Rule2023-06395
Special Conditions: The Boeing Company Model 777-9 Airplane; Installation of Large Non-Structural Glass in the Passenger Compartment
Primary source
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Published
March 29, 2023
Effective
March 29, 2023
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
These special conditions are issued for the The Boeing Company (Boeing) Model 777-9 series airplane. This airplane will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is the installation of large, non- structural glass in the passenger cabin. 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.
Full Text
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<title>Federal Register, Volume 88 Issue 60 (Wednesday, March 29, 2023)</title>
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[Federal Register Volume 88, Number 60 (Wednesday, March 29, 2023)]
[Rules and Regulations]
[Pages 18389-18391]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-06395]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2023-0137; Special Conditions No. 25-836-SC]
Special Conditions: The Boeing Company Model 777-9 Airplane;
Installation of Large Non-Structural Glass in the Passenger Compartment
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for the The Boeing Company
(Boeing) Model 777-9 series airplane. This airplane will have a novel
or unusual design feature when compared to the state of technology
envisioned in the airworthiness standards for transport-category
airplanes. This design feature is the installation of large, non-
structural glass in the passenger cabin. 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: This action is effective on Boeing on March 29, 2023. Send
comments on or before May 15, 2023.
ADDRESSES: Send comments identified by Docket No. FAA-2023-0137 using
any of the following methods:
<bullet> Federal eRegulations Portal: Go to <a href="https://www.regulations.gov/">https://www.regulations.gov/</a> and follow the online instructions for sending
your comments electronically.
<bullet> 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.
<bullet> 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.
<bullet> Fax: Fax comments to Docket Operations at 202-493-2251.
Privacy: Except for Confidential Business Information (CBI) as
described in the following paragraph, and other information as
described in title 14, Code of Federal Regulations (14 CFR), Sec.
11.35, the FAA will post all comments
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received without change to <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>, including any
personal information you provide. The FAA will also post a report
summarizing each substantive verbal contact received about these
special conditions.
Confidential Business Information: Confidential Business
Information (CBI) is commercial or financial information that is both
customarily and actually treated as private by its owner. Under the
Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from
public disclosure. If your comments responsive to these special
conditions contain commercial or financial information that is
customarily treated as private, that you actually treat as private, and
that is relevant or responsive to these special conditions, it is
important that you clearly designate the submitted comments as CBI.
Please mark each page of your submission containing CBI as ``PROPIN.''
The FAA will treat such marked submissions as confidential under the
FOIA, and the indicated comments will not be placed in the public
docket of these special conditions. Send submissions containing CBI to
the individual listed in the FOR FURTHER INFORMATION CONTACT section
below. Comments the FAA receives, which are not specifically designated
as CBI, will be placed in the public docket for these special
conditions.
Docket: Background documents or comments received may be read at
<a href="https://www.regulations.gov/">https://www.regulations.gov/</a> 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: Shannon Lennon, Human Machine
Interface Section, AIR-626, Transport Standards Branch, Policy and
Innovation Division, Aircraft Certification Service, Federal Aviation
Administration, 2200 South 216th Street, Des Moines, Washington 98198;
telephone and fax 206-231-3209; email <a href="/cdn-cgi/l/email-protection#c291aaa3acacadacec8ea7acacadac82a4a3a3eca5adb4"><span class="__cf_email__" data-cfemail="f3a09b929d9d9c9dddbf969d9d9c9db3959292dd949c85">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: The substance of these special conditions
has been published in the Federal Register for public comment in
several prior instances with no substantive comments received.
Therefore, the FAA finds, pursuant to 14 CFR 11.38(b), that new
comments are unlikely, and notice and comment prior to this publication
are unnecessary.
Comments Invited
The FAA invites 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.
The FAA will consider all comments received by the closing date for
comments, and will consider comments filed late if it is possible to do
so without incurring delay. The FAA may change these special conditions
based on the comments received.
Background
On August 19, 2022, Boeing applied for an amendment to Type
Certificate No. T00001SE to include the new Model 777-9 series
airplane. The Boeing Model 777-9 series airplane, which is a derivative
of the Model 777-300ER currently approved under Type Certificate No.
T00001SE, is a twin-engine, transport category airplane, with capacity
for 495 passengers, and a maximum takeoff weight of 775,000 pounds.
Type Certification Basis
Under the provisions of title 14, Code of Federal Regulations (14
CFR), Sec. 21.101, Boeing must show that the Model 777-9 airplane
meets the applicable provisions of the regulations listed in Type
Certificate No. T00001SE, or the applicable regulations in effect on
the date of application for the change, except for earlier amendments
as agreed upon by the FAA.
If the Administrator finds that the applicable airworthiness
regulations (e.g., 14 CFR part 25) do not contain adequate or
appropriate safety standards for the Boeing Model 777-9 series airplane
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 feature, or should any other model already included on
the same type certificate be modified to incorporate the same novel or
unusual design feature, 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 Boeing Model 777-9 series airplane 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 Boeing Model 777-9 series airplane will incorporate the
following novel or unusual design feature:
This design feature is the installation of large, non-structural
glass in the passenger cabin. Possible installations of large non-
structural glass items include, but are not limited to, the following
items:
<bullet> Glass partitions
<bullet> Glass floor installations
<bullet> Glass attached to the ceiling
<bullet> Glass parts integrated in the stairway
<bullet> Wall or Door mounted mirrors and glass panels
<bullet> Mirrors as part of a door blow out panel
<bullet> Glass plate installed in a doorframe
<bullet> Washstand with glass-panel
The installation of these glass items in the passenger compartment,
which can be occupied during taxi, take-off and landing (TT&L), is a
novel or unusual design feature with respect to the installed material.
The applicable airworthiness regulations do not contain adequate or
appropriate safety standards for these design features.
Discussion
The use of glass results in trade-offs between the one unique
characteristic of glass--its capability for undistorted or controlled
light transmittance, or transparency--and the negative aspects of the
material. Glass, in its basic form as annealed, untreated sheet, plate,
or float glass, when compared to metals, is extremely notch-sensitive,
has a low fracture resistance, has a low modulus of elasticity, and can
be highly variable in its properties. While reasonably strong, it is
nonetheless not a desirable material for traditional airplane
applications because it is heavy (about the same density as aluminum),
and when it fails, it breaks into extremely sharp fragments that have
the potential for injury, and which have been known to be lethal. Thus,
the use of glass traditionally was limited to windshields, and
instrument or display transparencies. The regulations in 14 CFR 25.775
only address, and likewise only recognize, the unique use of glass in
windshield or window applications where no other material will serve.
This
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regulation does address the adverse properties of glass, but pilots
occasionally are injured from shattered glass windshields.
The FAA divides other uses of glass in the passenger cabin into
four groups. These groups were created to address the practical and
functional uses of glass. The four groups are as follows:
The first group is glass items installed in rooms or areas in the
cabin that are not occupied during taxi, takeoff, and landing (TT&L),
and a person does not have to enter or pass through the room or area to
get to any emergency exit.
The second group is glass integrated into a functional device the
operation of which is dependent upon the characteristics of glass, such
as instrument or indicator protective transparencies, or monitor
screens such as liquid crystal displays or plasma displays. This group
may be installed in any area in the cabin regardless of occupancy
during TT&L. Acceptable means of compliance for these items may depend
on the size and specific location of the device containing the glass.
The third group is small glass items installed in occupied rooms or
areas during TT&L, or rooms or areas that a person does not have to
enter or pass through to get to any emergency exit. The FAA defines a
small glass item as less than 8.8 lbs (4 kg) in mass.
The fourth group is large glass items, the subject of these special
conditions, installed in occupied rooms or areas during TT&L, or rooms
or areas that a person must enter or pass through to get to any
emergency exit. A large glass item is defined as 8.8 lbs (4 kg) or
greater in mass. Groups of glass items that collectively weigh 4 kg or
more would also be included. The mass is based on the amount of glass
that becomes hazardous in high inertial loads.
The glass items in groups one, two, and three are restricted to
applications where the potential for injury is either highly localized,
such as flight-instrument faces, or the location is such that injury
due to failure of the glass is unlikely, for example mirrors in
lavatories, because these installations necessitate the use of glass.
These glass items typically are addressed in a method-of-compliance
issue paper for each project based on existing part 25 regulations, or
in established policy. These issue papers identify specific tests that
could include abuse loading and ball-impact testing. In addition, these
items are subject to the inertia loads contained in Sec. 25.561, and
maximum positive-differential pressure for items like video monitors to
meet Sec. 25.789.
The items in group four are much larger and heavier than previously
approved, and raise additional safety concerns. These large, heavy
glass panels, primarily installed as architectural features, were not
envisioned in the regulations. The unique aspects of glass, with the
potential to become highly injurious or lethal objects during emergency
landing, minor crash conditions, or in flight, warrant a unique
approach to certification that addresses the characteristics of glass
that prevented its use in the past. These special conditions were
developed to ensure that airplanes with large glass features in
passenger cabins provide the same level of safety as airplanes using
traditional, lightweight materials. The FAA reiterates this intention
in the text of the special conditions by qualifying their use for group
four glass items.
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
Boeing Model 777-9 airplane. Should the type certificate for that model
be amended later to include any other model that incorporates the same
novel or unusual design feature, or should any other model already
included on the same type certificate be modified to incorporate the
same novel or unusual design feature, these special conditions would
apply to the other model as well.
Conclusion
This action affects only a certain novel or unusual design feature
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.
Authority Citation
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(f), 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 Boeing Company Model 777-9 series
airplanes.
For large glass items (a single item, or a collective group of
glass items, that weigh 4 kg or more in mass) installed in passenger-
occupied rooms or areas during taxi, takeoff, and landing, or installed
in rooms or areas that occupants must enter or pass through to access
any emergency exit, the glass installations on the Boeing Model 777-9
series airplanes must meet the following conditions:
1. Material Fragmentation--The glass used must be tempered or
otherwise treated to ensure that when fractured, it breaks into small
pieces with relatively dull edges. The glass component installation
must retain all glass fragments to minimize the danger from flying
glass shards or pieces. The applicant must demonstrate this by impact
and puncture testing and testing to failure.
2. Strength--The glass component must be strong enough to meet the
load requirements for all flight and landing loads, including any of
the applicable emergency landing conditions in subparts C & D of 14 CFR
part 25. In addition, glass components that are located such that they
are not protected from contact with cabin occupants must not fail due
to abusive loading, such as impact from occupants stumbling into,
leaning against, sitting on, or performing other intentional or
unintentional forceful contact. The effect of design details such as
geometric discontinuities or surface finish e.g., embossing, etching,
etc., must be assessed.
3. Retention--The glass component, as installed in the airplane,
must not come free of its restraint or mounting system in the event of
an emergency landing. Both the directional loading and rebound
conditions must be assessed. The effect of design details such as
geometric discontinuities or surface finish e.g., embossing, etching,
etc., must be assessed.
4. Instructions for Continued Airworthiness--The instructions for
continued airworthiness must reflect the fastening method used and must
ensure the reliability of the methods used (e.g., life limit of
adhesives, or clamp connection). Inspection methods and intervals must
be defined based upon adhesion data from the manufacturer of the
adhesive or actual adhesion test data, if necessary.
Issued in Washington, DC, on date March 23, 2023.
Gregg Nesemeier, III,
Acting Manager, Technical Innovation Policy Branch, Policy and
Innovation Division, Aircraft Certification Service.
[FR Doc. 2023-06395 Filed 3-28-23; 8:45 am]
BILLING CODE 4910-13-P
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