Comments

We gave the public the opportunity to participate in developing
this final rule. The following presents the comments received on the
NPRM and the FAA's response to each comment.

Request To Change Compliance

PW requested that we change the effective date of the 1,000 cycle
drawdown to ``within 1,000 flight cycles from March 31, 2017'', to
coincide with PW Alert Service Bulletin (ASB) PW4G-112-A72-347, rather
than ``within 1,000 flight cycles from the effective date of this AD''.
PW stated that making the 1,000 cycle drawdown effective March 31,
2017, rather than the effective date of this AD, maintains the same
level of risk.
We disagree with changing the effective date of the 1,000 cycle
drawdown to ``within 1,000 flight cycles from March 31, 2017'', to
coincide with PW ASB PW4G-112-A72-347 because we cannot force mandatory
action based on dates in the past. Mandatory action must be based on
the effective date of this AD. In addition, we determined that basing
the initial inspection and the inspection interval on the effective
date of this AD maintains an acceptable level of safety. We did not
change this AD.

Request To Add Credit for Previous Actions

PW and United Airlines (UAL) requested that we add Credit for
Previous Actions to allow operators to take credit for inspections
performed per PW ASB PW4G-112-A72-347, dated March 31, 2017 prior to
the effective date of this AD.
We disagree. Since use of PW ASB PW4G-112-A72-347, dated March 31,
2017, is required in the compliance section of this AD, we do not need
to reference this SB in the Credit for Previous Actions paragraph.
Inspections performed per PW ASB PW4G-112-A72-347 prior to the
effective date of this AD meet the criteria of ``unless already done''
in the compliance section of this AD.

Request To Change Definitions

UAL requested that we define ``engine disassembly'' as ``when the M
flange is split''. UAL reasoned that this would clarify the compliance
requirements for operators and is consistent with PW ASB PW4G-112-A72-
347, dated March 31, 2017.
We agree. Defining ``engine disassembly'' clarifies compliance
requirements for operators. We added a Definition paragraph to this AD.

Request To Change Compliance Time

UAL requested that we add a third option for the initial inspection
so that it could be performed prior to accumulating 13,000 cycles since
new, or within 1,000 cycles from the effective date of this AD, or
within 2,000 cycles since the last outer diffuser case piece-part
fluorescent penetration inspection (FPI), whichever occurs later.
We partially agree. We agree with giving operator's credit for
inspections done at piece-part exposure because if the outer diffuser
case was inspected at piece-part exposure and passed inspection, it
meets the initial inspection requirement mandated by this AD. We added
a ``Credit for Previous Actions'' paragraph to this AD. Therefore, we
disagree with adding the third option to the initial inspection
compliance time specified in paragraph (g)(1) of this AD.

Request To Change Compliance

UAL requested that we identify the outer diffuser case piece-part
level FPI done in accordance with PW Cleaning, Inspection and Repair
(CIR) Manual 72-41-13, Inspection/Check-02, as an acceptable means of
compliance for the repetitive inspections. UAL reasoned that when the
outer diffuser case is at piece-part level, PW CIR Manual 72-41-13,
Inspection/Check-02, is performed. The piece-part level FPI is
equivalent to the high sensitivity module level inspection provided in
PW ASB PW4G-112-A72-347, dated March 31, 2017.
We agree. Inspections performed at piece-part exposure maintain an
acceptable level of safety because the piece-part level FPI specified
in PW CIR Manual Part Number 51A750, section 72-41-13, Inspection/
Check-02 is equivalent to the inspection mandated by this AD. Since we
did not incorporate by reference a particular FPI process
specification, a high sensitivity FPI using the methods, techniques,
and practices equivalent to the current manufacturer's maintenance
manual or Instructions for Continued Airworthiness satisfy both the
initial and repetitive requirements of this AD. We did not change this
AD.

Request To Change Service Information

PW requested that we change the service information reference from
PW ASB PW4G-112-A72-347, dated March 31, 2017, to PW ASB PW4G-112-A72-
347, Revision No. 1, dated October 26, 2017. PW stated that the SB has
been revised to provide inspection clarifications requested by
operators.
We disagree. We did not include PW ASB PW4G-112-A72-347, Revision
No. 1, dated October 26, 2017, since the risk analysis was based on the
original ASB and we did not have the opportunity to give the public a
chance to comment on this revision. We did not change this AD.

Conclusion

We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
this final rule with the changes described previously. We have
determined that these minor changes:
<bullet> Are consistent with the intent that was proposed in the
NPRM for correcting the unsafe condition; and
<bullet> 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 this final
rule.

Related Service Information Under 1 CFR Part 51

We reviewed PW ASB PW4G-112-A72-347, dated March 31, 2017. This PW
ASB provides guidance on performing outer diffuser case FPIs. 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.

Other Related Service Information

We reviewed PW4000 Series (112 Inch) Engine CIR Manual, Part Number
51A750, Revision Number 74, section

[[Page 2898]]

72-41-13, Inspection/Check-02, dated July 15, 2017. This manual section
provides guidance on performing a high sensitivity FPI of the outer
diffuser case at piece-part exposure.

Costs of Compliance

We estimate that this AD affects 121 engines installed on airplanes
of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
Tt3 boss inspection................... 3.5 work-hours x $85 per $0 $297.50 $35,997.50
hour = $297.50.
----------------------------------------------------------------------------------------------------------------

We estimate the following costs to do any necessary replacements
that would be required based on the results of the proposed inspection.
We estimate six cases will need to be replaced in the domestic fleet.

On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product
----------------------------------------------------------------------------------------------------------------
FPI Inspection of outer diffuser case...... 10 work-hours x $85 per hour = $850 $0 $850
Replacement of outer diffuser case......... $0................................. 750,000 750,000
----------------------------------------------------------------------------------------------------------------

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

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):

2018-02-10 Pratt & Whitney Division: Amendment 39-19163; Docket No.
FAA-2017-0719; Product Identifier 2017-NE-22-AD.

(a) Effective Date

This AD is effective February 26, 2018.

(b) Affected ADs

None.

This AD applies to all Pratt & Whitney Division (PW) PW4074,
PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan
engines with outer diffuser case, part number (P/N) 50J775 or P/N
50J930, installed.

(d) Subject

Joint Aircraft System Component (JASC) Code 7240, Turbine Engine
Combustion Section.

(e) Unsafe Condition

This AD was prompted by the discovery of multiple cracked outer
diffuser cases. We are issuing this AD to prevent failure of the
outer diffuser case. The unsafe condition, if not corrected, could
result in failure of the outer diffuser case, uncontained case
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) Perform an initial high sensitivity fluorescent penetrant
inspection (FPI) of the outer diffuser case T3 thermocouple probe
boss (Tt3 boss) prior to accumulating 13,000 cycles since new (CSN),
or within 1,000 flight cycles from the effective date of this AD,
whichever occurs later. If the case CSN is unknown, inspect within
1,000 flight cycles from the effective date of this AD.

[[Page 2899]]

(2) Thereafter, repeat the high sensitivity FPI of the outer
diffuser case Tt3 boss within 2,000 flight cycles since the last
FPI.
(3) If an indication is found during the inspections required by
paragraphs (g)(1) or (2) of this AD, re-inspect or remove the outer
diffuser case from service as follows:
(i) For engines installed on-wing, re-inspect or remove in
accordance with the Accomplishment Instructions, Part A, paragraph
1.G., of PW ASB PW4G-112-A72-347, dated March 31, 2017.
(ii) For assembled engines not installed on-wing, re-inspect or
remove in accordance with the Accomplishment Instructions, Part B,
paragraph 1.C., of PW ASB PW4G-112-A72-347, dated March 31, 2017.
(iii) For disassembled engines, if any cracks are found, remove
the outer diffuser case from service before further flight.
(4) Within 30 days of the effective date of this AD, update the
mandatory inspections of the Airworthiness Limitations Section (ALS)
of your Instructions for Continued Airworthiness to include the
piece-part inspections of the diffuser case as defined in Figure 1
to paragraph (g) of this AD.
[GRAPHIC] [TIFF OMITTED] TR22JA18.001

(h) Credit for Previous Actions

You may take credit for the high sensitivity FPI of the outer
diffuser case Tt3 boss that is required by paragraph (g)(1) of this
AD if you performed a high sensitivity FPI of the outer diffuser
case at piece-part exposure before the effective date of this AD,
using PW4000 Series (112 Inch) Engine CIR Manual, P/N 51A750,
section 72-41-13, Inspection/Check-02, dated July 15, 2017.

(i) Definition

For the purpose of this AD, an engine is considered disassembled
any time the ``M'' flange is separated.

(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
ECO Branch, send it to the attention of the person identified in
paragraph (k)(1) of this AD. You may email your request to: <a href="/cdn-cgi/l/email-protection#0d4c4348204c49204c40424e4d6b6c6c236a627b">[email&#160;protected]</a>.
(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: <a href="/cdn-cgi/l/email-protection#dbb1b4f6bab5b5f5afb3bea9b2baaeb7af9bbdbabaf5bcb4ad">[email&#160;protected]</a>.
(2) PW4000 Series (112 Inch) Engine CIR Manual, Part Number
51A750, Revision Number 74, section 72-41-13, Inspection/Check-02,
dated July 15, 2017, which is not incorporated by reference in this
AD, can be obtained from PW, using the contact information in
paragraph (l)(3) of this AD.

(l) Material Incorporated by Reference

(1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the service information listed
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
(i) Pratt & Whitney (PW) Alert Service Bulletin PW4G-112-A72-
347, dated March 31, 2017.
(ii) Reserved.
(3) For PW 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 FAA, Engine and
Propeller Standards Branch, 1200 District Avenue, Burlington, MA.
For information on the availability of this material at the FAA,
call 781-238-7759.
(5) You may view this 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: <a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">http://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.

Issued in Burlington, Massachusetts, on January 12, 2018.
Robert J. Ganley,
Manager, Engine and Propeller Standards Branch, Aircraft Certification
Service.
[FR Doc. 2018-00999 Filed 1-19-18; 8:45 am]
BILLING CODE 4910-13-P

Source: Official FAA Source ↗

Retrieved: Apr 4, 2026

Rights: U.S. Government Public Domain

This site is not affiliated with or endorsed by the FAA. Always verify with official sources.

View Official Source ↗ Find More ADs for Pratt & Whitney Division

Airworthiness Directives; Pratt & Whitney Division Turbofan Engines

Applicability

Unsafe Condition

Required Actions

Compliance Time

Affected Aircraft

Federal Register Abstract

Applicability Source Text

Document Text

Related Airworthiness Directives

2021-05-16 Recurring

2021-05-51

2017-12-03

2016-22-05 Recurring