[Federal Register Volume 89, Number 20 (Tuesday, January 30, 2024)]
[Rules and Regulations]
[Pages 5763-5765]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-01739]



[[Page 5763]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2023-2438; Special Conditions No. 25-848-SC]


Special Conditions: Gulfstream Aerospace Corporation Model GVIII-
G700 and GVIII-G800 Series Airplanes; Installation of Large Non-
Structural Glass in the Passenger Compartment

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comment.

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SUMMARY: These special conditions are issued for the Gulfstream 
Aerospace Corporation (Gulfstream) Model GVIII-G700 and GVIII-G800 
series airplanes. These airplanes 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 items 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 Gulfstream on January 30, 2024. Send 
comments on or before March 15, 2024.

ADDRESSES: Send comments identified by Docket No. FAA-2023-2438 using 
any of the following methods:
    Federal eRegulations Portal: Go to 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.
    Docket: Background documents or comments received may be read at 
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: Myra Kuck, Cabin Safety, routing 
symbol AIR-624, Technical Policy Branch, Policy and Standards Division, 
Aircraft Certification Service, Federal Aviation Administration, 3960 
Paramount Blvd., Lakewood, CA 90712; telephone and fax 405-666-1059; 
email [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    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 138(b), that new comments are unlikely, and notice and comment 
prior to this publication are unnecessary.

Privacy

    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in title 14 
CFR 11.35, the FAA will post all comments received without change to 
www.regulations.gov, 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 above. Comments the FAA receives, which are 
not specifically designated as CBI, will be placed in the public docket 
for these special conditions.

Background

    On December 31, 2019, Gulfstream applied for an amendment to Type 
Certificate No. T00015AT to include the new Model GVIII-G700 and GVIII-
G800 series airplanes. These airplanes, which are derivatives of the 
Model GVI currently approved under Type Certificate No. T00015AT, are 
twin-engine, transport-category airplanes, with maximum seating for 19 
passengers, and a maximum take-off weight of 107,600 pounds (GVIII-
G700) and 105,600 pounds (GVIII-G800).

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, Gulfstream must show that the Model GVIII-G700 and GVIII-
G800 series airplanes meet the applicable provisions of the regulations 
listed in Type Certificate No. T00015AT, 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 Gulfstream Model GVIII-G700 and 
GVIII-G800 series airplanes 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 Gulfstream Model GVIII-G700 and GVIII-G800 series 
airplanes must comply with the 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 14 CFR 11.38, and they become part of the type 
certification basis under Sec.  21.101.

Novel or Unusual Design Features

    The Gulfstream Model GVIII-G700 and GVIII-G800 airplanes will

[[Page 5764]]

incorporate the following novel or unusual design feature:
    Installation of large, non-structural glass items in the passenger 
cabin. Possible installations of large non-structural glass items 
include, but are not limited to, the following items:

 Glass partitions
 Glass floor installations
 Glass attached to the ceiling
 Glass parts integrated in the stairway
 Wall or Door mounted mirrors and glass panels
 Mirrors as part of a door blow out panel
 Glass plate installed in a doorframe
 Washstand with glass-panel
 Mirrored bulkheads
 Partial partitions with transparent glass decorative features

    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 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 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:
    1. 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.
    2. The second group is glass integrated into a functional device 
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.
    3. 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 (4kg) in mass.
    4. 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 an 
emergency exit. A large glass item is defined as 8.8 lbs (4kg) and 
greater in mass. Groups of glass items that collectively weigh 4kg 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 have been 
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 
Gulfstream Model GVIII-G700 and GVIII-G800 series airplanes. Should 
Gulfstream apply at a later date for a change to the type certificate 
to include another 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 Gulfstream Model GVIII-G700 and GVIII-G800 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, and 
44704.

The Special Conditions

    [ssquf] 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 Gulfstream Model GVIII-G700 and 
GVIII-G800 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

[[Page 5765]]

access any emergency exit, the glass installations on the Gulfstream 
Model GVIII-G700 and GVIII-G800 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 in Kansas City, Missouri, on January 24, 2024.
Patrick R. Mullen,
Manager, Technical Policy Branch, Policy and Standards Division, 
Aircraft Certification Service.
[FR Doc. 2024-01739 Filed 1-29-24; 8:45 am]
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