[Federal Register: September 23, 2008 (Volume 73, Number 185)]
[Rules and Regulations]
[Page 54675-54677]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23se08-7]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE287, Special Conditions No. 23-227-SC]
Special Conditions; Honda Aircraft Company, Model HA-420 HondaJet
Airplane; Fire Extinguishing
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
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SUMMARY: This notice issues special conditions for the Honda Aircraft
[[Page 54676]]
Company, Model HA-420 HondaJet Airplane. This new airplane will have
novel and unusual design features not typically associated with normal,
utility, acrobatic, and commuter category airplanes. These design
features include turbofan engines and engine location, for which the
applicable regulations do not contain adequate or appropriate
airworthiness standards. These special conditions contain the
additional airworthiness standards that the Administrator considers
necessary to establish a level of safety equivalent to that established
by the existing airworthiness standards.
DATES: Effective Date: September 15, 2008.
FOR FURTHER INFORMATION CONTACT: Leslie B. Taylor, Aerospace Engineer,
Standards Office (ACE-110), Small Airplane Directorate, Aircraft
Certification Service, Federal Aviation Administration, Room 301, 901
Locust Street, Kansas City, Missouri 64106; telephone (816) 329-4134,
e-mail: leslie.b.taylor@faa.gov.
SUPPLEMENTARY INFORMATION:
Background
On October 11, 2006, Honda Aircraft Company, Greensboro, North
Carolina, made an application to the FAA for a new Type Certificate for
the Honda Model HA-420 HondaJet. The Honda Model HA-420 HondaJet is an
all new very light jet, twin engine, high performance, low wing, aft
overwing mounted turbofan engine powered aircraft in the normal
category including flight into known icing conditions, Reduced Vertical
Separation Minima (RVSM) and single pilot operations. The Model HA-420
HondaJet design criteria includes: 9963 pounds maximum gross weight,
estimated maximum speed of 258 KIAS/0.72 Mach, cruise speed of 420 KTAS
at 30,000 feet, and a 43,000 foot maximum altitude.
Part 23 has historically addressed fire protection through
prevention, identification, and containment. Prevention has been
provided through minimizing the potential for ignition of flammable
fluids and vapors. Identification has traditionally been provided by
the location of the engines within the pilot's primary field of view
and/or with the incorporation of fire detection systems. This
philosophy has provided for both the rapid detection of a fire and
confirmation when it has been extinguished. Containment has been
provided through the isolation of designated fire zones through
flammable fluid shutoff valves and firewalls. The containment
philosophy also ensures that components of the engine control system
will function effectively to permit a safe shutdown of the engine.
However, containment has only been required to be demonstrated for 15
minutes. In event of a fire in a traditional part 23 airplane, the
corrective action is to land as soon as possible. For a small, simple
aircraft originally envisioned by part 23, it is possible to descend
the aircraft to a suitable landing site within 15 minutes. Thus, if the
fire is not extinguished, the occupants can safely exit the aircraft
before the firewall is breached. These simple and traditional aircraft
normally have the engine located away from critical flight control
systems and primary structure. This has ensured that, throughout the
fire event, the pilot can continue safe flight and control. It has also
made predicting the effects of a fire relatively easy. Other design
features of these simple and traditional aircraft, such as low stall
speeds and short landing distances, ensure that, even in the event of
an off-field landing, the potential for a catastrophic outcome has been
minimized.
The certification basis for the Model HA-420 HondaJet does require
that a fire detection system be installed. However, due to the engine
location, fire extinguishing is also considered a requirement. A
sustained fire could result in loss of control of the airplane and
damage to the primary structure before an emergency landing could be
made.
Type Certification Basis
Under the provisions of 14 CFR, part 21, Sec. 21.17, Honda
Aircraft Company must show that the Model HA-420 HondaJet meets the
applicable provisions of 14 CFR, part 23, effective February 1, 1965,
as amended by Amendments 23-1 through Amendment 23-55, effective March
1, 2002; 14 CFR, part 36, effective December 1, 1969, through the
amendment effective on the date of type certification; 14 CFR, part 34;
exemptions, if any; and the special conditions adopted by this
rulemaking action.
Discussion
Special conditions, as appropriate, as defined in Sec. 11.19, are
issued in accordance with Sec. 11.38, and become part of the type
certification basis in accordance with Sec. 21.17.
Novel or Unusual Design Features
The Honda Aircraft Company, Model HA-420 HondaJet will incorporate
the following novel or unusual design features:
Engine Fire Extinguishing System
The Model HA-420 HondaJet design includes engines mounted aft on
the top of the wings; therefore, early visual detection of engine fires
is precluded. The applicable existing regulations do not require fire
extinguishing systems for engines. Aft mounted engine installations
were not envisaged in the development of part 23; therefore, special
conditions for a fire extinguishing system with the applicable agents,
containers, and materials for the engines of the Model HA-420 HondaJet
are appropriate.
Discussion of Comments
A notice of proposed special conditions, Notice No. 23-08-04-SC,
for the Model HA-420 HondaJet was published on June 25, 2008 (73 FR
35979). No comments were received, and the special conditions are
adopted as proposed.
Applicability
As discussed above, these special conditions are applicable to the
Model HA-420 HondaJet. Should Honda Aircraft Company 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 under the provisions of
Sec. 21.101.
Conclusion
This action affects only certain novel or unusual design features
on one model of airplane. 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 identified.
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(g); 40113 and 44701; 14 CFR 21.16 and
21.17; and 14 CFR 11.38 and 11.19.
The Final Special Conditions
Accordingly, the Federal Aviation Administration (FAA) issues the
following special conditions as part of the type certification basis
for the Honda Aircraft Company, Model HA-420 HondaJet airplane:
SC 23.1195, Fire extinguishing systems--Add the requirements of 14
CFR Sec. 23.1195 as modified below while deleting, ``For commuter
category airplanes.''
[[Page 54677]]
(a) Fire extinguishing systems must be installed and compliance
must be shown with the following:
(1) Except for combustor, turbine, and tailpipe sections of
turbine-engine installations that contain lines or components carrying
flammable fluids or gases for which a fire originating in these
sections is shown to be controllable, a fire extinguisher system must
serve each engine compartment.
(2) The fire extinguishing system, the quantity of the
extinguishing agent, the rate of discharge, and the discharge
distribution must be adequate to extinguish fires. An individual ``one
shot'' system may be used except for embedded engines where a ``two-
shot'' system is required.
(3) The fire extinguishing system for a nacelle must be able to
simultaneously protect each compartment of the nacelle for which
protection is provided.
(b) If an auxiliary power unit is installed in any airplane
certificated to this part, that auxiliary power unit compartment must
be served by a fire extinguishing system meeting the requirements of
paragraph (a)(2) of this section.
SC 23.1197, Fire extinguishing agents--Add the requirement of 14
CFR Sec. 23.1197 while deleting, ``For commuter category airplanes.''
(a) Fire extinguishing agents must:
(1) Be capable of extinguishing flames emanating from any burning
fluids or other combustible materials in the area protected by the fire
extinguishing system; and
(2) Have thermal stability over the temperature range likely to be
experienced in the compartment in which they are stored.
(b) If any toxic extinguishing agent is used, provisions must be
made to prevent harmful concentrations of fluid or fluid vapors (from
leakage during normal operation of the airplane or as a result of
discharging the fire extinguisher on the ground or in flight) from
entering any personnel compartment, even though a defect may exist in
the extinguishing system. This must be shown by test except for built-
in carbon dioxide fuselage compartment fire extinguishing systems for
which:
(1) Five pounds or less of carbon dioxide will be discharged, under
established fire control procedures, into any fuselage compartment; or
(2) Protective breathing equipment is available for each flight
crewmember on flight deck duty.
SC 23.1199, Extinguishing agent containers--Add the requirements of
14 CFR Sec. 23.1199 while deleting, ``For commuter category
airplanes.''
(a) Each extinguishing agent container must have a pressure relief
to prevent bursting of the container by excessive internal pressures.
(b) The discharge end of each discharge line from a pressure relief
connection must be located so that discharge of the fire extinguishing
agent would not damage the airplane. The line must also be located or
protected to prevent clogging caused by ice or other foreign matter.
(c) A means must be provided for each fire extinguishing agent
container to indicate that the container has discharged or that the
charging pressure is below the established minimum necessary for proper
functioning.
(d) The temperature of each container must be maintained, under
intended operating conditions, to prevent the pressure in the container
from--
(1) Falling below that necessary to provide an adequate rate of
discharge, or
(2) Rising high enough to cause premature discharge.
(e) If a pyrotechnic capsule is used to discharge the extinguishing
agent, each container must be installed so that temperature conditions
will not cause hazardous deterioration of the pyrotechnic capsule.
SC 23.1201, Fire extinguishing systems materials--Add the
requirements of Sec. 23.1201 while deleting, ``For commuter category
airplanes.''
Fire extinguisher system materials must meet the following
requirements:
(a) No material in any fire extinguishing system may react
chemically with any extinguishing agent so as to create a hazard.
(b) Each system component in an engine compartment must be
fireproof.
Issued in Kansas City, Missouri on September 15, 2008.
John Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-22154 Filed 9-22-08; 8:45 am]
BILLING CODE 4910-13-P