Document ID: FAA-2019-0618-0001
Agency: faa
Document Type: Rule
Title: Special Conditions: Pilatus Aircraft Ltd., Model PC-12/47E Airplanes; Electronic Engine Control System Installation
Posted Date: 2019-08-15T04:00Z

[Federal Register Volume 84, Number 158 (Thursday, August 15, 2019)]
[Rules and Regulations]
[Pages 41595-41597]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-17571]

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 Rules and Regulations
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  Federal Register / Vol. 84, No. 158 / Thursday, August 15, 2019 / 
Rules and Regulations  

[[Page 41595]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. FAA-2019-0618; Special Conditions No. 23-295-SC]

Special Conditions: Pilatus Aircraft Ltd., Model PC-12/47E 
Airplanes; Electronic Engine Control System Installation

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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

SUMMARY: These special conditions are issued for the Pilatus Aircraft 
Ltd., Model PC-12/47E airplane. This airplane will have a novel or 
unusual design feature associated with installation of an engine that 
includes an electronic engine control system. 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: The effective date of these special conditions is August 15, 
2019.
    The FAA must receive your comments by September 16, 2019.

ADDRESSES: Send comments identified by docket number FAA-2019-0618 
using any of the following methods:
    [squ] Federal eRegulations Portal: Go to http://www.regulations.gov 
and follow the online instructions for sending your comments 
electronically.
    [squ] 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.
    [squ] Hand Delivery of 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.
    [squ] Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: The FAA will post all comments it receives, without 
change, to http://regulations.gov, including any personal information 
the commenter provides. Using the search function of the docket 
website, anyone can find and read the electronic form of all comments 
received into any FAA docket, including the name of the individual 
sending the comment (or signing the comment for an association, 
business, labor union, etc.). DOT's complete Privacy Act Statement can 
be found in the Federal Register published on April 11, 2000 (65 FR 
19477-19478).
    Docket: Background documents or comments received may be read at 
http://www.regulations.gov at any time. Follow the online instructions 
for accessing the docket or go to the 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: Jeff Pretz, AIR-691, Small Airplane 
Standards Branch, Policy & Innovation Division, Aircraft Certification 
Service, Federal Aviation Administration, 901 Locust, Room 301, Kansas 
City, MO 64106; telephone (816) 329-3239; facsimile (816) 329-4090.

SUPPLEMENTARY INFORMATION: 

Reason for No Prior Notice and Comment Before Adoption

    The FAA has determined, in accordance with 5 U.S. Code Sec. Sec.  
553(b)(3)(B) and 553(d)(3), that notice and opportunity for prior 
public comment hereon are unnecessary because substantially identical 
special conditions have been subject to the public comment process in 
several prior instances such that the FAA is satisfied that new 
comments are unlikely. For the same reason, the FAA finds that good 
cause exists for making these special conditions effective upon 
issuance. The FAA is requesting comments to allow interested persons to 
submit views that may not have been submitted in response to the prior 
opportunities for comment.

------------------------------------------------------------------------
        Special conditions No.               Company/airplane model
------------------------------------------------------------------------
23-253-SC \1\........................  Diamond Aircraft Industries/Model
                                        DA-40NG.
23-267-SC \2\........................  Cirrus Design Corporation/Model
                                        SF50.
23-282-SC \3\........................  Pilatus Aircraft Ltd./Model PC-
                                        24.
23-292-SC \4\........................  Costruzioni Aeronautiche Tecnam
                                        S.P.A./Model P2012.
------------------------------------------------------------------------

Comments Invited
---------------------------------------------------------------------------

    \1\ http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSC.nsf/0/1A102658468C62D386257950004D7183?OpenDocument.
    \2\ https://www.govinfo.gov/app/details/FR-2015-09-23/2015-24156/summary.
    \3\ https://www.govinfo.gov/app/details/FR-2017-07-17/2017-14936.
    \4\ https://www.federalregister.gov/documents/2019/04/26/2019-08476/special-conditions-costruzioni-aeronautiche-tecnam-spa-model-p2012-airplane-electronic-engine.
---------------------------------------------------------------------------

    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 
asks that you send two copies of written comments.
    The FAA will consider all comments received on or before the 
closing date for comments. The FAA will consider comments filed late if 
it is possible to do so without incurring expense or delay. The FAA may 
change these special conditions based on the comments received.

Background

    On March 9, 2017, Pilatus Aircraft Ltd. (Pilatus) applied for FAA 
validation of its change to Type Certificate No. A78EU \5\ for 
installation of an electronic engine control (EEC) system--commonly 
referred to as a full authority digital engine control (FADEC)--in the 
Model PC-12/47E airplane. The Model PC-12/47E is a normal category, 
metallic, pressurized, low-wing, monoplane that seats nine passengers 
and two flightcrew. A single Pratt & Whitney PT6E-67XP \6\ engine 
driving a

[[Page 41596]]

five bladed variable pitch constant speed Hartzell propeller powers the 
airplane. The airplane has retractable tricycle landing gear, a 
Honeywell Primus APEX avionics suite, and a maximum takeoff weight of 
10,450 pounds.
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    \5\ See http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/019EED2BA802A848862583360061A683?OpenDocument&Highlight=a78eu.
    \6\ As of this special condition publishing date, engine 
approval is in process. The final engine model number will be 
updated on Type Certification Data Sheet A78EU upon engine approval 
completion.
---------------------------------------------------------------------------

    The Model PC-12/47E is equipped with a single Pratt & Whitney PT6E-
67XP that uses an EEC system instead of a traditional mechanical 
control system. Although the EEC is certificated with the engine, the 
installation of an EEC requires evaluation due to critical 
environmental effects and possible effects on or by other airplane 
systems such as indirect effects of lightning, radio interference with 
other airplane electronic systems, and shared engine, airplane data, 
and power sources.
    Sections 23.1306, 23.1308, and 23.1309 contain requirements for 
evaluating the installation of complex systems, including electronic 
systems and critical environmental effects. However, the use of EECs 
for engines was not envisioned when Sec.  23.1309 was published. The 
integral nature of these systems makes it necessary to ensure proper 
evaluation of the airplane functions, which may be included in the EEC, 
and that the installation does not degrade the EEC reliability approved 
under part 33 during engine type certification. Sections 23.1306(a) and 
23.1308(a) apply to the EEC to ensure it remains equivalent to a 
mechanical only system, which is not generally susceptible to the High 
Intensity Radiated Fields (HIRF) and lightning environments.
    In some cases, the airplane in which the engine is installed 
determines a higher classification than the engine controls are 
certificated for, requiring the EEC systems be analyzed at a higher 
classification. As of November 2005, EEC special conditions mandated 
the Sec.  23.1309 classification for loss of EEC control as 
catastrophic for any airplane. This is not to imply an engine failure 
is classified as catastrophic, but that the EEC must provide an 
equivalent reliability to mechanical engine controls. In addition, 
Sec. Sec.  23.1141(e) and 25.901(b)(2) provide the fault tolerant 
design requirements of turbine engine mechanical controls to the EEC 
and ensure adequate inspection and maintenance intervals for the EEC.
    Part 23 did not envision the use of full authority EECs and lacks 
the specific regulatory requirements necessary to provide an adequate 
level of safety. Therefore, special conditions are necessary.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Pilatus must show that the 
Model PC-12/47E airplane, as changed, continues to meet the applicable 
provisions of the regulations incorporated by reference in Type 
Certificate No. A78EU or the applicable regulations in effect on the 
date of application for the change. The regulations incorporated by 
reference in the type certificate are commonly referred to as the 
``original type certification basis.'' In addition to the original type 
certification basis, the FAA has determined that the Model PC-12/47E 
must also comply with Sec.  23. 905(d) as amended by amendment 23-59, 
Sec.  23.1306 as amended by amendment 23-61, Sec.  23.1308 as amended 
by amendment 23-57, and Sec. Sec.  23.1309 and 23.1310 as amended by 
amendment 23-62.
    If the Administrator finds that the applicable airworthiness 
regulations in part 23 do not contain adequate or appropriate safety 
standards for the Model PC-12/47E airplane because of a novel or 
unusual design feature, special conditions are prescribed under the 
provisions of Sec.  21.16.
    The FAA issues special conditions, as defined in Sec.  11.19, under 
Sec.  11.38 and they become part of the type certification basis under 
Sec.  21.101.
    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, or should any other model already included on 
the same type certificate be modified to incorporate the same novel or 
unusual design feature, the FAA would apply these special conditions to 
the other model.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model PC-12/47E must comply with the fuel vent and 
exhaust emission requirements of 14 CFR part 34 and the noise 
certification requirements of 14 CFR part 36; and the FAA must issue a 
finding of regulatory adequacy under Sec.  611 of Public Law 92-574, 
the ``Noise Control Act of 1972.''

Novel or Unusual Design Features

    The Model PC-12/47E airplane will incorporate the following novel 
or unusual design features:
    The installation of an EEC system, which is the generic family of 
electrical/electronic engine control systems to include full authority 
digital engine controls, supervisory controls, and derivatives of these 
controls.

Discussion

    This airplane makes use of an electronic engine control system 
instead of a traditional mechanical control system, which is a novel 
design for this type of airplane. The applicable airworthiness 
regulations do not contain adequate or appropriate safety standards for 
this design feature. Mandating a structured assessment to determine 
potential installation issues mitigate concerns that the addition of an 
electronic engine control does not produce a failure condition not 
previously considered.

Applicability

    These special conditions are applicable to the Model PC-12/47E 
airplane. Should Pilatus apply at a later date for a change to the type 
certificate to include another model incorporating the same novel or 
unusual design feature, the FAA would apply these special conditions to 
that model as well.

Conclusion

    This action affects only a certain novel or unusual design feature 
on the Model PC-12/47E airplane. It is not a rule of general 
applicability.

List of Subjects in 14 CFR Part 23

    Aircraft, Aviation safety, Signs and symbols.

Citation

    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701-44702; Pub. L. 
113-53, 127 Stat. 584 (49 U.S.C. 44704) note.

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 Pilatus Aircraft Ltd. Model PC-12/47E 
airplanes.

Installation of Electronic Engine Control System

    (a) For electronic engine control (EEC) system installations, it 
must be established that no single failure or malfunction or probable 
combinations of failures of EEC system components will have an effect 
on the system, as installed in the airplane, that causes the Loss of 
Power Control (LOPC) probability of the system to exceed those allowed 
in part 33 certification.
    (b) Electronic engine control system installations must be 
evaluated for environmental and atmospheric conditions, including 
lightning and High Intensity Radiated Fields (HIRF). The EEC system 
lightning and HIRF

[[Page 41597]]

effects that result in LOPC should be considered catastrophic.
    (c) The components of the installation must be constructed, 
arranged, and installed to ensure their continued safe operation 
between normal inspections or overhauls.
    (d) Functions incorporated into any electronic engine control that 
make it part of any equipment, systems or installation whose functions 
are beyond that of basic engine control, and which may also introduce 
system failures and malfunctions, are not exempt from Sec.  23.1309 and 
must be shown to meet part 23 levels of safety as derived from Sec.  
23.1309. Part 33 certification data, if applicable, may be used to show 
compliance with any part 23 requirements. If part 33 data is used to 
substantiate compliance with part 23 requirements, then the part 23 
applicant must be able to provide this data for its showing of 
compliance.

    Note:  The term ``probable'' in the context of ``probable 
combination of failures'' does not have the same meaning as used for 
a safety assessment process. The term ``probable'' in ``probable 
combination of failures'' means ``foreseeable,'' or those failure 
conditions anticipated to occur one or more times during the 
operational life of each airplane.

    Issued in Kansas City, Missouri, on August 9, 2019.
Pat Mullen,
Manager, Small Airplane Standards Branch, Policy and Innovation 
Division, Aircraft Certification Service.
[FR Doc. 2019-17571 Filed 8-14-19; 8:45 am]
BILLING CODE 4910-13-P