[Federal Register Volume 67, Number 137 (Wednesday, July 17, 2002)]
[Proposed Rules]
[Pages 46927-46928]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-18017]



[[Page 46927]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE171; Notice No. 23-01-04-SC-A]


Special Conditions: Eclipse Aviation Corporation, Model 500; Fire 
Extinguishing System for Aft Mounted Engine Installations

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Amended notice of proposed special conditions.

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SUMMARY: This notice amends special conditions that were proposed for 
the Eclipse Aviation Corporation Model 500 airplane. The original 
proposed special conditions were published on January 29, 2002 (67 FR 
4215). This airplane design includes aft mounted turbine engines. The 
applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for this design feature. These amended 
proposed 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. These special conditions are intended to provide the same 
level of safety and meet the same intent as previously adopted special 
conditions for fire extinguishing systems for aft mounted jet engine 
installations.

DATES: Comments must be received on or before August 16, 2002.

ADDRESSES: Comments on this proposal may be mailed in duplicate to: 
Federal Aviation Administration, Regional Counsel, Attention: Rules 
Docket No. CE171, 901 Locust, Room 506, Kansas City, Missouri 64106; or 
delivered in duplicate to the Regional Counsel at the above address. 
Comments must be marked: Docket No. CE171. 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: Mr. Lowell Foster, Federal Aviation 
Administration, Aircraft Certification Service, Small Airplane 
Directorate, ACE-111, 901 Locust Street, Kansas City, Missouri, 816-
329-4111, fax 816-329-4090.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of 
these proposed special conditions by submitting such written data, 
views, or arguments as they may desire. Communications should identify 
the regulatory docket or notice 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 proposals described in this notice 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. Persons wishing the FAA to acknowledge receipt of their 
comments submitted in response to this notice must include with those 
comments a self-addressed, stamped postcard on which the following 
statement is made: ``Comments to Docket No. CE171.'' The postcard will 
be date stamped and returned to the commenter.

Background

    On July 12, 2001, Eclipse Aviation Corporation applied for a type 
certificate for their new Model 500.
    The Model 500 design includes turbine engines mounted aft on the 
fuselage, which means early visual detection of engine fire is 
precluded. The applicable existing regulations do not require fire 
extinguishing systems for engines. Aft mounted turbine engine 
installations, along with the need to protect such installed engines 
from fires, were not envisioned in the development of part 23; 
therefore, a special condition regarding fire protection for the 
engines of the Model 500 is required.

Type Certification Basis

    Under the provisions of 14 CFR 21.17, Eclipse Aviation Corporation 
must show that the Model 500 meets the following:
    (1) Applicable provisions of 14 CFR part 23, effective December 18, 
1964, as amended by Amendments 23-1 through 23-54 (September 14, 2000).
    (2) Part 34 of the Federal Aviation Regulations effective September 
10, 1990, plus any amendments in effect on the date of type 
certification.
    (3) Part 36 of the Federal Aviation Regulations effective December 
1, 1969, as amended by Amendment 36-1 through the amendment in effect 
on the date of type certification.
    (4) Noise Control Act of 1972.
    (5) Special conditions that are not relevant to these proposed 
special conditions, if any;
    (6) Exemptions, if any;
    (7) Equivalent level of safety findings, if any; and
    (8) Special conditions adopted by this rulemaking action.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., part 23) do not contain adequate or appropriate 
safety standards for the Model 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 500 must comply with the part 23 fuel vent and 
exhaust emission requirements of 14 CFR part 34 and the part 23 noise 
certification requirements of 14 CFR part 36, and 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 Sec. 11.19, are 
issued in accordance with Sec. 11.38 after public notice 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.

Novel or Unusual Design Features

    The Eclipse Aviation Corporation Model 500 will incorporate the 
following novel or unusual design feature:
    Turbine engines mounted on the aft of the fuselage. Aft mounted 
turbine engine installations need to be protected from fire since early 
visual detection of engine fires is not possible. This notice proposes 
a special condition for a fire extinguishing system for the engines of 
the Model 500.

Applicability

    As discussed above, these special conditions are applicable to the 
Eclipse Aviation Corporation Model 500. The engine installation used in 
the Model 500 does not utilize additional engine compartments other 
than those addressed in the special conditions. Should Eclipse Aviation 
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 under 
the provisions of Sec. 21.101.

[[Page 46928]]

Conclusion

    The originally published proposed special conditions have been 
revised to clarify that the intent of the proposed rule is to require a 
fire extinguishing system (reference 14 CFR part 23, 
Sec. 23.1195(a)(1)) only if a fire is not controllable, and to remove 
the references to engine compartments that do not exist in this engine 
installation configuration. This amended special condition does not 
change the original technical requirements of the proposed special 
conditions that were the same as the previous requirements applied to 
part 23 airplanes with aft mounted turbine engines. The Eclipse Model 
500 powerplant installation does not have a traditional jet engine 
nacelle design and does not perform the function of what is considered 
a traditional nacelle from a fire hazard standpoint. Areas that a fire 
extinguishing system would normally protect against fire hazards, such 
as nacelle compartments that can accumulate (pool) flammable fluids 
that can ignite and support combustion, do not exist in the Model 500 
engine nacelle design. Therefore, this rule requires the applicant to 
show that the chosen control means is effective for any fire 
originating in the engine nacelle area under all operating conditions, 
including worst case critical conditions. If the applicant cannot meet 
this requirement as proposed, then a fire extinguishing system as 
defined in this publication will be required. These revised special 
conditions were coordinated and concurred with by the applicant. 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 Eclipse Model 500 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 Proposed Special Conditions

    Accordingly, the Federal Aviation Administration (FAA) proposes the 
following special conditions as part of the type certification basis 
for the Eclipse Aviation Corporation Model 500.

Engine Fire Extinguishing System

    (a) Fires originating in combustor, turbine, and tailpipe sections 
of the engine installation which contain lines or components carrying 
flammable fluids must either:
    (1) be demonstrated at critical conditions to be controllable by 
test or a combination of test or analysis; or
    (2) a fire extinguishing system must serve each engine compartment.
    (b) If a fire extinguishing system is installed, the system must 
comply with the following requirements:
    (1) The system must serve each engine compartment;
    (2) The 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; and
    (3) For a nacelle, the system must be able to simultaneously 
protect each compartment of the nacelle for which protection is 
provided.
    (c) If a fire extinguishing system is installed, fire extinguishing 
agents must meet the following requirements:
    (1) Be capable of extinguishing flames emanating from any burning 
of fluids or other combustible materials in the area protected by the 
fire extinguishing system;
    (2) Have thermal stability over the temperature range likely to be 
experienced in the compartment in which they are stored; and
    (3) If any toxic extinguishing agent is used, provisions must be 
made to prevent harmful concentrations of fluid or vapors from entering 
any personnel compartment even though a defect may exist in the 
extinguishing system.
    (d) If fire extinguishing agents are used, the agent containers 
must meet the following requirements:
    (1) Have a pressure relief to prevent bursting of the container by 
excessive internal pressures;
    (2) The discharge end of each discharge line from a pressure relief 
connection must be located so the 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;
    (3) 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;
    (4) The temperature of each container must be maintained, under 
intended operating conditions, to prevent the pressure in the container 
from falling below that necessary to provide an adequate rate of 
discharge, or rising high enough to cause premature discharge; and
    (5) 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.
    (e) If a fire extinguishing system is installed, system materials 
must meet the following requirements:
    (1) No material in any fire extinguishing system may react 
chemically with any extinguishing agent so as to create a hazard; and
    (2) Each system component in an engine compartment must be 
fireproof.

    Issued in Kansas City, Missouri on July 5, 2002.
James E. Jackson,
Acting Manager, Small Airplane Directorate.
[FR Doc. 02-18017 Filed 7-16-02; 8:45 am]
BILLING CODE 4910-13-P