[Federal Register: January 18, 2008 (Volume 73, Number 13)]
[Rules and Regulations]
[Page 3385-3387]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18ja08-3]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. CE281; Special Conditions No. 23-221-SC]
Special Conditions: Embraer S.A., Model EMB-500; Fire
Extinguishing for Aft Fuselage Mounted Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued for the Embraer Model EMB-
500 airplane. This airplane will have a novel or unusual design
feature(s) associated with aft mounted engine fire protection. 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 January 7,
2008. Comments must be received on or before February 19, 2008.
ADDRESSES: Comments on these special conditions may be mailed in
duplicate to: Federal Aviation Administration, Regional Counsel, ACE-7,
Attention: Rules Docket CE281, 901 Locust, Room 506, Kansas City,
Missouri 64106; or delivered in duplicate to the Regional Counsel at
the above address. Comments may be inspected 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:
Comments Invited
Interested persons are invited to submit such written data, views,
or arguments as they may desire. Identify the regulatory docket or
special condition number and submit comments 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. If you wish the FAA to acknowledge receipt of the comments
submitted in response to this notice, include a self-addressed, stamped
postcard on which the following statement is made: ``Comments to Docket
No. CE281.'' The postcard will be date stamped and returned to the
commenter.
Background
On October 5, 2005, Embraer S.A. applied for a type certificate for
their new Model EMB-500. The Model EMB-500 is a normal category, low-
winged monoplane with ``T'' tailed vertical and horizontal stabilizers,
retractable tricycle type landing gear and twin turbofan engines
mounted on the aircraft fuselage. Its design characteristics include a
predominance of metallic construction. The maximum takeoff weight is
9,700 pounds, the VMO/MMO is 275 KIAS/M 0.70 and
maximum altitude is 41,000 feet.
14 CFR 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 been provided by locating engines
within the pilots' primary field of view and/or with the incorporation
of fire detection systems. This has provided both rapid detection of a
fire and confirmation when it was extinguished. Containment has been
provided through the isolation of designated fire zones, through
flammable fluid shutoff valves, and firewalls.
This containment philosophy also ensures that components of the
engine control system will function effectively to permit a safe
shutdown of an engine. However, containment has only been demonstrated
for 15 minutes. If a fire occurs in traditional part 23 airplanes, the
appropriate corrective action is to land as soon as possible. For a
small, simple airplane originally envisioned by part 23, it is possible
to descend and land within 15 minutes; thus, the occupants can safely
exit the airplane before the firewall is breached. These simple
airplanes normally have the engine located away from critical flight
control systems and primary structure. This has ensured that,
throughout a fire event, a pilot can continue safe flight, and it has
made the prediction of fire
[[Page 3386]]
effects relatively easy. Other design features of these simple
aircraft, such as low stall speeds and short landing distances, ensure
that even if an off-field landing occurs, the potential for the outcome
being catastrophic has been minimized.
Title 14 CFR part 23 did not envision the type of configuration of
the Model EMB-500 airplane. The Model EMB-500 incorporates two turbofan
engines located on pylons on either side of the aft fuselage. These
engines are not in the pilots' field of view. With the location on the
aft fuselage, the ability to visually detect a fire is minimal.
Type Certification Basis
Under the provisions of 14 CFR 21.17, Embraer S.A. must show that
the Model EMB-500 meets the applicable provisions of 14 CFR part 23, as
amended by Amendments 23-1 through 23-55, thereto.
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 23) do not contain adequate or
appropriate safety standards for the Model EMB-500 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 EMB-500 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 pursuant to section 611 of Public Law
92-574, the ``Noise Control Act of 1972.''
Special conditions, as appropriate, as defined in 11.19, are issued
under Sec. 11.38, and become part of the type certification basis
under 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 Model EMB-500 incorporates two turbofan engines located on
pylons on either side of the aft fuselage. These engines are not in the
pilots' field of view. The effects of a fire in such a compartment are
more varied and adverse than the typical engine fire in a simple part
23 airplane. With the location on the aft fuselage, the ability to
visually detect a fire is minimal. However, the ability to extinguish
an engine fire becomes extremely critical with the Model EMB-500 engine
location.
Applicability
As discussed above, these special conditions are applicable to the
Model EMB-500. Should Embraer S. A. apply later 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 Sec. 21.101(a)(1).
Good Cause
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 received. The FAA
therefore finds that good cause exists for making these special
conditions effective upon issuance.
Conclusion
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 Embraer S.
A. Model EMB-500 is imminent, the FAA finds that good cause exists to
make these special conditions effective upon issuance.
This action affects only certain novel or unusual design features
on one model, Model EMB-500, 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.
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 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 Embraer S. A. Model EMB-500 airplanes.
1. SC 23.1195--Add the requirements of Sec. 23.1195 while deleting
the phrase, ``For commuter category airplanes.''
23.1195, Fire Extinguishing Systems
(a) Fire extinguishing systems must be installed and compliance
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 extinguishing
agent, the rate of discharge, and the discharge distribution must be
adequate to extinguish fires. An individual ``one-shot'' system may be
used; and
(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.
2. SC 23.1197--Add the requirements of Sec. 23.1197 while deleting
the phrase, ``For commuter category airplanes.''
23.1197, Fire Extinguishing Agents
The following applies:
(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.
[[Page 3387]]
3. SC 23.1199--Add the requirements of Sec. 23.1199 while deleting
the phrase, ``For commuter category airplanes.''
23.1199, Extinguishing Agent Containers
The following applies:
(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 fire
extinguishing agent, each container must be installed so that
temperature conditions will not cause hazardous deterioration of the
pyrotechnic capsule.
4. SC 23.1201--Add the requirements of Sec. 23.1201 while deleting
the phrase, ``For commuter category airplanes.''
23.1201, Fire Extinguishing System Materials
The following apply:
(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 January 7, 2008.
John Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-849 Filed 1-17-08; 8:45 am]
BILLING CODE 4910-13-P