[Federal Register Volume 81, Number 200 (Monday, October 17, 2016)]
[Rules and Regulations]
[Pages 71357-71360]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-25060]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2016-9282; Special Conditions No. 25-640-SC]
Special Conditions: Embraer S.A., Model ERJ 190-300 Series
Airplanes; Electrical/Electronic Equipment Bay Fire Detection and Smoke
Penetration
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for the Embraer S.A. Model
ERJ 190-300 series airplanes. These airplanes will have novel or
unusual design features when compared to the
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state of technology envisioned in the airworthiness standards for
transport category airplanes. These design features are electrical/
electronic equipment bays distributed throughout the airplane, with
three of them in the pressurized area. The time it takes to determine
the source of smoke in an airplane with three or more equipment bays
could allow fire to spread, generating a significant quantity of smoke
and damage. The applicable airworthiness regulations do not contain
adequate or appropriate safety standards for these design features.
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: This action is effective on Embraer S.A. on October 17, 2016. We
must receive your comments by December 1, 2016.
ADDRESSES: Send comments identified by docket number FAA-2016-9282
using any of the following methods:
Federal eRegulations Portal: Go to http://www.regulations.gov/and follow the online instructions for sending your
comments electronically.
Mail: Send comments to Docket Operations, M-30, U.S.
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
Hand Delivery or Courier: Take comments to Docket
Operations in Room W12-140 of the West Building Ground Floor at 1200
New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
Fax: Fax comments to Docket Operations at 202-493-2251.
Privacy: The FAA will post all comments it receives, without
change, to http://www.regulations.gov/, including any personal
information the commenter provides. Using the search function of the
docket Web site, anyone can find and read the electronic form of all
comments received into any FAA docket, including the name of the
individual sending the comment (or signing the comment for an
association, business, labor union, etc.). DOT's complete Privacy Act
Statement can be found in the Federal Register published on April 11,
2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov/.
Docket: Background documents or comments received may be read at
http://www.regulations.gov/ at any time. Follow the online instructions
for accessing the docket or go to Docket Operations in Room W12-140 of
the West Building Ground Floor at 1200 New Jersey Avenue SE.,
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays.
FOR FURTHER INFORMATION CONTACT: Stephen Happenny, FAA, Propulsion and
Mechanical Systems Branch, ANM-112, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind Avenue SW., Renton,
Washington 98057-3356; telephone 425-227-2147; facsimile 425-227-1149.
SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and
opportunity for prior public comment on, these special conditions is
impracticable because these procedures would significantly delay
issuance of the design approval and thus delivery of the affected
airplane.
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
publication in the Federal Register.
Comments Invited
The FAA is requesting comments to allow interested persons to
submit views that may not have been submitted in response to the prior
opportunities for comment described above. 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 will consider all comments we receive by the closing date for
comments. We may change these special conditions based on the comments
we receive.
Background
On September 13, 2013, Embraer S.A. applied for an amendment to
Type Certificate (TC) No. A57NM to include the new Model ERJ 190-300
series airplanes. The ERJ 190-300, which is a derivative of the ERJ
190-100 STD currently approved under TC No. A57NM, is a 97 to 114-
passenger transport category airplane with two Pratt & Whitney Model
PW1900G engines, a new wing design with a high aspect ratio and raked
wingtip, and a new electrical distribution system.
The ERJ 190-300 will have electrical/electronic equipment bays
distributed throughout the airplane, with three of them in the
pressurized area. The applicable airworthiness requirements of Title
14, Code of Federal Aviation (14 CFR) 25.831 and 25.869 do not contain
adequate or appropriate safety standards regarding smoke or fire
detection and protection against the penetration of hazardous
quantities of smoke into occupied areas of the airplane for this type
of airplane configuration.
Type Certification Basis
Under the provisions of 14 CFR 21.101, Embraer S.A. must show that
the ERJ 190-300 meets the applicable provisions of the regulations
listed in TC No. A57NM or the applicable regulations in effect on the
date of application for the change, except for earlier amendments as
agreed upon by the FAA. Embraer S.A. must show that the ERJ 190-300
meets the applicable provisions of 14 CFR part 25, as amended by
Amendments 25-1 through 25-137.
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 25) do not contain adequate or
appropriate safety standards for the ERJ 190-300 because of a novel or
unusual design feature, special conditions are prescribed under the
provisions of Sec. 21.16.
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 features, or should any other model already included on
the same type certificate be modified to incorporate the same novel or
unusual design features, these special conditions would also apply to
the other model under Sec. 21.101.
In addition to the applicable airworthiness regulations and special
conditions, the ERJ 190-300 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 14 CFR 11.19, in
accordance with Sec. 11.38, and they become part of the type
certification basis under Sec. 21.101.
Novel or Unusual Design Features
The ERJ 190-300 will incorporate the following novel or unusual
design features: Electrical/electronic equipment bays that are
distributed throughout the airplane. There are three electrical bays in
the pressurized area--forward, center, and aft. The forward bay is
located below the flight deck; the center bay is in the center fuselage
below the
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cabin floor; and the aft bay is located near the aft pressure bulkhead.
Discussion
Traditionally, airplanes certified under part 25 have had one or
two electrical equipment bays located in the lower lobe adjacent to
pressure regulator and outflow valves or vents. If a fire occurs in an
electrical/electronic equipment bay, any smoke is drawn toward the
outflow valves or vents and discharged from the airplane without
entering occupied areas. On these airplanes, the procedure for flight
crew determination of whether the source of the smoke is in the
electrical/electronic equipment bay has relied on trial and error.
However, many factors, including the airflow pattern, potential leak
paths, and location of outflow and regulator valves, can make it
difficult to identify the smoke source, especially during system and
flight transients, such as climbing, descending, or other changes that
would affect the internal flow path. Also, if smoke penetrates occupied
areas, the flight crew would have less information with which to
determine whether the source of the smoke is in an electrical/
electronic equipment bay.
The FAA has accepted this trial and error approach for airplanes
with no more than two electrical/electronic equipment bays, both
located in the lower lobe. However, for airplanes with three or more
equipment bays, the additional time it could take the flightcrew to
determine the source of smoke would also allow the fire additional time
to spread and generate significant amounts of smoke and damage.
Section 25.857 requires that cargo compartments have means to
prevent hazardous quantities of smoke or fire extinguishing agent from
penetrating into occupied areas of the airplane. However, the
regulatory requirements do not 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.
The FAA determined that airplanes with electrical/electronic
equipment bay configurations like that of the ERJ 190-300 need a means
to detect smoke or fire in each electrical/electronic equipment bay
located in the pressurized cabin to ensure that the flightcrew can make
an informed decision as to the source of smoke and shut down the
specific electrical/electronic equipment where smoke or fire is
present. If the electrical/electronic equipment cannot be completely
shut down due to conflict with other safety requirements, Embraer must
conduct an analysis to:
Show the criteria for shutting down the specific
electrical/electronic equipment in the electrical/electronic equipment
bay that can be shut down; and
For the remaining electrical/electronic equipment,
demonstrate that there are safety precautions incorporated against fire
propagation, such as thermal protection, fire containment, or other
means, as addressed in advisory circular AC 25-16, ``Electrical Fault
and Fire Prevention and Protection,'' dated April 5, 1991.
The purpose of the smoke/fire detection systems is to accomplish
one or more of the following: Automatically shut off power to the
affected equipment; reconfigure the environmental control systems, if
necessary, to control any smoke resulting from a fire or overheat
condition; or alert the crew to the existence of the fire.
These alternate criteria that the FAA has developed to certify
airplane designs that incorporate distributed electrical/electronic
equipment bays are based on existing smoke/fire detection and smoke
penetration guidance and acceptable past practices. Sections 25.831(b),
(c), and (d), and 25.869 provide the general requirements that apply to
electrical/electronic equipment smoke penetration and evacuation.
Flight tests are conducted to demonstrate compliance; however, the
amount of smoke generated and flight test conditions have been highly
variable.
The special conditions below require a smoke or fire detection
system in each electrical/electronic equipment bay located in the
pressurized compartment. They also include requirements to prevent
propagation of hazardous quantities of smoke or fire extinguishing
agent throughout the passenger cabin.
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.
Applicability
As discussed above, these special conditions are applicable to the
ERJ 190-300 series airplanes. Should Embraer S.A. apply at a later date
for a change to the type certificate to include another model
incorporating the same novel or unusual design feature, these special
conditions would apply to that model as well.
Conclusion
This action affects only certain novel or unusual design features
on one model series of 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
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 the Embraer S.A. Model ERJ 190-300
series airplanes.
Design Requirements for Smoke Detection and Smoke Penetration in
Distributed Electrical/Electronic Equipment Bays.
1. Requirements to prevent propagation of smoke from entering the
passenger cabin and cockpit:
a. To prevent such propagation, means to prevent hazardous
quantities of smoke originating from the electrical/electronic
equipment bays from incapacitating passengers and crew must be
demonstrated. Flight tests must be part of such demonstration and shall
cover all dispatchable system configurations.
b. A small quantity of smoke may enter an occupied area only if the
design meets all of the following conditions:
i. The smoke enters occupied areas during system transients \1\
from below deck or main deck sources. 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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ii. Penetration of the small quantity of smoke is a dynamic event,
characterized by 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
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would indicate that the ventilation system is failing to meet the
requirements of 14 CFR 25.831(b).
iii. The smoke from a smoke source below the main deck must not
rise above armrest height on the main deck.
iv. The smoke from a source in the main deck must dissipate rapidly
via dilution with fresh air and be evacuated from the airplane. A
procedure must be included in the Airplane Flight Manual (AFM) 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 that simulates the emergency procedures used in the event of
a fire/smoke 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 smoke or fire detection in electrical/electronic
equipment bays:
A smoke or fire detection system compliant with 14 CFR 25.858 and
25.855 must be provided for each electrical/electronic equipment bay in
the pressurized cabin. Each system must provide a visual indication to
the flight deck within one minute after the start of a fire. Airplane
flight tests must be conducted to show compliance with these
requirements, and the performance of the detectors must be shown in
accordance with AC 25-9A, ``Smoke Detection, Penetration, and
Evacuation Tests and Related Flight Manual Emergency Procedures,'' or
other means acceptable to the FAA.
3. Requirement for AFM procedures safety evaluation:
It shall be demonstrated by means of flight tests that, in the
event of smoke/fire detection in the electrical/electronic equipment
bays, the AFM procedures for shutting down any or all of the
electrical/electronic equipment do not compromise the safe operation of
the airplane.
In case a procedure requests only part of the equipment to be shut
down, the remaining equipment shall be incorporated with safety
features against fire propagation.
Issued in Renton, Washington, on October 4, 2016.
Michael Kaszycki,
Assistant Manager, Transport Airplane Directorate, Aircraft
Certification Service.
[FR Doc. 2016-25060 Filed 10-14-16; 8:45 am]
BILLING CODE 4910-13-P