[Federal Register: November 30, 2006 (Volume 71, Number 230)]
[Rules and Regulations]
[Page 69186-69190]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr30no06-3]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM354; Special Conditions No. 25-336-SC]
Special Conditions: Boeing Commercial Airplane Group, Boeing
Model 777 Series Airplane; Overhead Cross Aisle Stowage Compartments
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
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SUMMARY: These special conditions are issued for the Boeing Model 777
series airplanes. This airplane will have novel or unusual design
features associated with overhead cross aisle stowage compartments. The
applicable airworthiness regulations do not contain adequate or
appropriate safety standards for these design features. These special
conditions contain the additional safety standards the Administrator
considers necessary to establish a level of safety equivalent to that
established by the existing airworthiness standards.
EFFECTIVE DATE: November 15, 2006.
FOR FURTHER INFORMATION CONTACT: Jayson Claar, FAA, Airframe/Cabin
Branch, ANM-115, Transport Airplane Directorate, Aircraft Certification
Service, 1601 Lind Avenue SW., Renton, Washington, 98057-3356;
telephone (425) 227-2194; facsimile (425) 227-1232.
SUPPLEMENTARY INFORMATION:
Background
On April 20, 2005, Boeing Commercial Airplane Group, Seattle,
Washington, applied for a supplemental type certificate to permit
installation of overhead cross aisle stowage compartments in Boeing 777
series airplanes. The Boeing Model 777 series airplanes are large twin
engine airplanes with four or five pairs of Type A exits. The Boeing
777 airplanes can be configured with various passenger capacities and
ranges.
The regulations do not address the novel and unusual design
features associated with the installation of overhead cross aisle
stowage compartments installed on the Boeing Model 777, making these
special conditions necessary. Generally, the requirements for overhead
stowage compartments are similar to stowage compartments in remote crew
rest compartments (i.e., located on lower lobe, main deck or overhead)
already in use on Boeing Model 777 and 747 series
[[Page 69187]]
airplanes. Remote crew rest compartments have been previously installed
and certified in the main passenger cabin area, above the main
passenger area, and below the passenger cabin area adjacent to the
cargo compartment of the Boeing Model 777-200, and -300 series
airplanes.
Type Certification Basis
Under the provisions of Sec. 21.101, Boeing Commercial Airplane
Group must show that the Boeing Model 777, as changed, continues to
meet the applicable provisions of the regulations incorporated by
reference in Type Certificate No. T00001SE or the applicable
regulations in effect on the date of application for the change. The
regulations incorporated by reference in the type certificate are
commonly referred to as the ``original type certification basis.'' The
regulations incorporated by reference in Type Certificate No. T00001SE
for the Boeing Model 777 series airplanes include Title 14 Code of
Federal Regulations (CFR), part 25, as amended by Amendments 25-1
through 25-100, with exceptions, for various models. Refer to Type
Certificate No. T00001SE, as applicable, for a complete description of
the certification basis for this model, including certain special
conditions that are not relevant to these special conditions.
If the Administrator finds the applicable airworthiness regulations
(part 25 as amended) do not contain adequate or appropriate safety
standards for the Boeing Model 777 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 Boeing Model 777 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 applicant apply for a change to modify any
other model included on the same type certificate 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 Boeing Model 777 will incorporate the following novel or
unusual design features: the installation of powered lift-enabled
stowage compartments that rise into the overhead area and lower into
the cabin.
The overhead cross aisle stowage compartments are configured to
allow stowage of galley type standard containers as well as coats,
bags, and other items typically stowed in closets or bins. These
stowage compartments may be located above the emergency exit cross
aisles of Boeing Model 777 series airplanes. Because the compartment is
lowered into the main cabin, it could affect egress if it cannot be
raised again. The overhead compartment may lower into a cross aisle as
defined in Sec. 25.813, but it may also lower into other potential
egress paths. For the purposes of these special conditions, the same
criteria apply, whether or not the egress path is required by Sec.
25.813. Therefore, as used in these special conditions, the term
``overhead cross aisle stowage compartment'' addresses all such
compartments.
Each stowage compartment is accessed from the main deck by a
powered lift that lowers and raises the stowage compartment between the
overhead and the main deck. In addition, the lift can be hand cranked
down and up in the event of a power or lift motor failure. A smoke
detection system will be provided in the overhead cross aisle stowage
compartments.
Discussion of the Special Conditions
In general, the requirements listed in these special conditions for
overhead cross aisle stowage compartments are similar to those
previously approved for overhead crew rest compartments in earlier
certification programs, such as for the Boeing Model 777 and Model 747
series airplanes. These special conditions establish compartment
access, power lift, electrical power, smoke/fire detection, fire
extinguisher, fire containment, smoke penetration, and compartment
design criteria for the overhead cross aisle stowage compartments. The
overhead stowage compartments are not a direct analogy to stowage
compartments in remote crew rest compartments installed and certified
for Boeing Model 777 series airplanes, but the safety issues raised are
similar. Features similar to those considered in the development of
previous special conditions for fire protection will be included here
also. The requirements provide an equivalent level of safety to that
provided by other Boeing Model 777 series airplanes with similar
overhead compartments.
Operational Evaluations and Approval
The FAA's Aircraft Certification Service will administer these
special conditions, which specify requirements for design approvals
(that is, type design changes and supplemental type certificates) of
overhead cross aisle stowage compartments.
The Aircraft Evaluation Group of the FAA's Flight Standards Service
must evaluate and approve the operational use of overhead cross aisle
stowage compartments prior to use. The Aircraft Evaluation Group must
receive all instructions for continued airworthiness, including service
bulletins, prior to the FAA accepting and issuing approval of the
modification.
Special Condition No. 1, Compartment Access and Placards
Appropriate placards, or other means, are required to address door
access and locking to prohibit or prevent passenger access, and
operation of the overhead storage compartment. There must also be a
means to preclude anyone from being trapped inside the stowage
compartment, if it is large enough for a person to enter. If there is
more than one door providing access, each door must be equipped with
these means.
Special Condition No. 2, Power Lift
The power lift must be designed so the overhead stowage compartment
will not jam in the down position, even if lowered on top of a hard
structure. The lift must operate at a speed, and stop above the floor
at such a height, that allows anyone underneath the compartment to move
clear without injury. The lift controls must be placed clear of the
compartment door and must be pressed continuously for lift operation.
Training on power lift operation procedures must be added to
appropriate manuals.
Special Condition No. 3, Manual Operation
There must be a means to manually operate the lift that is
independent of the electrical drive system. The lift must be operable
by a range of occupants, including a fifth percentile female. The
manual means must be capable of lowering the overhead stowage
compartment quickly to the main deck to fight a fire. The manual system
must be capable of raising the compartment quickly so the cross aisle
or other egress path (if applicable) is not blocked in an emergency. If
electrical or manual power is removed, there must be a means, such as a
brake, to prevent the compartment from unrestricted movement, i.e.,
falling. Training on
[[Page 69188]]
manual operation procedures must be added to appropriate manuals.
Special Condition No. 4, Handheld Fire Extinguisher
For compartments larger than 25 cubic feet, a handheld fire
extinguisher appropriate to fight the kinds of fire likely to occur in
the overhead stowage compartment must be provided. This handheld fire
extinguisher must be adjacent to the overhead compartment. This
extinguisher must be in addition to those required for the passenger
cabin.
Special Condition No. 5, Fire Containment
This special condition requires either the installation of a
manually activated fire extinguishing system that is accessible from
outside the overhead stowage compartment, or a demonstration that the
crew could satisfactorily perform the function of extinguishing a fire
under the prescribed conditions. A manually activated built-in fire
extinguishing system would be required only if a crewmember could not
successfully locate and get access to the fire during a demonstration
where the crewmember is responding to the alarm. For the duration of
the flight, the system must have adequate capacity to suppress any fire
occurring in the stowage compartment considering the fire threat,
volume of the compartment, and the ventilation rate.
Special Condition No. 6, Smoke Penetration
The design of the compartment must provide means to exclude
hazardous quantities of smoke or extinguishing agent originating in the
compartment from entering other occupied areas. The means must take
into account the time period during which the compartment may be
accessed to manually fight a fire, if applicable.
Smoke entering any other compartment occupied by crewmembers or
passengers, when access to the stowage compartment is opened to
manually fight a fire, must dissipate within five minutes after the
access to the stowage compartment is closed.
During the one-minute smoke detection time (see Special Condition
No. 7), penetration of a small quantity of smoke (one that would
dissipate within 3 minutes under normal ventilation conditions) from
this overhead stowage compartment into an occupied area on this
airplane configuration would be acceptable based on the limitations
placed in this and other associated special conditions. These special
conditions place sufficient restrictions in the quantity and type of
material allowed in the overhead stowage compartment that threat from a
fire in this remote area would be equivalent to that experienced on the
main cabin.
If a built-in fire extinguishing system is used in lieu of manual
fire fighting, then the fire extinguishing system must be designed so
that no hazardous quantities of extinguishing agent will enter other
compartments occupied by passengers or crew.
Special Condition No. 7, Compartment Design Criteria
The material used to construct the overhead stowage compartment
must meet the flammability requirements for compartment interiors in
Sec. 25.853 and be fire resistant. Depending on the size of the
compartment, certain fire protection features of Class B cargo
compartments are also required. Enclosed stowage compartments equal to
or exceeding 25 ft\3\ in interior volume must be provided with a smoke
or fire detection system to ensure that a fire can be detected within a
one-minute detection time. This is the same requirement as has been
applied to remote crew rest compartments.
Enclosed stowage compartments equal to or greater than 57 ft\3\ in
interior volume but less than or equal to 200 ft\3\, must have a liner
that meets the requirements of Sec. 25.855 for a Class B cargo
compartment. The overhead stowage compartment may not be greater than
200 ft\3\ in interior volume. The in-flight accessibility of very large
enclosed stowage compartments and the subsequent impact on the
crewmember's ability to effectively reach any part of the compartment
with the contents of a handheld fire extinguisher would require
additional fire protection considerations similar to those required for
inaccessible compartments such as Class C cargo compartments.
The overhead stowage compartment smoke or fire detection and fire
suppression systems (including airflow management features which
prevent hazardous quantities of smoke or fire extinguishing agent from
entering any other compartment occupied by crewmembers or passengers)
is considered complex in terms of paragraph 6d of Advisory Circular
(AC) 25.1309-1A, ``System Design and Analysis.'' The FAA considers
failure of the overhead stowage compartment fire protection system
(that is, smoke or fire detection and fire suppression systems) in
conjunction with an overhead stowage fire to be a catastrophic event.
Based on the ``Depth of Analysis Flowchart'' shown in Figure 2 of AC
25.1309-1A, the depth of analysis should include both qualitative and
quantitative assessments (reference paragraphs 8d, 9, and 10 of AC
25.1309-1A).
The requirements to enable crewmember(s) quick access to the
overhead stowage compartment and to locate a fire source inherently
places limits on the amount of baggage stowed and the size of the
overhead stowage compartment. The overhead stowage compartment is
limited to stowage of galley type standard containers as well as coats,
bags, and other items typically stowed in closets or bins. It is not
intended to be used for the stowage of other items. The design of such
a system to include other items may require additional special
conditions to ensure safe operation.
Discussion of Comments
Notice of proposed special conditions No. 25-06-09-SC for the
Boeing Model 777-200 series airplanes was published in the Federal
Register on October 18, 2006 (71 FR 61432). An amended proposed notice
of special conditions No. SC-06-29A-SC for the Boeing Model 777 series
airplanes was published in the Federal Register on November 2, 2006 (71
FR 64478). No comments were received, and the special conditions are
adopted as proposed, except for clarifying changes.
Applicability
These special conditions are applicable to the Boeing Model 777
series airplanes with overhead cross aisle stowage compartments. Should
Boeing Commercial Airplane Group apply later for a change to Type
Certificate No. T00001SE 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.
Under standard practice, the effective date of final special
conditions would be 30 days after the date of publication in the
Federal Register, however, as the certification date for the Boeing 777
series is imminent, the FAA finds that good cause exists for make these
special conditions effective upon issuance.
Conclusion
This action affects only certain novel or unusual design features
on the Boeing Model 777 series airplanes. It is not a rule of general
applicability and affects only the applicant who applied to the FAA for
approval of these features on the airplane.
[[Page 69189]]
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 Boeing Model 777 series airplanes.
Each overhead cross aisle stowage compartment and the adjacent area,
including the structural frame, mechanical system and drive motor, must
meet the following requirements:
1. Compartment Access and Placards. There must be a means to
prohibit or prevent passengers from entering or operating the overhead
cross aisle stowage compartment. Placards prohibiting access are
acceptable. If a compartment is large enough for a person to enter,
there must be a means to preclude anyone from being trapped inside the
stowage compartment. If a latching/locking mechanism is installed, the
door must be capable of being opened from the outside without the aid
of special tools. The mechanism must not prevent opening from the
inside of the stowage at any time.
2. Power Lift. There must be a means such as a load or force
limiter to protect the overhead cross aisle stowage compartment power
lift from failure or jamming in the down position in the event it is
lowered on top of a hard structure such as a galley cart.
(a) The lift controls must be placed so the operator is clear of
the lift and designed such that the controls must be pressed
continuously for lift operation.
(b) The lift must raise and lower the stowage compartment at a slow
enough rate, and stop above the floor at such a height, that anyone
underneath can easily move clear without injury.
(c) Stowage compartment operation training procedures must be added
to the appropriate flight attendant manuals.
3. Manual Lift. There must be a means in the event of failure of
the aircraft's main power system, or of the powered overhead cross
aisle stowage compartment lift system, for manually activating the lift
system.
(a) This manual means must be independent of the electrical drive
system
(b) The manual means must be accessible and operable by a range of
occupants, including a fifth percentile female.
(c) The manual means must be capable of lowering the stowage
compartment to the main deck quickly enough to fight a fire in the
stowage compartment before overhead cross aisle stowage compartment
fire containment is compromised.
(d) The manual means must be capable of quickly raising the stowage
compartment such that the cross aisle, or other egress path is not
blocked in the event of an emergency.
(e) Stowage compartment firefighting training procedures must be
added to the appropriate manuals.
(f) The lift system must include a means, such as a brake, to
retain the overhead cross aisle stowage compartment in any position of
travel when the manual or electric drive force is removed.
4. Fire Extinguisher. The means to manually fight a fire in the
overhead cross aisle stowage compartment must consider the additional
stowage volume and time required to manually lower the compartment
after indication. For compartments larger than 25 ft\3\ the following
equipment must be provided directly adjacent to each overhead cross
aisle stowage compartment: at least one approved handheld fire
extinguisher, in addition to the fire extinguisher requirements of
Sec. 25.851 and Sec. 121.309, appropriate for the kinds of fires
likely to occur within the overhead stowage compartment.
5. Fire Containment. Fires originating within the overhead cross
aisle stowage compartment must be controlled for the duration of the
flight without a crewmember having to access the compartment.
Alternatively, the design of the access provisions must allow
crewmembers equipped for firefighting to have unrestricted access to
the compartment. If the latter approach is elected it must be
demonstrated that a crewmember has sufficient access to enable them to
extinguish a fire. The time for a crewmember on the main deck to react
to the fire alarm, (and, if applicable, to don the firefighting
equipment and to open the compartment) must not exceed the flammability
and fire containment capabilities of the stowage compartment.
6. Smoke Penetration. There must be a means provided to exclude
hazardous quantities of smoke or extinguishing agent originating in the
overhead cross aisle stowage compartment from entering any other
compartment occupied by crewmembers or passengers. If access is
required to comply with Special Condition No. 5, this means must
include the time period when accessing the stowage compartment to
manually fight a fire. Smoke entering any other compartment occupied by
crewmembers or passengers, when access to the stowage compartment is
opened to manually fight a fire, must dissipate within five minutes
after the access to the stowage compartment is closed. Prior to the one
minute smoke detection time (reference note 2 in paragraph (7))
penetration of a small quantity of smoke (one that would dissipate
within 3 minutes under normal ventilation conditions) from the stowage
compartment into an occupied area is acceptable. Flight tests must be
conducted to show compliance with this requirement.
7. Compartment Design Criteria. The overhead cross aisle stowage
compartment must be designed to minimize the hazards to the airplane in
the event of a fire originating in the stowage compartment.
(a) Fire Extinguishing System. If a built-in fire extinguishing
system is used in lieu of manual firefighting, then the fire
extinguishing system must be designed so no hazardous quantities of
extinguishing agent will enter other compartments occupied by
passengers or crew. The system must have adequate capacity to suppress
any fire occurring in the stowage compartment, considering the fire
threat, volume of the compartment, and the ventilation rate.
(b) Compartment Size. All overhead cross aisle stowage compartments
must meet the design criteria given in the table below. As indicated by
the table below, enclosed stowage compartments greater than 200 ft\3\
in interior volume are not addressed by this special condition.
Stowage Compartment Interior Volumes
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Fire protection features Less than 25 ft\3\ 25 ft\3\ to 57 ft\3\ 57 ft\3\ to 200 ft\3\
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Materials of Construction Yes....................... Yes....................... Yes.
\1\.
Detectors \2\............... No........................ Yes....................... Yes.
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Liner \3\................... No........................ Yes....................... Yes.
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\1\ Material
The material used to construct each enclosed stowage compartment must be at least fire resistant and must meet
the flammability standards established for interior components (that is, 14 CFR Part 25 Appendix F, Parts I,
IV, and V) per the requirements of Sec. 25.853. For compartments less than 25 ft\3\ in total interior
volume, the design must ensure the ability to contain a fire likely to occur within the compartment under
normal use.
\2\ Detectors
Enclosed stowage compartments equal to or exceeding 25 ft\3\ in total interior volume must be provided with a
smoke or fire detection system to ensure that a fire can be detected within one minute. Flight tests must be
conducted to show compliance with this requirement. Each system (or systems) must provide:
(a) A visual indication in the flight deck within one minute after the start of a fire;
(b) A warning in the main passenger cabin. This warning must be readily detectable by a flight attendant,
taking into consideration the positioning of flight attendants throughout the main passenger compartment
during various phases of flight.
\3\ Liner
If it can be shown the material used to construct the stowage compartment meets the flammability requirements
of a liner for a Class B cargo compartment (that is, Sec. 25.855 at Amendment 25-93 and Appendix F, part I,
paragraph (a)(2)(ii)), in addition to the above \1\ Material requirement, then no liner would be required for
enclosed stowage compartments equal to or greater than 25 ft\3\ in total interior volume but less than 57
ft\3\ in total interior volume. For all enclosed stowage compartments equal to or greater than 57 ft\3\ in
total interior volume but less than or equal to 200 ft\3\, a liner must be provided that meets the
requirements of Sec. 25.855 for a Class B cargo compartment.
Issued in Renton, Washington, on November 15, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E6-20277 Filed 11-29-06; 8:45 am]
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