[Federal Register Volume 70, Number 161 (Monday, August 22, 2005)]
[Rules and Regulations]
[Pages 48842-48844]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-16517]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM325; Special Conditions No. 25-294-SC]


Special Conditions: Gulfstream Model G150 Airplanes; Side-Facing 
Single-Occupant Seats

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for Gulfstream Model G150 
airplanes. These airplanes will have a novel or unusual design 
feature(s) associated with side-facing single-occupant seats. 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: The effective date of these special conditions is August 9, 
2005. Comments must be received on or before October 6, 2005.

ADDRESSES: Comments on these special conditions may be mailed in 
duplicate to: Federal Aviation Administration, Transport Airplane 
Directorate, Attn: Rules Docket (ANM-113), Docket No.

[[Page 48843]]

NM325, 1601 Lind Avenue SW., Renton, Washington, 98055-4056; or 
delivered in duplicate to the Transport Airplane Directorate at the 
above address. Comments must be marked: Docket No. NM325. Comments may 
be inspected in the Rules Docket weekdays, except Federal holidays, 
between 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: John A. Shelden, FAA, Airframe/Cabin 
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98055-
4056; telephone (425) 227-2785; facsimile (425) 227-1232.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice and 
opportunity for prior public comment hereon are impracticable because 
these procedures would significantly delay issuance of the approval 
design and thus delivery of the affected aircraft. 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 issuance.

Comments Invited

    Interested persons are invited to submit such written data, views, 
or arguments as they may desire. Communications should identify the 
rules docket number and be submitted in duplicate to the address 
specified above. The Administrator will consider all communications 
received on or before the closing date for comments. The special 
conditions may be changed in light of the comments received. All 
comments received will be available in the Rules Docket for examination 
by interested persons, both before and after the closing date for 
comments. A report summarizing each substantive public contact with FAA 
personnel concerning this rulemaking will be filed in the docket. 
Persons wishing the FAA to acknowledge receipt of their comments 
submitted in response to these special conditions must include with 
those comments a self-addressed, stamped postcard on which the 
following statement is made: ``Comments to Docket No. NM325.'' The 
postcard will be date stamped and returned to the commenter.

Background

    On September 22, 2002, Gulfstream Aerospace LP (GALP), Ben Gurion 
Airport, Tel Aviv, Israel, applied for a type certificate for its new 
Model G150 airplane. The Gulfstream Model G150 is a twin-engine, 
pressurized executive jet airplane with standard seating provisions for 
11 passenger/crew and allowance for baggage and optional equipment. 
This airplane will have a maximum takeoff weight of 26,000 pounds and 
will have two aft-mounted Honeywell TFE 731-40AR-200G engines.

Type Certification Basis

    Under the provisions of 14 CFR 21.17, GALP must show that 
Gulfstream Model 150 airplanes meet the applicable provisions of part 
25, effective February 1, 1965, as amended by Amendment 25-1 through 
Amendment 25-107.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for Gulfstream Model 150 airplanes 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 Gulfstream Model 150 airplanes 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; and the FAA must 
issue a finding of regulatory adequacy pursuant to section 611 of 
Public Law 92-574, the ``Noise Control Act of 1972.''
    Special conditions, as defined in Sec.  11.19, are issued in 
accordance with Sec.  11.38 and become part of the type certification 
basis in accordance with Sec.  21.17(a)(2).
    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, the special conditions would also apply to the 
other model.

Novel or Unusual Design Features

    Gulfstream Model G150 airplanes offer interior arrangements that 
include single-occupant side-facing seat installations. One arrangement 
includes an aft right-hand (RH) toilet installation, which will be 
approved for occupancy during taxi, takeoff, and landing. The belted 
toilet seat is a single-occupant side-facing seating system located in 
the aft, RH portion of the cabin. It consists of a toilet assembly, 
toilet cabinet, forward partition, contact pad, and restraint system 
(lap belt).
    The existing regulations do not provide adequate or appropriate 
safety standards for occupants of side-facing seats. In order to 
provide a level of safety that is equivalent to that afforded occupants 
of forward- and aft-facing seats, additional airworthiness standards, 
in the form of special conditions, are necessary. These special 
conditions supplement part 25 and, more specifically, supplement 
Sec. Sec.  25.562 and 25.785. The requirements contained in these 
special conditions consist of both test conditions and injury pass/fail 
criteria.

Discussion

    Section 25.785(b), ``Seats, berths, safety belts, and harnesses,'' 
requires that ``each seat * * * at each station designated as 
occupiable during takeoff and landing must be designed so that a person 
making proper use of these facilities will not suffer serious injury in 
an emergency landing as a result of the inertia forces specified in 
Sec. Sec.  25.561 and 25.562.'' Additionally, Sec.  25.562, ``Emergency 
landing dynamic conditions,'' requires dynamic testing of all seats 
occupied during takeoff and landing. The relative forces and injury 
mechanisms affecting the occupants of side-facing seats during an 
emergency landing are different from those of standard forward- or aft-
facing seats, or seats equipped with conventional restraint systems.
    Side-facing Seats: Amendment 25-64, which adopted Sec.  25.562, 
enhances occupant protection during emergency landing conditions. 
Although the rule was written with forward- and aft-facing seats in 
mind, the orientation of the seat does not change the relevant test 
conditions, and the rule applies to all seats regardless of 
orientation.
    The dynamic test conditions included in Sec.  25.562 are directly 
applicable to side-facing seats. However, for injury pass/fail 
criteria, the orientation of the seat may be significant. For forward-, 
aft-, and side-facing seats the injury criteria are currently limited 
to head, spine, and femur loads. The head and lumbar loads are critical 
but the femur load is not critical. For a side-facing seat, additional 
injury parameters may be identified and evaluation of those parameters 
would be necessary to provide an acceptable level of safety.
    When evaluating side-facing seats the following should be taken 
into consideration:
    1. The isolation of one occupant from another. Occupants should not 
rely on impact with other occupants to provide energy absorption; body-
to-body impacts are unacceptable.
    2. The restraint system and the retention of occupants in the seat. 
Addressing this concern may necessitate providing a means of restraint 
for the

[[Page 48844]]

lower limbs as well as the torso. Failure to limit the forward (in the 
airplane's coordinate system) travel of the lower limbs may cause the 
occupant to come out of the restraint system or produce severe injuries 
due to the resulting position of the restraint system and/or twisting 
(torsional load) of the lower lumber spinal column.
    3. The load limit in the torso in the lateral direction. Human 
tolerance for side-facing seats differs from that for forward- or aft-
facing seats.
    The automotive industry has developed test procedures and occupant 
injury criteria appropriate for side impact conditions. The criteria 
includes limiting lateral pelvic accelerations and using the ``Thoracic 
Trauma Index,'' which is defined in 49 CFR 571.214. Use of the Side 
Impact Dummy (SID) identified in 49 CFR part 572, subpart F, rather 
than the Hybrid II dummy identified in 49 CFR part 572, subpart B, is 
required to evaluate these parameters. The Hybrid II dummy is used in 
the current Sec.  25.562 test. Testing with a SID is the best means 
available to assess the injury potential of a sideward impact 
condition. Such an evaluation is considered necessary to provide an 
acceptable level of safety for side-facing seats.
    The side-facing seat special conditions have been determined to 
result in a level of safety equivalent to that provided by the injury 
pass/fail criteria in Sec.  25.562 for forward- or aft-facing seats.

Applicability

    As discussed above, these special conditions are applicable to 
Gulfstream Model G150 airplanes. Should GALP apply at a later date for 
a change to the type certificate to include another model 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 Gulfstream Model G150 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.
    The substance of these special conditions has been subjected to the 
notice and comment period in several prior instances and has been 
derived without substantive change from those previously issued. It is 
unlikely that prior public comment would result in a significant change 
from the substance contained herein. For this reason, and because a 
delay would significantly affect the certification of the airplane, 
which is imminent, the FAA has determined that prior public notice and 
comment are unnecessary and impracticable, and good cause exists for 
adopting these special conditions upon issuance. 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.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.


0
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 Gulfstream Model G150 airplanes.
    In addition to the airworthiness standards of Sec. Sec.  25.562 and 
25.785, the minimum acceptable standards for dynamic certification of 
single-occupant side-facing seats on Gulfstream Model G150 airplanes 
are as follows:

Additional Injury Criteria

    (a) Existing Criteria: All injury protection criteria of Sec. Sec.  
25.562(c)(1) through (c)(6) apply to the occupant of a side-facing 
seat. Head Injury Criterion (HIC) assessments are required only for 
head contact with the seat and/or adjacent structures.
    (b) Body-to-Wall/Furnishing Contact: The seat must be installed 
immediately aft of a structure, such as an interior wall or furnishing, 
that will support the pelvis, upper arm, chest, and head of an occupant 
seated next to the structure. A conservative representation of the 
structure and its stiffness must be included in the tests. It is 
recommended, but not required, that the contact surface of this 
structure be covered with at least two inches of energy-absorbing 
protective padding (foam or equivalent), such as Ensolite.
    (c) Thoracic Trauma: The Thoracic Trauma Index (TTI) injury 
criterion must be substantiated by dynamic test or by rational 
analysis, based on a previous test or tests of a similar seat 
installation. Testing must be conducted with a Side Impact Dummy (SID), 
as defined in 49 CFR part 572, subpart F, or its equivalent. The TTI 
must be less than 85, as defined in 49 CFR part 572, subpart F. The TTI 
data must be processed as defined in Federal Motor Vehicle Safety 
Standard (FMVSS) part 571.214, section S6.13.5.
    (d) Pelvis: Pelvic lateral acceleration must be shown by dynamic 
test or by rational analysis based on previous test(s) of a similar 
seat installation to not exceed 130g. Pelvic acceleration data must be 
processed as defined in FMVSS part 571.214, section S6.13.5.
    (e) Shoulder Strap Loads: Where upper torso straps (shoulder 
straps) are used for occupants, tension loads in individual straps must 
not exceed 1,750 pounds. If dual straps are used for restraining the 
upper torso, the total strap tension loads must not exceed 2,000 
pounds.

Additional Test Requirements

    The above performance measures must not be exceeded during the 
following dynamic tests:
    (a) Conduct a longitudinal test per Sec.  25.562(b)(2) with a SID, 
undeformed floor, no yaw, and with all lateral structural supports 
(armrests/walls).
    Pass/fail injury assessments: The TTI and pelvic acceleration.
    (b) Conduct a longitudinal test per Sec.  25.562(b)(2) with the 
Hybrid II Anthropomorphic Test Dummy (ATD), deformed floor, 10 degrees 
yaw, and with all lateral structural supports (armrests/walls).
    Pass/fail injury assessments: The HIC, upper torso restraint load, 
restraint system retention and pelvic acceleration.
    (c) Conduct a vertical test per Sec.  25.562(b)(1) with a Hybrid II 
ATD with existing pass/fail criteria.

    Issued in Renton, Washington, on August 9, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-16517 Filed 8-19-05; 8:45 am]
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