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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2019-1021; Project Identifier MCAI-2019-00120-E;
Amendment 39-21166; AD 2020-15-03]
RIN 2120-AA64
Airworthiness Directives; GE Aviation Czech s.r.o. Turboprop
Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2016-07-13
and AD 2018-03-22 which apply to certain GE Aviation Czech s.r.o.
M601D-11, M601E-11, M601E-11A, M601E-11AS, M601E-11S, and M601F model
turboprop engines. AD 2016-07-13 required inspection of the engine
power turbine (PT) disk and, if found damaged, its replacement with a
part eligible for installation. AD 2018-03-22 required the removal of
certain engine PT disks identified by part number (P/N) installed on
the affected engines. This AD requires an inspection of the engine PT
disk and, if found damaged, its replacement with a part eligible for
installation. This AD also requires the removal of certain engine PT
disks identified by P/N installed on the affected engines. This AD was
prompted by the discovery of damage to certain engine PT disks and a
review by the manufacturer that determined that certain engine PT
rotors have less overspeed margin than originally declared during
product certification. This AD was also prompted by the manufacturer
identifying additional P/Ns and serial numbers (S/Ns) of engine PT
disks affected by damage or non-conformity since publishing AD 2016-07-
13 and AD 2018-03-22. The FAA is issuing this AD to address the unsafe
condition on these products.
DATES: This AD is effective August 31, 2020.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 31, 2020.
ADDRESSES: For service information identified in this final rule,
contact GE Aviation Czech s.r.o., Beranovych 65, 199 02 Praha
9--Letnany, Czech Republic; phone: +420 222 538 111; fax +420
222 538 222; email: tp.ops@ge.com. You may view this service
information at the FAA, Airworthiness Products Section, Operational
Safety 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 https://www.regulations.gov by
searching for and locating Docket No. FAA-2019-1021.
Examining the AD Docket
You may examine the AD docket on the internet at https://www.regulations.gov by
searching for and locating Docket No. FAA-2019-
1021; 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 mandatory continuing airworthiness information
(MCAI), any comments received, and other information. The address for
Docket Operations 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: Mehdi Lamnyi, Aerospace Engineer, ECO
Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-
238-7743; fax: 781-238-7199; email: Mehdi.Lamnyi@faa.gov.
SUPPLEMENTARY INFORMATION:
Discussion
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2016-07-13, Amendment 39-18458 (81 FR
20222, April 7, 2016) ("AD 2016-07-13"), and AD 2018-03-22, Amendment
39-19195 (83 FR 6455, February 14, 2018) ("AD 2018-03-22"). AD 2016-
07-13 and AD 2018-03-22 applied to certain GE Aviation Czech s.r.o.
M601D-11, M601E-11, M601E-11A, M601E-11AS, M601E-11S, and M601F model
turboprop engines. The NPRM published in the Federal Register on
February 21, 2020 (85 FR 10099). The NPRM was prompted by the discovery
of damage to certain engine PT disks and a review by the manufacturer
that determined that certain engine PT rotors have less overspeed
margin than originally declared during product certification. The NPRM
was also prompted by the manufacturer
identifying additional P/Ns and S/Ns of engine PT disks affected by
damage or non-conformity since publishing AD 2016-07-13 and AD 2018-03-
22. The NPRM proposed to require an inspection of the engine PT disk
and, if found damaged, its replacement with a part eligible for
installation. The NPRM also proposed to require the removal of certain
engine PT disks identified by P/N installed on the affected engines.
The FAA is issuing this AD to address the unsafe condition on these
products.
The European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Community, has
issued EASA AD 2019-0143, dated June 13, 2019 (referred to after this
as "the MCAI"), to address the unsafe condition on these products.
The MCAI states:
During engine shop visits or overhauls, certain PT discs may
have been damaged in the area of the balance weights. Additional PT
discs with non-conforming geometry of the slot radius may also have
been released to service as a result of incorrect machining of the
PT disc slot.
This condition, if not detected and corrected, could lead to PT
disc failure, with subsequent release of high-energy debris,
possibly resulting in damage to, and/or reduced control of, the
aeroplane.
After [EASA] ADs [2016-0025-E and 2017-0100] were issued, GEAC
identified additional P/N and s/n of PT discs affected by damage or
non-conformity. For those, as well as for the PT discs affected by
the reduction of the declared theoretical PT rotor overspeed limit,
an update of the risk assessment was performed, and GEAC issued the
original issue of the ASB, later revised, providing applicable
instructions.
Consequently, EASA issued AD 2019-0061, retaining the
requirements of EASA AD 2016-0025-E and EASA AD 2017-0100, which
were superseded, and requiring a one-time inspection and, depending
on findings, replacement of certain PT discs identified by P/N and
s/n. That [EASA] AD also required replacement of certain PT discs
identified by P/N, and prohibited (re)installation of affected
parts.
Since that [EASA] AD was issued, it has been determined that the
compliance time for replacement of affected part on Group 2 engines
has to be amended, and GEAC published the ASB (now at Revision 02).
For the reason stated above, this [EASA] AD retains the
requirements of EASA AD 2019-0061, which is superseded, introducing
amended compliance times for Group 2 engines.
You may obtain further information by examining the MCAI in the AD
docket on the internet at https://www.regulations.gov by searching for
and locating Docket No. FAA-2019-1021.
Comments
The FAA gave the public the opportunity to participate in
developing this final rule. The FAA received no comments on the NPRM or
on the determination of the cost to the public.
Conclusion
The FAA reviewed the relevant data and determined that air safety
and the public interest require adopting this AD as proposed except for
minor editorial changes. The FAA has determined that these minor
changes.
Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.
Related Service Information Under 1 CFR Part 51
The FAA reviewed GE Aviation Alert Service Bulletin (ASB) ASB-
M601E-72-50-00-0069[02], ASB-M601D-72-50-00-0052[02], ASB-M601T-72-50-
00-0028[02], ASB-M601F-72-50-00-0035[02], and ASB-M601Z-72-50-00-
0038[02] (single document; formatted as service bulletin
identifier[revision number]), dated June 11, 2019. The ASB provides
procedures for replacing the engine PT disk. 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.
Costs of Compliance
The FAA estimates that this AD affects 24 GE Aviation Czech s.r.o.
M601 turboprop engines installed on airplanes of U.S. registry. The FAA
estimates that 12 affected turboprop engines are "Group 1" engines
and 12 are "Group 2" engines.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
|
ACTION
|
LABOR COST
|
PARTS COST
|
COST PER
PRODUCT
|
COST ON U.S.
OPERATORS
|
| Inspect the engine PT disk (Group 1 engines). |
52 work-hours x $85 perhour = $4,420. |
$0
|
$4,420
|
$53,040
|
| Replace the engine PT disk (Group 2 and 3 engines). |
56 work-hours x $85 per hour = $4,760. |
6,989
|
11,749
|
140,988
|
The FAA estimates the following costs to do any necessary
replacements that would be required based on the results of the
required inspections. The FAA has no way of determining the number of
engines that might need this replacement:
On-Condition Costs
|
ACTION
|
LABOR COST
|
PARTS COST
|
COST PER
PRODUCT
|
| Replace the engine PT disk (Group 1 engines) |
8 work-hours x $85 per hour = $680. |
$6,989
|
$7,669
|
g to the manufacturer, some of the costs of this AD may be
covered under warranty, thereby reducing the cost impact on affected
individuals. The FAA does not control warranty coverage for affected
individuals. As a result, the FAA has included all costs in its cost
estimate.
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.
The FAA is 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
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 this AD:
(1) Is not a "significant regulatory action" under Executive Order 12866,
(2) Will not affect intrastate aviation in Alaska, and
(3) 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:
a. Removing Airworthiness Directive (AD) 2016-07-13, Amendment 39-18458
(81 FR 20222, April 7, 2016), and AD 2018-03-22, Amendment 39-19195 (83
FR 6455, February 14, 2018); and
b. Adding the following new AD:
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