[Federal Register Volume 75, Number 75 (Tuesday, April 20, 2010)]
[Rules and Regulations]
[Pages 20518-20520]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-9027]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE306; Special Conditions No. 23-246-SC]
Special Conditions: Cirrus Design Corporation Model SF50
Airplane; Full Authority Digital Engine Control (FADEC) 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 Cirrus Design
Corporation model SF50 airplane. This airplane will have a novel or
unusual design feature(s) associated with the use of an electronic
engine control system instead of a traditional mechanical 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 April 12,
2010.
We must receive your comments by May 20, 2010.
ADDRESSES: Mail two copies of your comments to: Federal Aviation
Administration, Regional Counsel, ACE-7, Attn: Rules Docket No. CE306,
901 Locust, Kansas City, MO 64106. You may deliver two copies to the
Regional Counsel at the above address. Mark your comments: Docket No.
CE306. You may inspect comments in the Rules Docket weekdays, except
Federal holidays, between 7:30 a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT: Peter L. Rouse, Federal Aviation
Administration, Aircraft Certification Service, Small Airplane
Directorate, ACE-111, 901 Locust, Room 301, Kansas City, Missouri
64106; 816-329-4135, fax 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 design
approval and thus delivery of the affected aircraft. In addition, the
substance of these special conditions has been subject to the public
comment process in several prior instances with no substantive comments
[[Page 20519]]
received. The FAA therefore finds that good cause exists for making
these special conditions effective upon issuance.
Comments Invited
Interested persons are invited to submit such written data, views,
or arguments as they may desire. Communications should identify the
regulatory docket or special condition number and be submitted in
duplicate to the address specified above. All communications received
on or before the closing date for comments will be considered by the
Administrator. The special conditions may be changed in light of the
comments received.
All comments received will be available in the Rules Docket for
examination by interested persons, both before and after the closing
date for comments. A report summarizing each substantive public contact
with FAA personnel concerning this rulemaking will be filed in the
docket.
Commenters' wishing the FAA to acknowledge receipt of their
comments submitted in response to this notice must include a self-
addressed, stamped postcard on which the following statement is made:
``Comments to Docket No. CE306.'' The postcard will be date stamped and
returned to the commenter.
Background
On September 9, 2008, Cirrus Design Corporation applied for a type
certificate for their new model SF50. The Cirrus Design Corporation
model SF50 is a low-wing, five-plus-two-place (2 children), single-
engine turbofan-powered aircraft. It incorporates an Electronic Flight
Information System (EFIS), pressurized cabin, retractable gear, and a
V-tail. The turbofan engine is mounted on the upper fuselage/tail cone
along the aircraft centerline. It is constructed largely of carbon and
fiberglass composite materials. Like other Cirrus products, the SF50
includes a ballistically deployed airframe parachute.
The model SF50 has a maximum operating altitude of 28,000 feet,
where it cruises at speeds up to 300 KTAS. Its VMO will not
exceed 0.62 Mach. The maximum takeoff weight will be at or below 6000
lbs with a range at economy cruise of roughly 1000 nm. Cirrus intends
for the model SF50 to be certified for single-pilot operations under 14
CFR part 91 and 14 CFR part 135 operating rules. The following
operating conditions will be included:
Day and Night VFR.
IFR.
Flight Into Known Icing.
The Cirrus Design Corporation model SF50 airplane is equipped with
a Williams International FJ33-5A turbofan engine using an electronic
engine control system (FADEC) instead of a traditional mechanical
control system. Even though the engine control system will be
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, for example, 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. 23.1309.
However, when Sec. 23.1309 was developed, the use of electronic
control systems for engines was not envisioned. Therefore, the Sec.
23.1309 requirements were not applicable to systems certificated as
part of the engine (reference Sec. 23.1309(f)(1)). Parts of the system
that are not certificated with the engine could be evaluated using the
criteria of Sec. 23.1309. However, the integral nature of these
systems makes it unfeasible to evaluate the airplane portion of the
system without including the engine portion of the system.
In some cases, the airplane that the engine is used in will
determine a higher classification than the engine controls are
certificated for, requiring the FADEC systems be analyzed at a higher
classification. As of November 2005, FADEC special conditions mandated
the classification for 23.1309 analysis for loss of FADEC control as
catastrophic for any airplane. This is not to imply an engine failure
is classified as catastrophic, but that the digital engine control must
provide an equivalent reliability to mechanical engine controls.
Type Certification Basis
Under the provisions of 14 CFR part 21, Sec. 21.17, Cirrus Design
Corporation must show that the model SF50 meets the applicable
provisions of part 23, as amended by Amendments 23-1 through 23-59,
thereto.
If the Administrator finds that the applicable airworthiness
regulations (i.e., part 23) do not contain adequate or appropriate
safety standards for the model SF50 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 SF50 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. Also, the FAA must issue a finding of
regulatory adequacy pursuant to Sec. 611 of Public Law 92-574, the
``Noise Control Act of 1972.''
Special conditions, as appropriate, as defined in 11.19, are issued
in accordance with Sec. 11.38, and become part of the type
certification basis in accordance with Sec. 21.17(a)(2).
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, the special conditions would also apply to the
other model under the provisions of Sec. 21.101(a)(1).
Novel or Unusual Design Features
The Cirrus Design Corporation model SF50 will incorporate the
following novel or unusual design features:
Electronic engine control system.
Applicability
As discussed above, these special conditions are applicable to the
model SF50. Should Cirrus Design Corporation 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 special conditions would
apply to that model as well as under the provisions of Sec.
21.101(a)(1).
Conclusion
This action affects only certain novel or unusual design features
on the model SF50 airplanes. It is not a rule of general applicability
and it affects only the applicant who applied to the FAA for approval
of these features on the airplane.
Under standard practice, the effective date of final special
conditions would be 30 days after the date of publication in the
Federal Register; however, as the certification date for the Cirrus
Design Corporation model SF50 is imminent, the FAA finds that good
cause exists to make these special conditions effective upon issuance.
List of Subjects in 14 CFR Part 23
Aircraft, Aviation safety, Signs and symbols.
Citation
0
The authority citation for these special conditions is as follows:
[[Page 20520]]
Authority: 49 U.S.C. 106(g), 40113 and 44701; 14 CFR 21.16 and
21.17; 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 Cirrus Design Corporation model SF50
airplanes.
1. Electronic Engine Control
The installation of the electronic engine control system must
comply with the requirements of 14 CFR 23.1309(a) through (e) at
Amendment 23-49. The intent of this requirement is not to reevaluate
the inherent hardware reliability of the control itself, but rather
determine the effects, including environmental effects addressed in 14
CFR 23.1309(e), on the airplane systems and engine control system when
installing the control on the airplane. When appropriate, engine
certification data may be used when showing compliance with this
requirement; however, the effects of the installation on this data must
be addressed.
For these evaluations, the loss of FADEC control will be analyzed
utilizing the threat levels associated with a catastrophic failure.
Issued in Kansas City, Missouri, on April 12, 2010.
Steve Thompson,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-9027 Filed 4-19-10; 8:45 am]
BILLING CODE 4910-13-P