[Federal Register Volume 89, Number 224 (Wednesday, November 20, 2024)]
[Rules and Regulations]
[Pages 91539-91541]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-27041]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 33
[Docket No. FAA-2024-2164; Special Conditions No. 33-025-SC]
Special Conditions: Pratt and Whitney Canada Model PW220A Engine;
30-Minute All Engine Operating Power Rating
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for the Pratt and Whitney
Canada (P&WC) Model PW220A engine. This engine will have a novel or
unusual design feature when compared to the state of technology
envisioned in the airworthiness standards for aircraft engines. This
design feature is a 30-minute all engine operating (AEO) power rating.
This rating will be used for hovering at increased power for search and
rescue missions. The applicable airworthiness regulations do not
contain adequate or appropriate safety standards for this design
feature. These special conditions contain the additional safety
standards that the Administrator considers necessary to establish a
level of safety equivalent to that established by the existing
airworthiness standards.
DATES: This action is effective on P&WC on November 20, 2024. Send
comments on or before January 6, 2025.
ADDRESSES: Send comments identified by Docket No. FAA-2024-2164 using
any of the following methods:
Federal eRegulations Portal: Go to www.regulations.gov and
follow the online instructions for sending your comments
electronically.
Mail: Send comments to Docket Operations, M-30, U.S.
Department of Transportation (DOT), 1200 New Jersey Avenue SE, Room
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
Hand Delivery or Courier: Take comments to Docket
Operations in Room W12-140 of the West Building Ground Floor at 1200
New Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
Fax: Fax comments to Docket Operations at 202-493-2251.
Docket: Background documents or comments received may be read at
www.regulations.gov at any time. Follow the online instructions for
accessing the docket or go to Docket Operations in Room W12-140 of the
West Building Ground Floor at 1200 New Jersey Avenue SE, Washington,
DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays.
FOR FURTHER INFORMATION CONTACT: Alberto Hernandez, Engine and
Propulsion Section, AIR-625, Technical Policy Branch, Policy and
Standards Division, Aircraft Certification Service, Federal Aviation
Administration, 107 Charles W. Grant Parkway, Atlanta, GA 30354;
telephone (781) 238-7329; email [email protected].
SUPPLEMENTARY INFORMATION: The substance of these special conditions
has been published in the Federal Register for public comment in
several prior instances with no substantive comments received.
Therefore, the FAA finds, pursuant to title 14, Code of Federal
Regulations (14 CFR) 11.38(b), that new comments are unlikely, and
notice and comment prior to this publication are unnecessary.
Privacy
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in Sec.
11.35, the FAA will post all comments received without change to
www.regulations.gov, including any personal information you provide.
The FAA will also post a report summarizing each substantive verbal
contact received about these special conditions.
Confidential Business Information
Confidential Business Information (CBI) is commercial or financial
information that is both customarily and actually treated as private by
its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552),
CBI is exempt from public disclosure. If your comments responsive to
these special conditions contain commercial or financial information
that is customarily treated as private, that you actually treat as
private, and that is relevant or responsive to these special
conditions, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and the indicated comments will not be
placed in the public docket of these special conditions. Send
submissions containing CBI to the individual listed in the For Further
Information Contact section above. Comments the FAA receives, which are
not specifically designated as CBI, will be placed in the
[[Page 91540]]
public docket for these special conditions.
Comments Invited
The FAA invites interested people to take part in this rulemaking
by sending written comments, data, or views. The most helpful comments
reference a specific portion of the special conditions, explain the
reason for any recommended change, and include supporting data.
The FAA will consider all comments received by the closing date for
comments. The FAA may change these special conditions based on the
comments received.
Background
On November 16, 2021, P&WC applied for a type certificate for its
new Model PW220A engine. The Model PW220A engine is a new centerline
free-turbine turboshaft engine design intended to be used on transport
category twin-engine helicopters. The engine architecture is a split
compression system that incorporates the latest generation design
methodology of a high-pressure ratio compressor, providing significant
improvements in specific fuel consumption (SFC) and power.
A single low pressure compressor (LPC) is driven by a two-stage
uncooled power turbine, which also provides mechanical power through an
output shaft to the helicopter rotor system. The high pressure
compressor (HPC) is a two-stage compressor system driven by a single-
stage cooled high pressure turbine (HPT).
Type Certification Basis
Under the provisions of 14 CFR 21.17, P&WC must show that the Model
PW220A engine meets the applicable provisions of part 33, dated
February 1, 1965, as amended by amendments 33-1 through 33-34.
If the Administrator finds that the applicable airworthiness
regulations (e.g., 14 CFR part 33) do not contain adequate or
appropriate safety standards for the P&WC Model PW220A engine because
of a novel or unusual design feature, special conditions are prescribed
under the provisions of Sec. 21.16.
Special conditions are initially applicable to the model for which
they are issued. Should the type certificate for that model be amended
later to include any other model that incorporates the same novel or
unusual design feature, these special conditions would also apply to
the other model under Sec. 21.101.
The FAA issues special conditions, as defined in Sec. 11.19, in
accordance with Sec. 11.38, and they become part of the type
certification basis under Sec. 21.17(a)(2).
Novel or Unusual Design Feature
The P&WC Model PW220A engine will incorporate the following novel
or unusual design feature:
A 30-minute all engine operating (AEO) power rating.
Discussion
The type certification basis for the Model PW220A engine does not
contain adequate or appropriate airworthiness standards to address a
30-minute AEO power rating. Therefore, special conditions are necessary
to provide additional requirements for rating definition, instructions
for continued airworthiness (ICA), and endurance testing.
The 30-minute time limit applies to each instance the rating is
used; however, there is no limit to the number of times the rating can
be used during any one flight, and there is no cumulative time
limitation. The ICA requirement in these special conditions is intended
to address the unknown nature of actual usage of the 30-minute AEO
power rating and any associated engine deterioration. The applicant is
expected to make an assessment of the expected usage and publish ICA's
and airworthiness limitations section (ALS) limits in accordance with
those assumptions, such that engine deterioration is not excessive. The
endurance test requirement of 25 hours of operation at a 30-minute AEO
rating is similar to several special conditions issued over the past 20
years addressing the same subject. Because the PWC Model PW220A
turboshaft engine has a continuous one engine inoperative (OEI) rating
and limits equal to or higher than the 30-minute AEO rating, the test
time performed at the continuous OEI rating may be credited toward the
25-hour requirement. However, test time spent at other rating elements
of the Sec. 33.87 endurance test, such as takeoff or other OEI ratings
(that may be equal to or higher values), may not be counted toward the
25 hours of required running. These special conditions contain the
additional safety standards that the Administrator considers necessary
to establish a level of safety equivalent to that established by the
existing airworthiness standards.
Applicability
As discussed above, these special conditions are applicable to the
P&WC Model PW220A engine. Should PW&C apply at a later date for a
change to the type certificate to include another model incorporating
the same novel or unusual design feature, these special conditions
would apply to that model as well.
Conclusion
This action affects only a certain novel or unusual design feature
on one engine model. It is not a rule of general applicability.
List of Subjects in 14 CFR Part 33
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
Authority Citation
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702, and
44704.
The Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for the Pratt and Whitney Canada Model
PW220A engine.
In addition to the general definitions in 14 CFR 1.1, the following
definition applies to these special conditions: ``Rated 30-Minute All
Engine Operating (AEO) Power,'' means the approved shaft horsepower
developed under static conditions at the specified altitude and
temperature, and within the operating limitations established under
part 33, and limited in use to periods not exceeding 30-minutes each.
In addition to the airworthiness standards in part 33, the
following special conditions apply:
(a) Sections 33.1 Applicability and 33.3 General: As applicable,
all documentation, testing, and analysis required to comply with the
part 33 certification basis, must account for the 30-minute AEO rating,
limits, and usage.
(b) Section 33.4, Instructions for Continued Airworthiness (ICA).
In addition to the requirements of Sec. 33.4, the ICA must:
(1) Include instructions to ensure that in-service engine
deterioration due to rated 30-minute AEO power usage will not be
excessive, meaning that all other approved ratings are available within
associated limits and assumed usage, for successive flights; and that
deterioration will not exceed that assumed for declaring a time between
overhaul (TBO) period.
(i) The applicant must validate the adequacy of the maintenance
actions required under paragraph (b)(1) above.
[[Page 91541]]
(2) Include in the airworthiness limitations section (ALS), any
mandatory inspections and serviceability limits related to the use of
the 30-minute AEO rating.
(c) Section 33.87, Endurance Test. In addition to the requirements
of Sec. Sec. 33.87(a) and 33.87(d), the overall test run must include
a minimum of 25 hours of operation at 30-minute AEO power and limits,
divided into periods of 30-minutes AEO power with alternate periods at
maximum continuous power or less.
(1) Modification of the Sec. 33.87 test requirements to include
the 25 hours of operation at 30-minute AEO power rating must be
proposed by the Applicant and accepted by the FAA.
(2) Each Sec. 33.87(d) continuous one-engine-inoperative (OEI)
rating test period of 30-minutes or longer, run at power and limits
equal to or higher than the 30-minutes AEO rating, may be credited
toward this requirement. Note that the test time required for the
takeoff or other OEI ratings may not be counted toward the 25 hours of
operation required at the 30-minute AEO rating.
Issued in Seattle, Washington, on November 13, 2024.
Paul R. Siegmund,
Acting Manager, Technical Policy Branch, Policy and Standards Division,
Aircraft Certification Service.
[FR Doc. 2024-27041 Filed 11-19-24; 8:45 am]
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