Special Conditions: Aviation Technology Group, Incorporated, Javelin Model 100; Firewalls for Fuselage Mounted Engines and Fire Extinguishing for Aft Fuselage Mounted Engines, 660-662 [E6-22647]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 72, Number 4 (Monday, January 8, 2007)]
[Proposed Rules]
[Pages 660-662]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-22647]


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Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

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Federal Register / Vol. 72, No. 4 / Monday, January 8, 2007 / 
Proposed Rules

[[Page 660]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE263; Notice No. 23-07-01-SC]


Special Conditions: Aviation Technology Group, Incorporated, 
Javelin Model 100; Firewalls for Fuselage Mounted Engines and Fire 
Extinguishing for Aft Fuselage Mounted Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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SUMMARY: This action proposes special conditions for the Aviation 
Technology Group, Incorporated, Javelin Model 100 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 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.

DATES: We must receive your comments by February 7, 2007.

ADDRESSES: Mail two copies of your comments to: Federal Aviation 
Administration, Regional Counsel, ACE-7, 901 Locust, Room 506, Kansas 
City, Missouri 64106. You may deliver two copies to the Small Airplane 
Directorate at the above address. Mark your comments: Docket No. CE263. 
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: Leslie B. Taylor, Regulations & Policy 
Branch, ACE-111, Federal Aviation Administration, Small Airplane 
Directorate, Aircraft Certification Service, 901 Locust, Kansas City, 
MO 64106; telephone (816) 329-4134; facsimile (816) 329-4090, e-mail at 
leslie.b.taylor@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data. We ask 
that you send us two copies of written comments.
    We will file in the docket all comments we receive, as well as a 
report summarizing each substantive public contact with FAA personnel 
concerning these special conditions. You can inspect the docket before 
and after the comment closing date. If you wish to review the docket in 
person, go to the address in the ADDRESSES section of this preamble 
between 7:30 a.m. and 4 p.m., Monday through Friday, except Federal 
holidays.
    We will consider all comments we receive on or before the closing 
date for comments. We will consider comments filed late if it is 
possible to do so without incurring expense or delay. We may change 
these special conditions based on the comments we receive.
    If you want the FAA to acknowledge receipt of your comments on this 
proposal, include with your comments a pre-addressed, stamped postcard 
on which the docket number appears. We will stamp the date on the 
postcard and mail it back to you.

Background

    On February 25, 2005, Aviation Technology Group, Incorporated 
applied for a type certificate for their new Javelin Model 100. The 
Javelin Model 100, is a two-place acrobatic airplane with two fuselage 
mounted turbofan engines.
    Part 23 historically addressed fire protection on multiengine 
airplanes based on the assumption that the engines are sufficiently 
separated to essentially eliminate the possibility of an engine fire 
spreading to another engine. On traditional multiengine airplanes, this 
has been achieved by locating engines on the wings separated by the 
fuselage. This configuration ensures that an engine fire on one side 
does not migrate to the opposite engine. This configuration also 
protects the opposite engine from heat radiating from the engine fire. 
Prevention, identification, and containment are traditional means of 
fire protection. 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 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 effects relatively easy.
    Title 14 CFR, part 23, did not envision the type of configuration 
of the Javelin Model 100 airplane. The Javelin Model 100 incorporates 
two turbofan engines located side-by-side in compartments in the aft 
fuselage. These engines are not in the pilots' field of view. Located 
forward of the engines is a 280 gallon fuel tank and associated 
components. Behind and above the engines are the horizontal and 
vertical tails. Passing through or near the engines are primary 
structure and systems to support these critical flight controls. With 
the location in the aft fuselage, the ability to visually detect a fire 
is minimal. The effects of a fire emanating from an enclosed engine 
installation are more varied, adverse, and more difficult to predict 
than an engine fire envisioned for typical part 23 airplanes.

[[Page 661]]

Type Certification Basis

    Under 14 CFR 21.17, Aviation Technology Group, Incorporated must 
show that the Javelin Model 100 meets the applicable provisions of part 
23, as amended by Amendments 23-1 through 23-55 thereto.
    If the Administrator finds that the applicable airworthiness 
regulations in 14 CFR part 23 do not contain adequate or appropriate 
safety standards for the Javelin Model 100 because of a novel or 
unusual design feature, special conditions are prescribed under Sec.  
21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the Javelin Model 100 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 under section 611 of Public Law 92-574, 
the ``Noise Control Act of 1972.''
    The FAA issues special conditions, as defined in Sec.  11.19, under 
Sec.  11.38, and they 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 or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model under Sec.  21.101.

Novel or Unusual Design Features

    The Javelin Model 100 will incorporate the following novel or 
unusual design features: The Javelin Model 100 incorporates two 
turbofan engines located side-by-side in compartments in the aft 
fuselage. These engines are not in the pilots' field of view. Located 
forward of the engines is a 280 gallon fuel tank and associated 
components. Behind and above the engines are the horizontal and 
vertical tails. Passing through or near the engines are primary 
structure and systems to support these critical flight controls. 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 in 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 Javelin engine location. The engines in the 
aft fuselage have the potential to affect the pitch and yaw primary 
flight controls and the fuselage and empennage structure.
    While the certification basis for the Model 100 requires that a 
fire detection system be installed 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 primary 
structure before an emergency landing could be made. Because of the 
location of critical structures and flight controls, a means to 
minimize the probability of re-ignition from occurring is necessary. 
One acceptable method to minimize re-ignition is to install a two-shot 
system. The effects of a fire emanating from an enclosed engine 
installation are more varied, adverse, and more difficult to predict 
than an engine fire envisioned for typical part 23 airplanes.

Discussion

    The engines are side-by-side in the aft fuselage so there is a need 
to maintain isolation during a fire including heat transfer from the 
engine fire to the unaffected engine. There is also a need to prevent 
flammable vapors, flammable fluids, and flame from accumulating. 
Finally, there is a need to extinguish fires.

Applicability

    As discussed above, these special conditions are applicable to the 
Javelin Model 100. Should Aviation Technology Group, Incorporated, 
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.

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.

List of Subjects in 14 CFR Part 23

    Aircraft, Aviation safety, Signs and symbols.

    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 Aviation Technology Group, Incorporated Javelin Model No. 100 
airplanes.

Fire Isolation and Extinguishing

    The fire protection system of the airplane must include features to 
isolate each fire zone from any other zone and the airplane to maintain 
isolation of the engines during a fire. Therefore, these special 
conditions mandate that the firewall required by Sec.  23.1191 be 
extended to provide firewall isolation between either engine. These 
special conditions require that heat radiating from a fire originating 
in any fire zone must not affect components, airframe structure, 
systems, or flight controls in adjacent compartments in a way that 
endangers the airplane.
    Each fire zone should be ventilated to prevent the accumulation of 
flammable vapors. It must also be designed such that it will not allow 
entry of flammable fluids, vapors, or flames from other fire zones. It 
must be designed such that it does not create an additional fire hazard 
from the discharge of vapors or fluids.
    1. SC 23.1195--Add the requirements of Sec.  23.1195 while deleting 
``For commuter category,'' adding the requirement to ``minimize the 
probability of re-ignition,'' and deleting +the statement ``An 
individual `one-shot' system may be used.''
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 and minimize the probability of re-
ignition;
    (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 
``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

[[Page 662]]

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.
    3. SC 23.1199--Add the requirements of Sec.  23.1199 while deleting 
``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 
``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 December 27, 2006.
John Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E6-22647 Filed 1-5-07; 8:45 am]
BILLING CODE 4910-13-P