[Federal Register Volume 72, Number 244 (Thursday, December 20, 2007)]
[Proposed Rules]
[Pages 72265-72270]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 07-6129]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE275; Notice No. 23-07-04-SC]


Special Conditions: Aviation Technology Group, Inc., Javelin 
Model 100; High Altitude Operations

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, Inc., Javelin Model 100 airplane. This airplane will 
have a novel or unusual design feature(s) associated with high altitude 
operations. The applicable airworthiness regulations do not contain 
adequate or appropriate safety standards for these design features. 
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 January 22, 2008.

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. CE275. 
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 
[email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite interested parties 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 may 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 15, 2005, Aviation Technology Group (ATG), 8001 S. 
InterPort Blvd., Englewood, CO 80112 applied for a type certificate for 
their new Javelin Model 100 airplane. The Javelin Model 100 is a two-
seat, pressurized, retractable-gear, composite airplane with two 
turbofan engines mounted in the aft fuselage.
    The Aviation Technology Group, Inc. (ATG) Javelin Model 100 will be 
certificated for operations at a maximum altitude of 45,000 feet. This 
unusually high operating altitude constitutes a novel or unusual design 
feature for which the applicable airworthiness regulations do not 
contain adequate or appropriate safety standards. Therefore, it is 
necessary to develop special conditions that provide the level of 
safety equivalent to that established by the regulations.
    ATG indicated they will fully comply with Special Conditions for 
a., Pressure Vessel Integrity; b., Ventilation; and c., Air 
Conditioning.
    However, ATG is unable to fully comply with Special Conditions d. 
Pressurization and e. Oxygen equipment and supply. As a result from 
these discussions, the Special Conditions d. and e. were revised to 
include an alternate means or compensating features that require the 
use of an oxygen system and emergency descent procedures that addresses 
a rapid decompression event.

Discussion

    The 14 CFR part 23 certification basis for the ATG Javelin Model 
100 is part 23, Amendment 23-55. The FAA issues high altitude special 
conditions for airplanes when the certificated altitude exceeds human 
physiological limits.
    Crack growth could result in rapid depressurization to cabin 
altitudes that exceed human physiological limits. Damage tolerance 
methods are proposed to be used to assure pressure vessel integrity 
while operating at the higher altitudes. Crack growth data is used to 
prescribe an inspection program, which will detect cracks before an 
opening in the pressure vessel would allow rapid depressurization. 
Initial crack sizes for detection are determined under Sec.  23.571, 
Amendment 23-55. The cabin altitude after permissible crack growth may 
not exceed specified limits.
    To ensure that there is adequate fresh air for crewmembers to 
perform their duties, to provide reasonable passenger comfort, and to 
enable occupants to better withstand the effects of decompression at 
high altitudes, the ventilation system must be designed to provide 10 
cubic feet of fresh air per minute per person during normal operations. 
Therefore, these special conditions require that crewmembers and 
passengers be provided with 10 cubic feet of fresh air per minute per 
person. In addition, during the development of the supersonic transport 
special conditions, it was noted that certain pressurization failures 
resulted in hot ram or bleed air being used to maintain pressurization. 
Air conditioning special conditions are required because such a measure 
can lead to cabin temperatures that exceed human tolerance limits 
following probable and improbable failures.
    Continuous flow passenger oxygen equipment is certificated for use 
up to 40,000 feet; however, for rapid decompressions above 34,000 feet, 
reverse diffusion leads to low oxygen partial pressures in the lungs, 
to the extent that a small percentage of

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passengers may lose useful consciousness at 35,000 feet. The percentage 
increases to an estimated 60 percent at 40,000 feet, even with the use 
of the continuous flow system. To prevent permanent physiological 
damage, the cabin altitude must not exceed 25,000 feet for more than 2 
minutes, or 40,000 feet for any time period. The maximum peak cabin 
altitude of 40,000 feet is consistent with the standards established 
for previous certification programs.
    Decompression above 37,000 feet can result in cabin altitudes that 
approach the physiological limits of the average person; therefore, 
every effort must be made to provide the pilot with adequate oxygen 
equipment to withstand these severe decompressions. Reducing the time 
interval between pressurization failure and the time the pilot receives 
oxygen will provide a safety margin against being incapacitated and can 
be accomplished by the use of mask-mounted regulators. The proposed 
special condition, therefore, requires pressure demand masks with mask-
mounted regulators for the flight crew. This combination of equipment 
will provide the best practical protection for the failures covered by 
the proposed special conditions and for improbable failures not covered 
by the special conditions, provided the cabin altitude is limited.

Type Certification Basis

    Under 14 CFR part 21, Sec.  21.17, Aviation Technology Group, Inc. 
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 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 Sec.  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:
    Part 23 did not envision operation at the service ceiling requested 
for this airplane. The methods used to ensure pressure vessel integrity 
and to provide ventilation, air conditioning, pressurization, and 
supplemental oxygen will be unique due to that operating altitude.

Applicability

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

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 Aviation Technology Group, Inc., Javelin Model 100 airplanes.
    a. Pressure Vessel Integrity.
    1. The maximum extent of failure and pressure vessel opening that 
can be demonstrated to comply with paragraph d (Pressurization) of this 
special condition must be determined. It must be demonstrated by crack 
propagation and damage tolerance analysis supported by testing that a 
larger opening or a more severe failure than demonstrated will not 
occur in normal operations.
    2. Inspection schedules and procedures must be established to 
ensure that cracks and normal fuselage leak rates will not deteriorate 
to the extent that an unsafe condition could exist during normal 
operation.
    b. Ventilation. In lieu of the requirements of Sec.  23.831(b), the 
ventilation system must be designed to provide a sufficient amount of 
uncontaminated air to enable the crewmembers to perform their duties 
without undue discomfort or fatigue, and to provide reasonable 
passenger comfort during normal operating conditions and also in the 
event of any probable failure of any system which could adversely 
affect the cabin ventilating air. For normal operations, crewmembers 
and passengers must be provided with at least 10 cubic feet of fresh 
air per minute per person, or the equivalent in filtered, recirculated 
air based on the volume and composition at the corresponding cabin 
pressure altitude of not more than 8,000 feet.
    c. Air Conditioning. In addition to the requirements of Sec.  
23.831, paragraphs (b), the cabin cooling system must be designed to 
meet the following conditions during flight above 15,000 feet mean sea 
level (MSL):
    1. After any probable failure, the cabin temperature-time history 
may not exceed the values shown in Figure 1. (Please see Advisory 
Circular (AC) 23.1309-1C, pages 10 and 16.)
    2. After any improbable failure, the cabin temperature-time history 
may not exceed the values shown in Figure 2. (Please see AC 23.1309-1C, 
pages 9 and 16.)
    d. Pressurization: In addition to the requirements of Sec.  23.841, 
the following revised Special Condition was designed to limit high 
altitude exposure by slowing down the depressurization event and to 
mitigate or eliminate acute affects of dangerously low atmospheric 
pressure on flight crew and passengers.
    1. For the purposes of this special condition, the pressurization 
system includes bleed air, air conditioning, and pressure control 
systems. The pressurization system must prevent the cabin altitude from 
exceeding the cabin altitude-time history shown in Figure 3 after each 
of the following:
    (a) Any probable malfunction or failure of the pressurization 
system. The existence of undetected, latent malfunctions or failures in 
conjunction with probable failures must be considered.
    (b) Any single failure in the pressurization system combined with 
the occurrence of a leak produced by a complete loss of a door seal 
element, or a fuselage leak through an opening

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having an effective area 2.0 times the effective area, which produces 
the maximum permissible fuselage leak rate approved for normal 
operation, whichever produces a more severe leak.

    Note: The ATG Javelin Model 100 proposes to use a mechanical 
canopy seal that is not subject to complete loss of the door seal 
element. ATG must still show compliance by analysis and/or test a 
fuselage leak through an opening having an effective area 2.0 times 
the effective area that produces the maximum permissible fuselage 
leak rate approved for normal operation.

    2. The cabin altitude-time history may not exceed that shown in 
Figure 4 after each of the following:
    (a) The maximum pressure vessel opening resulting from an initially 
detectable crack propagating for a period encompassing four normal 
inspection intervals. Mid-panel cracks and cracks through skin-stringer 
and skin-frame combinations must be considered.
    (b) The pressure vessel opening or duct failure resulting from 
probable damage (failure effect) while under maximum operating cabin 
pressure differential due to a tire burst, engine rotor burst, loss of 
antennas or stall warning vanes, or any probable equipment failure 
(bleed air, pressure control, air conditioning, electrical source(s), 
etc.) that affects pressurization.
    3. Complete loss of thrust from all engines. In showing compliance 
with paragraphs d.1 and d.2 of these special conditions 
(Pressurization), it may be assumed that an emergency descent is made 
by an approved emergency procedure. A 5-second crew recognition and 
reaction time must be applied between cabin altitude warning and the 
initiation of an emergency descent.
    The additional Special Conditions below show full compliance to 
paragraphs d.1. and d.2. and are applicable to both aircraft models. 
Special Conditions that are aircraft model specific will be noted as 
Mk-10 or Mk-20.
    4. A decompression event is considered to be a rapid decompression 
event; therefore, the following requirements must be met: The airplane 
design must include an auto descent feature. The AFM must contain 
specific instructions for its use, including considerations for air 
traffic conditions, terrain awareness, annunciation, and accessibility 
to the control(s) for automatic initiation of the descent sequence by 
each occupant.

    Note: For the flight evaluation of the rapid descent, the test 
article must have the cabin volume representative of what is 
expected to be normal, such that ATG must reduce the total cabin 
volume by that which would be occupied by the furnishings and total 
number of people.

    5. ATG must provide flight crew and crewmember training 
requirements, including physiological training that covers--
    (a) Pressure or reverse cycle breathing,
    (b) Rapid decompression training,
    (c) Physical condition with respect to the hazards of high altitude 
rapid decompression, and
    (d) Recognition of decompression sickness symptoms and the need for 
medical treatment.
    6. The oxygen system must be compatible with paragraph e, Oxygen 
Equipment and Supply Special Conditions.
    (a) Mk-10: The flight crew and passenger(s) are required to use 
oxygen masks for all operating altitudes above 25,000 feet.
    (b) Mk-20: The flight crew and crewmember are required to use 
oxygen masks for all operating altitudes above 10,000 feet.
    7. ATG will show a means of guarding or de-activating the automatic 
``auto emergency descent'' mode control in the forward or aft cockpit 
to prevent inadvertent descent mode activation. Appropriate placards 
will be required for each control device.
    8. ATG will show a means of guarding or de-activating the in-flight 
jettison canopy control, canopy fracturing system, or any other safety 
critical control device in the forward or aft cockpit to prevent 
inadvertent activation. Appropriate placards will be required for each 
control device.
    9. Cabin pressure loss must be annunciated as a warning. (See 
Equivalent Level of Safety Findings for Cabin Pressurization.)
    10. The AFM will include:
    (a) Mk-10: Require a passenger briefing concerning items 4 through 
9 above and the following:
    (i) Seat belts.
    (ii) Emergency exit.
    (iii) Use of quick-donning oxygen mask system with a pressure-
demand as described in paragraph e2, Oxygen Equipment and Supply.
    (b) Mk-20: Required flight crew and crewmember briefing concerning 
items 4 through 10(a) above.
    (i) The flight crew is the pilot and crewmember, which means a 
person assigned to perform duty in an aircraft during flight time. The 
Mk-20 poses safety concerns for a typical passenger since additional 
training beyond the pre-flight briefing may be required to use the 
emergency egress system (i.e., ejection seat). Each occupant of the Mk-
20 will be considered as a flight crew or crewmember and be required to 
complete the minimum requisite training in paragraph d5 before flying 
on the airplane.
    e. Oxygen equipment and supply. After several follow-on FAA/ATG 
discussions, the FAA Position Stage 3 for the Mk-10/Mk-20 Special 
Conditions e.1 and e.2 were revised to include quick-donning pressure-
demand oxygen mask or an alternate helmet mounted oxygen mask for both 
occupants that complies with TSO-C89 requirements up to 45,000 feet. 
Furthermore, Special Condition e.3 was revised to allow a common oxygen 
source with a larger capacity as an alternate means or compensating 
feature.
    1. In addition to the requirements of Sec.  23.1441(d), the 
following applies: A quick-donning oxygen mask system with a pressure-
demand, mask mounted regulator that complies with TSO-C89 requirements 
up to 45,000 feet must be provided for the flight crew. It must be 
shown that each quick-donning mask can, with one hand and within 5 
seconds, be placed on the face from its ready position, properly 
secured, sealed, and supplying oxygen upon demand. Alternately, a 
helmet mounted oxygen mask, panel mounted regulator that complies with 
TSO-C89 requirements up to 45,000 feet may be provided to the flight 
crew.
    2. In addition to the requirements of Sec.  23.1443, the following 
applies: A quick-donning oxygen mask system with a pressure-demand, 
mask mounted regulator that complies with TSO-C89 requirements up to 
45,000 feet must be provided for the passenger or crewmember. 
Alternately, a helmet mounted oxygen mask, panel mounted regulator that 
complies with TSO-C89 requirements up to 45,000 feet may be provided to 
the passenger.
    3. In addition to the requirements of Sec.  23.1445, the following 
applies: If the flight crew and passenger/crewmember share a common 
source of oxygen, a means to separately reserve the minimum supply 
required by the flight crew must be provided. Alternately, if the 
oxygen system can provide the minimum required for the flight crew as 
well as all other occupants, the system can have a common source.
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    Issued in Kansas City, Missouri on December 12, 2007.
James E. Jackson,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 07-6129 Filed 12-19-07; 8:45 am]
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