[Federal Register Volume 73, Number 13 (Friday, January 18, 2008)]
[Rules and Regulations]
[Pages 3385-3387]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-849]


=======================================================================
-----------------------------------------------------------------------

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