DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-1116; Product Identifier 2016-NE-32-AD; Amendment
39-19459; AD 2018-21-01]
RIN 2120-AA64

Airworthiness Directives; Honeywell International Inc. Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are superseding Airworthiness Directive (AD) 2017-20-06 for
certain Honeywell International Inc. (Honeywell) AS907-1-1A turbofan
engines. AD 2017-20-06 required a one-time inspection of the second
stage low-pressure turbine (LPT2) blades and, if the blades fail the
inspection, the replacement of the blades with a part eligible for
installation. This AD continues to require a one-time inspection of the
LPT2 blades and, if the blades fail the inspection, the replacement of
the blades with a part eligible for installation. This AD was prompted
by the need to clarify the Applicability and Compliance sections of AD
2017-20-06. We are issuing this AD to address the unsafe condition on
these products.

DATES: This AD is effective November 19, 2018.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of November 9,
2017 (82 FR 46379, October 5, 2017).

ADDRESSES: For service information identified in this final rule,
contact Honeywell International Inc., 111 S 34th Street, Phoenix, AZ
85034-2802; phone: 800-601-3099; internet: https://myaerospace2.
honeywell.com/wps/portal. 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. It is also
available on the internet at http://www.regulations.gov by searching
for and locating Docket No. FAA-2017-1116.

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-2017-
1116; 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 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: Joseph Costa, Aerospace Engineer, Los
Angeles ACO Branch, FAA, 3960 Paramount Blvd., Lakewood, CA 90712-4137;
phone: 562-627-5246; fax: 562-627-5210; email: joseph.costa@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to supersede AD 2017-20-06, Amendment 39-19063 (82 FR 46379,
October 5, 2017), (``AD 2017-20-06''). AD 2017-20-06 applied to certain
Honeywell International Inc. (Honeywell) AS907-1-1A turbofan engines.
The NPRM published in the Federal Register on January 30, 2018 (83 FR
4167). The NPRM was prompted by the need to clarify the Applicability
and Compliance sections of AD 2017-20-06. The NPRM proposed to continue
to require one-time inspection of the LPT2 blades and, if the blades
fail the inspection, the replacement of the blades with a part eligible
for installation. We are issuing this AD to address the unsafe
condition on these products.

Comments

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

Request To Align the Compliance Requirements With the Service Bulletin
(SB)

Bombardier Aerospace (Bombardier) requested that the compliance
requirements of the AD be aligned with Honeywell SB AS907-72-9067,
Revision 1, dated March 20, 2017. Bombardier asked that we remove the
requirements for measured wear requirements for recording of wear.
Bombardier noted that Honeywell SB AS907-72-9067 requires contact
between the LPT2 rotor blade Z-gap.
We disagree. Honeywell SB AS907-72-9067, Revision 1, dated March
20, 2017 and the compliance section of this AD provide the same
guidance for measuring and recording wear with a borescope at the LPT2
blade shroud Z-gap. Reported borescope inspections of high-time engines
show that blade-to-blade contact at the Z-gap is difficult to measure
with a borescope. The FAA and Honeywell agree that the measured wear
limit of 0.005'', as defined by the Honeywell Light Maintenance Manual
(LMM) AS907-1-1A, 72-00-00, is acceptable for this AD.
Additionally, the FAA disagrees with the request to remove the
requirement for recordings of the borescope inspection. We find that
making these recordings with a clean digital image helps us to identify
wear characteristics, severity, and cumulative damage of LPT2 blade
assembly and to provide future borescope requirements for LPT blade
maintenance. We did not change this AD.

Request To Revise Costs of Compliance

Bombardier Aerospace requested that we align the cost estimates in
this AD with the cost estimates in Honeywell's SB.
We disagree. The slight differences in costs between the NPRM and
Honeywell's SB reflect the additional recording requirements in this
AD. We did not change this AD.

Revision to Applicability

The intent of the NPRM was to limit the applicability of this AD to
affected blades that have more than 8,000 hours since new on November
9, 2017 (the effective date of AD 2017-20-06). We therefore revised the
applicability to refer to ``November 9, 2017,'' instead of ``the
effective date of this AD.''

Conclusion

We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
this AD as proposed.

Related Service Information Under 1 CFR Part 51

We reviewed Honeywell SB AS907-72-9067, Revision 1, dated March 20,
2017. This SB describes procedures for inspecting the LPT2 blades. 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 Honeywell SB AS907-72-9067, Revision 0, dated December
12, 2016, which also describes procedures for inspecting the LPT2
blades. We also reviewed the Honeywell LMM AS907-1-1A, 72-00-00,
Section 72-05-12, dated May 25, 2016, and Section 72-55-03, dated
September 27, 2011, which provide additional guidance for performing
borescope inspections.

Costs of Compliance

We estimate that this AD affects 40 engines installed on airplanes
of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs

We estimate the following costs to do any necessary replacements
that would be required based on the results of the inspection. We
estimate that 40 engines will need this replacement.

On-Condition Costs

Paperwork Reduction Act

A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a currently valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to be
approximately 1 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, completing and reviewing the collection of
information. All responses to this collection of information are
mandatory. Send comments regarding this burden estimate or any other
aspect of this collection of information, including suggestions for
reducing this burden to: Information Collection Clearance Officer,
Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX
76177-1524.

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 have determined that 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

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]

2. The FAA amends Sec. 39.13 by removing Airworthiness Directive (AD)
2017-20-06, Amendment 39-19063 (82 FR 46379, October 5, 2017), and
adding the following new AD: