[Federal Register: August 4, 2008 (Volume 73, Number 150)]
[Rules and Regulations]
[Page 45156-45158]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04au08-2]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM390; Special Conditions No. 25-372-SC]
Special Conditions: Embraer S.A., Model ERJ 190-100 ECJ Airplane;
Fire Protection
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
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SUMMARY: These special conditions are issued for the Embraer S.A.,
Model ERJ 190-100 ECJ airplane. This airplane has a novel or unusual
design feature, in that it features multiple electrical/electronic
equipment bays that are located throughout the airplane. 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: Effective Date: September 3, 2008.
FOR FURTHER INFORMATION CONTACT: Stephen Happenny, FAA, Propulsion/
Mechanical Branch, ANM-112, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone 425-227-2147; facsimile 425-227-1232.
SUPPLEMENTARY INFORMATION:
Background
Embraer S.A., made the original application for certification of
the Model ERJ 190 on May 20, 1999. The Embraer application includes six
different models, the initial variant being designated as the Model ERJ
190-100. The application was submitted concurrently with that for the
Model ERJ 170-100, which received an FAA type certificate (TC) on
February 20, 2004. Although the applications were submitted as two
distinct TCs, the airplanes share the same conceptual design and
general configuration. On July 2, 2003, Embraer S.A., submitted a
request for an extension of its original application for the Model ERJ
190 series, with a new application date of May 30, 2001, for
establishing the type certification basis. The FAA certification basis
was adjusted to reflect this new application date. In addition, Embraer
has elected to voluntarily
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comply with certain 14 CFR part 25 amendments introduced after the May
30, 2001, application date.
On May 30, 2001, Embraer S.A., amended the application to include
the Model ERJ 190-100 ECJ. The Model ERJ 190-100 ECJ is a derivative of
the Model ERJ 190 which is approved under Type Certificate No. A57NM.
The Model ERJ 190-100 ECJ is a low wing, transport-category airplane
powered by two wing-mounted General Electric CF34-10E6 turbofan
engines. The airplane is a 19 passenger regional jet with a maximum
takeoff weight of 54,500 kilograms (120,151 pounds). The maximum
operating altitude and speed are 41,000 feet and 320 knots calibrated
air speed (KCAS)/0.82 MACH, respectively. The Model ERJ 190-100 ECJ
design includes multiple electrical/electronic equipment bays that are
located throughout the airplane.
Type Certification Basis
Under the provisions of Sec. 21.101, Embraer S.A. must show that
the Model ERJ 190-100 ECJ meets the applicable provisions of the
regulations incorporated by reference in Type Certificate No. A57NM or
the applicable regulations in effect on the date of application for the
change to the Model ERJ 190-100 ECJ. The regulations incorporated by
reference in the type certificate are commonly referred to as the
``original type certification basis.''
If the Administrator finds that the applicable airworthiness
regulations (i.e., part 25) do not contain adequate or appropriate
safety standards for the Model ERJ 190-100 ECJ 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 ERJ 190-100 ECJ 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.
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. 21.101.
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, or should any other model already
included on the same type certificate be modified to incorporate 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 Embraer S.A., Model ERJ 190-100 ECJ will incorporate the
following novel or unusual design feature: Multiple electrical/
electronic equipment bays located in the lower lobe and on the main
deck of the airplane. These bays are an unusual design relative to
those which have been previously certificated under 14 CFR part 25. The
number and location of the electrical/electronic equipment bays on the
Model ERJ 190-100 ECJ may contribute to an increased risk of smoke
affecting passengers and crew.
Discussion
Section 25.855 contains the material standards and design
considerations for cargo compartment interiors; the statement that each
cargo compartment must meet one of the class requirements of Sec.
25.857; and the flight tests which must be conducted for certification.
Section 25.857 provides the standards for the various classes of
transport category airplane cargo compartments including a smoke
detector; means to shutoff the ventilating airflow; and a means to
exclude hazardous quantities of smoke or fire extinguishing agent from
penetrating into occupied areas of the airplane. Section 25.858
requires certain provisions be made for smoke detection. However, there
are no requirements that address the following:
Preventing hazardous quantities of smoke or extinguishing
agent originating from the electrical/electronic equipment bays from
penetrating into occupied areas of the airplane; or
Installing smoke or fire detectors in electrical/
electronic equipment bays.
Generally, transport category airplanes have one or two electrical/
electronic equipment bays located in the lower lobe, adjacent to
pressure regulator/outflow valves. If there were smoke in an
electrical/electronic equipment bay, in most cases it is expected to be
drawn toward the outflow valves and be discharged from the airplane
without entering occupied areas. In the Model ERJ 190-100 ECJ, the
electrical/electronic equipment bays are distributed throughout the
airplane. Only those equipment bays located in the lower lobe of the
airplane are considered to be adjacent to pressure regulator/outflow
valves.
For this combination of electrical/electronic equipment bays
distributed throughout the airplane the applicable airworthiness
regulations do not contain adequate or appropriate safety standards
regarding smoke detection and control of smoke penetration. Based upon
its review of incidents of smoke in the passenger cabin, the FAA
determined that an airplane with electrical/electronic equipment bays
located below, on, and above the main deck of an airplane presents a
greater risk of smoke penetration than older designs with electrical/
electronic bays only in the lower lobe adjacent to pressure regulator/
outflow valves.
In the event of a fire, airplanes with older designs rely upon
``trial and error'' to determine whether the source of fire or smoke is
in the electrical/electronic equipment bay. Typically, this involves
the pilots following approved procedures in the Airplane Flight Manual.
Those procedures may involve shutting down power to the avionics
equipment in one electrical/electronic equipment bay and reconfiguring
the airplane's environmental control system (e.g., shutting down the
recirculation fan) to see whether the amount of smoke in the flightdeck
or passenger compartment is reduced or eliminated. If these actions do
not eliminate the smoke, the flight crew may turn the power back on in
the one electrical/electronic equipment bay, shut it off in the other
equipment bay, and reconfigure the environmental control system again
to see whether the smoke is now reduced or eliminated.
This approach may be acceptable for airplanes with no more than two
electrical/electronic equipment bays, both located in the lower lobe.
In that case, there are only two options: The smoke or fire in an
electrical/electronic equipment bay is in either one or the other.
However, for an airplane with electrical/electronic equipment bays
located below, on, and above decks, this approach is not sufficient,
because--in the time it takes to determine the source of smoke--a fire
could spread and the quantity of smoke could increase significantly.
Furthermore, the ``trial and error'' approach raises concern over
the lack of informational awareness that a flight crew would have
should smoke penetration occur. Many factors--including the airflow
pattern, configuration changes in the environmental control system,
potential leak paths, and location of outflow/regulator valves--would
make it difficult to identify a smoke source, especially during flight
or system transients, such as climbing/descending or changes in
ventilation.
The FAA believes that smoke detectors are needed in all electrical/
electronic equipment bays on the Model ERJ 190-100 ECJ to ensure that
the flightcrew can make an informed decision as to the source of smoke
and can shut down the specific electrical/
[[Page 45158]]
electronic equipment bay from which the smoke is coming.
These special conditions, therefore, require that there be a smoke
or fire detection system in each electrical/electronic equipment bay.
They also include requirements to prevent propagation of hazardous
quantities of smoke or fire extinguishing agent between or throughout
the passenger cabins on the main deck and the upper deck.
Discussion of Comments
Notice of proposed special conditions No. 25-08-04-SC for the
Embraer S.A., Model ERJ 190-100 ECJ airplanes was published in the
Federal Register on April 21, 2008 (73 FR 21288). A comment was
received was in favor of the proposed special conditions and these
special conditions were adopted as proposed with one correction as
defined below.
During a review of the Notice of proposed special conditions No.
25-08-04-SC for the Embraer S.A., Model ERJ 190-100 ECJ airplanes, the
FAA noted that the proposed flight test special condition demonstrating
that only a ``small quantity'' of smoke may enter an occupied area from
an electrical/electronic equipment bay is not consistent with the
``Discussion'' section of the document. The ``Discussion'' section
clearly states that electrical/electronic equipment bays located below,
on, and above the main deck of an airplane present a greater risk of
smoke penetration than older designs. The proposed flight test special
condition was inadvertently limited to smoke penetration flight tests
for electrical/electronic equipment bays located on the main deck of
the airplane. The final special condition has been corrected to reflect
the FAA's original intent to require smoke penetration flight tests
from all electrical/electronic equipment bay locations.
Applicability
As discussed above, these special conditions are applicable to the
Embraer S.A., Model ERJ 190-100 ECJ airplanes. Should Embraer S.A.,
apply at a later date for a change to the type certificate to include
another model on the same type certificate 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 Model ERJ 190-100 ECJ airplanes. It is not a rule of general
applicability.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
The Special Conditions
0
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 ERJ 190-100 ECJ
airplanes.
1. Requirements to prevent propagation of smoke or extinguishing
agents from entering the flight deck and passenger cabin:
(a) To prevent such propagation the following must be demonstrated:
A means to prevent hazardous quantities of smoke or extinguishing agent
originating from the electrical equipment bays from incapacitating
passengers and crew.
(b) A ``small quantity'' of smoke may enter an occupied area only
under the following conditions:
(1) The smoke enters occupied areas during system transients \1\
from a source located below the flight deck and passenger cabin or on
the same level as the flight deck and passenger cabin. No sustained
smoke penetration beyond that from environmental control system
transients is permitted.
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\1\ Transient airflow conditions may cause air pressure
differences between compartments, before the ventilation and
pressurization system is reconfigured. Additional transients occur
during changes to system configurations such as pack shut-down, fan
shut-down, or changes in cabin altitude; transition in bleed source
change, such as from intermediate stage to high stage bleed air; and
cabin pressurization ``fly-through'' during descent may reduce air
conditioning inflow. Similarly, in the event of a fire, a small
quantity of smoke that penetrates into an occupied area before the
ventilation system is reconfigured would be acceptable under certain
conditions described within this special condition.
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(2) Penetration of the small quantity of smoke is a dynamic event,
involving either dissipation or mobility. Dissipation is rapid dilution
of the smoke by ventilation air, and mobility is rapid movement of the
smoke into and out of the occupied area. In no case should there be
formation of a light haze indicative of stagnant airflow, as this would
indicate that the ventilation system is failing to meet the
requirements of Sec. 25.831(b).
(3) The smoke from a smoke source below the flight deck and
passenger cabin must not rise above armrest height.
(4) The smoke from a source in an electrical/electronic equipment
bay must dissipate rapidly via dilution with fresh air and be evacuated
from the airplane. A procedure must be included in the Airplane Flight
Manual to evacuate smoke from the occupied areas of the airplane. In
order to demonstrate that the quantity of smoke is small, a flight test
must be conducted which simulates the emergency procedures used in the
event of a fire during flight, including the use of Vmo/
Mmo descent profiles and a simulated landing, if such
conditions are specified in the emergency procedure.
2. Requirement for fire detection in electrical/electronic
equipment bays:
(a) A smoke or fire detection system compliant with Sec. Sec.
25.858 and 25.855 must be provided that will detect fire/smoke within
each electrical/electronic equipment bay.
(b) Each system must provide a visual indication to the flight deck
within one minute after the start of a fire in an electrical/electronic
equipment bay.
(c) Airplane flight tests must be conducted to show compliance with
these requirements, and the performance of the smoke or fire detectors
must be shown in accordance with guidance provided in the latest
version of Advisory Circular 25-9, or other means acceptable to the
FAA.
(d) A procedure to shut down all non-essential systems in the
electrical/electronic equipment bays following a smoke detection in any
electrical/electronic equipment bay must be included in the Airplane
Flight Manual.
Issued in Renton, Washington, on July 22, 2008.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-17756 Filed 8-1-08; 8:45 am]
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