[Federal Register Volume 83, Number 43 (Monday, March 5, 2018)]
[Rules and Regulations]
[Pages 9176-9178]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-04417]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. FAA-2018-0090; Special Conditions No. 23-286-SC]


Special Conditions: Textron Aviation, Inc., Model C90A King Air; 
Installation of Electronic Engine Control System

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 Textron Aviation, 
Inc., model C90A King Air airplane. This airplane as modified by 
Nextant Aerospace 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 March 5, 2018.
    We must receive your comments by April 4, 2018.

ADDRESSES: Send comments identified by docket number FAA-2018-0090 
using any of the following methods:
     Federal eRegulations Portal: Go to http://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 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.
     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), as well as at http://DocketsInfo.dot.gov.
    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, Federal Aviation 
Administration, Aircraft Certification Service, Policy & Innovation 
Division, Small Airplane Standards Branch, AIR-691, 901 Locust, Room 
301, Kansas City, MO 64106; telephone (816) 329-3239; facsimile (816) 
329-4090.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice and 
opportunity for prior public comment hereon are impracticable because 
these procedures would significantly delay issuance of the approval 
design and thus delivery of the affected aircraft. In addition, the FAA 
has determined, in accordance with 5 U.S.C. 553(b)(3)(B) and 553(d)(3), 
that notice and opportunity for prior public comment hereon are 
unnecessary because the substance of these special conditions has been 
subject to the public comment process in several prior instances with

[[Page 9177]]

no substantive comments received. The FAA therefore finds that good 
cause exists for making these special conditions effective upon 
issuance.

------------------------------------------------------------------------
        Special conditions No.               Company/airplane model
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23-01-05-SC \1\.......................  Eclipse Aviation Corporation/
                                         Model 500.
23-10-03-SC \2\.......................  Diamond Aircraft Industries/
                                         Model DA-40NG.
23-98-03-SC \3\.......................  Raytheon Aircraft Company/Model
                                         3000.
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Comments Invited
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    \1\ http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSC.nsf/0/3B5A8ECF0327533486256B80006AEF68?OpenDocument&Highlight=23-01-05-sc.
    \2\ http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSC.nsf/0/4D1C0F368222693386257904004BC13F?OpenDocument&Highlight=electronic%20engine%20control.
    \3\ http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgSC.nsf/0/FF5633DA88FBF46586256B96005F8AAF?OpenDocument&Highlight=electronic%20engine%20control.
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    We invite 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. We ask 
that you send us two copies of written comments.
    We will consider all comments we receive on or before the closing 
date for comments. We will consider comments filed late if it is 
possible to do so without incurring expense or delay. We may change 
these special conditions based on the comments we receive.

Background

    On January 12, 2016, Nextant Aerospace applied for a supplemental 
type certificate (STC) for installation of two General Electric (GE) 
H75-100E engines that include electronic engine and propeller controls 
in the model C90A King Air. The model C90A, currently approved under 
Type Certificate No. 3A20, is a normal category twin turbo-propeller 
airplane with a maximum capacity of up to 13 passengers and a maximum 
takeoff weight of up to 9650 lbs. or 10,100 lbs., depending on the 
serial number modified. The airplane includes two Pratt & Whitney 
Corporation (PWC) PT6A-21 engines and either Hartzell or McCauley 
reversing propellers.
    Nextant Aerospace originally received an STC for the model C90A for 
installation of two GE H75-100 engines. Nextant Aerospace has made 
application to amend the STC to install GE H75-100E engines, which 
include single channel analog supervisory electronic engine controls 
(EECs) in addition to the existing mechanical engine controls. The EEC 
does not include any software, but does provide single lever control 
for both the fuel metering and propeller control. The EEC also ensures 
the engine and propeller remain within their operating limits 
throughout the approved operating range, including propeller reverse 
operation and starting. Loss of the EEC results in the pilot control of 
the hydro-mechanical metering/shut-off lever.
    The Nextant Aerospace installation of GE H75-100E engines in the 
model C90A King Air use an electronic engine control system (a single 
channel supervisory control with a mechanical backup as opposed to a 
two-channel full authority control with no mechanical backup) instead 
of a traditional mechanical only control system. Although the engine 
control system is certificated as part of the engine, the installation 
of an engine with an electronic control system requires evaluation due 
to critical environmental effects and possible effects on or by other 
airplane systems. This includes indirect effects of lightning, radio 
interference with other airplane electronic systems, shared engine and 
airplane data, and power sources.
    The regulatory requirements in 14 CFR part 23 for evaluating the 
installation of complex systems, including electronic systems and 
critical environmental effects, are contained in Sec. Sec.  23.1306, 
23.1308, and 23.1309. However, when Sec.  23.1309 was developed, the 
use of electronic control systems for engines was not envisioned. The 
integral nature of these systems makes it necessary to ensure the 
airplane functions, which may be included in the EEC, are properly 
evaluated and that the installation does not degrade the EEC 
reliability, which is approved under part 33. Sections 23.1306(a) and 
23.1308(a) are applied 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) are applied to provide the fault 
tolerant design requirements of turbine engine mechanical controls to 
the EEC and ensure adequate inspection and maintenance interval for the 
EEC. As this is a supervisory EEC with a mechanical control backup, the 
intent of this special condition is to ensure the installation of both 
the EEC and mechanical backup provide an equivalent reliability to that 
expected of a mechanical only control.
    Part 23 did not envision the use of electronic engine controls with 
either full authority controls or supervisory only controls, 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 Title 14, Code of Federal Regulations (CFR) 
21.101, Nextant Aerospace must show that the model C90A, as changed, 
continues to meet the applicable provisions of the regulations 
incorporated by reference in Type Certificate No. 3A20 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.'' The regulations incorporated by reference in 
3A20 are as follows: CAR 3, effective May 15, 1956, amendments 3-1, 3-
2, and 3-8; CAR 3, amendment 3-6; and CAR 3 Sec.  3.705, amendment 3-7. 
In addition, the certification basis includes special conditions and 
some requirements from 14 CFR parts 23, 25, 36 and SFAR 27, as noted on 
the Type Certificate Data Sheet. If the Administrator finds that the 
applicable airworthiness regulations in part 23 do not contain adequate 
or appropriate safety standards for the model C90A because of a novel 
or unusual design feature, special conditions are prescribed under the 
provisions of Sec.  21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the model C90A 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.
    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 applicant apply for a supplemental type 
certificate to modify any other model included on the

[[Page 9178]]

same type certificate to incorporate the same novel or unusual design 
feature, the FAA would apply these special conditions to the other 
model.

Novel or Unusual Design Features

    The model C90A King Air will incorporate the following novel or 
unusual design features: The installation of an Electronic Engine 
Control (EEC) system.

Discussion

    As defined in the summary section, this airplane makes use of an 
electronic engine control system in addition to 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 the 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 C90A King Air 
when modified by Nextant Aerospace. Should Nextant Aerospace apply 
later for a supplemental type certificate to modify any other model 
included on Type Certificate No. 3A20 to incorporate the same novel or 
unusual design feature, the FAA would apply these special conditions to 
that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on the model C90A airplane. It is not a rule of general applicability 
and affects only the applicant who applied to the FAA for approval of 
these features on the airplane.
    The substance of these special conditions has been subjected to the 
notice and comment period in several prior instances, identified above, 
and has been derived without substantive change from those previously 
issued. It is unlikely that prior public comment would result in a 
significant change from the substance contained herein. Therefore, 
notice and opportunity for prior public comment hereon are unnecessary 
and the FAA finds good cause, in accordance with 5 U.S. Code Sec. Sec.  
553(b)(3)(B) and 553(d)(3), 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 described above.

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 and 44701; 14 CFR 
21.16 and 21.101; and 14 CFR 11.38 and 11.19.

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 Textron Aviation (formerly 
Beechcraft); model C90A King Air airplanes modified by Nextant 
Aerospace.

1. 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 
Thrust Control (LOTC) probability of the system to exceed those allowed 
in part 33 certification.
    b. Supervisory electronic engine control system installations must 
be evaluated for environmental and atmospheric conditions, including 
lightning. The EEC system lightning and High Intensity Radiated Fields 
(HIRF) effects that would result in LOTC or an unacceptable change in 
power or thrust must be evaluated in accordance with Sec. Sec.  23.1306 
and 23.1308.
    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 their 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 February 16, 2018.
Pat Mullen,
Manager, Small Airplane Standards Branch, Aircraft Certification 
Service.
[FR Doc. 2018-04417 Filed 3-2-18; 8:45 am]
 BILLING CODE 4910-13-P