Document ID: FAA-2014-0667-0001
Agency: faa
Document Type: Rule
Title: Special Conditions: Boeing Model 777-300ER, Single-Occupant, Oblique (Side-Facing) Seats with Inflatable Lapbelts
Posted Date: 2014-09-25T04:00Z

[Federal Register Volume 79, Number 186 (Thursday, September 25, 2014)]
[Rules and Regulations]
[Pages 57429-57431]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-22781]

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  Federal Register / Vol. 79, No. 186 / Thursday, September 25, 2014 / 
Rules and Regulations  

[[Page 57429]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2014-0667; Special Conditions No. 25-569-SC]

Special Conditions: Boeing Model 777-300ER, Single-Occupant, 
Oblique (Side-Facing) Seats With Inflatable Lapbelts

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special condition; request for comments.

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SUMMARY: These special conditions are issued for Boeing Model 777-300ER 
airplanes with single-occupant, oblique (side-facing) seats equipped 
with inflatable lapbelts. This installation is novel or unusual, and 
the applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for occupants of seats installed at an 
oblique angle of 30 degrees to the centerline of the airplane or for 
inflatable restraint systems. 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 September 25, 
2014. We must receive your comments by November 10, 2014.

ADDRESSES: Send comments identified by docket number FAA-2014-0667 
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 the 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: John Shelden, Airframe and Cabin 
Safety, ANM-115, Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone 
425-227-2785; facsimile 425-227-1232; email john.shelden@faa.gov.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and 
opportunity for prior public comment on, these special conditions are 
impracticable because such procedures would significantly delay 
issuance of the design approval and thus the delivery of the affected 
airplane, and such impracticability was not of the applicant's 
creation. The FAA therefore finds that good cause exists for making 
these special conditions effective upon publication in the Federal 
Register.

Comments Invited

    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 July 18, 2014, Boeing Commercial Airplanes, P.O. Box 3707, 
Seattle, Washington 98124, applied for a type certificate design change 
to type certificate no. T00001SE to install single-occupant seats 
installed at an oblique angle to the centerline of the airplane, and 
which are equipped with inflatable lapbelts, in Boeing Model 777-300ER 
airplanes. The Model 777 series airplane is a swept-wing, conventional-
tail, twin-engine, turbofan- powered, transport-category airplane.
    Amendment 25-15 to part 25, dated October 24, 1967, introduced the 
subject of side-facing seats and a requirement that each occupant in a 
side-facing seat must be protected from head injury by a safety belt 
and a cushioned rest that will support the arms, shoulders, head, and 
spine.
    Subsequently, Amendment 25-20, dated April 23, 1969, clarified the 
definition of sideward-facing seats to require that each occupant of a 
seat that is positioned at more than an 18-degree angle to the vertical 
plane containing the airplane centerline must be protected from head 
injury by a safety belt and an energy-absorbing rest that supports the 
arms, shoulders, head, and spine; or by a safety belt and shoulder 
harness that prevents the head from contacting injurious objects. The 
FAA concluded that a maximum 18-degree angle would provide an adequate 
level of safety based on tests that were performed at that time, and 
thus adopted that standard.
    Part 25 was amended June 16, 1988, by Amendment 25-64, to revise 
the emergency-landing conditions that must be considered in the design 
of the airplane. Amendment 25-64 revised the static-load conditions in 
Sec.  25.561, and added a new Sec.  25.562 that required

[[Page 57430]]

dynamic testing for all seats approved for occupancy during takeoff and 
landing. The intent of Amendment 25-64 is to provide an improved level 
of safety for occupants on transport-category airplanes. Because most 
seating is forward-facing on transport-category airplanes, the pass/
fail criteria developed in Amendment 25-64 focused primarily on these 
seats. As a result, the FAA issued Policy Memorandums ANM-03-115-30 and 
PS-ANM-100-2000-00123 to provide additional guidance to demonstrate the 
level of safety required by the regulations for side-facing seats.
    To address more recent research findings, the FAA developed a 
methodology to address all fully side-facing seats (i.e, seats oriented 
in the airplane with the occupant facing 90 degrees to the direction of 
airplane travel) and has documented those requirements in a set of 
proposed new special conditions. In this regard, the FAA has issued 
Policy Statement PS-ANM-25-03-R1, which conveys revised injury criteria 
associated with neck and leg injuries.
    The Model 777-300ER China Airlines business-class seat installation 
is novel or unusual in that the current airworthiness standards, and 
the current Model 777 side-facing-seat special conditions, do not 
contain adequate or appropriate safety standards, regarding occupants' 
neck and spine, for oblique (side-facing) seat installation that 
restricts the occupant's knees/legs from aligning with both the upper 
torso and the impact vector during a forward event. As such, the Boeing 
Company proposes a revised seating configuration that requires new 
special conditions.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Boeing must show that the 
777-300ER meets the applicable provisions of 14 CFR part 25, as amended 
by Amendments 25-128, except for earlier amendments as agreed upon by 
the FAA. These regulations will be incorporated into type certificate 
no. T00001SE after type certification approval of the 777-300ER. The 
regulations incorporated by reference in T00001SE are as follows:
    The type-certification basis for the Model 777-300ER airplane is 14 
CFR part 25, effective February 1, 1965, as amended by Amendments 25-1 
through 25-98, including special conditions 25-295-SC and 25-187A-SC. 
In addition, the certification basis includes certain special 
conditions, exemptions, or later amended sections of the applicable 
part that are not relevant to these proposed special conditions.
    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 Boeing Model 777-300ER 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, the special conditions would also apply to the 
other model.
    In addition to the applicable airworthiness regulations and special 
conditions, the Boeing Model 777-300ER 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 777-300ER airplane will incorporate the following 
novel or unusual design features:
    The seating configuration proposed by Boeing in Certification Plan 
No. 13668, ``Installation of B/E Aerospace Business Class Seats on 
China Airlines (CHI) WE501,'' which consists of Super Diamond model, 
oblique (side-facing), business-class passenger seats, manufactured by 
B/E Aerospace, in a Boeing Model 777-300ER airplane. These seats will 
also incorporate inflatable restraints.
    The applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for occupants of seats installed in the 
proposed configuration. To provide a level of safety equivalent to that 
afforded to occupants of forward- and aft-facing seats, additional 
airworthiness standards, in the form of special conditions, are 
necessary.
    Although special conditions 25-295-SC and 25-187A-SC already apply 
to the 777-300ER, these do not directly address the complex occupant-
loading conditions introduced by this oblique (side-facing) seat 
configuration. In addition, this seat-angle configuration is not 
specifically addressed in Policy Statement PS-ANM-25-03-R1, which is 
intended to address fully side-facing seats, i.e., 90-degree 
installation angle.

Discussion

    Boeing's proposed seating configuration could introduce complex 
loading of the occupant. In conjunction with the 30-degree oblique 
(side-facing) orientation of the seats, surrounding structure restricts 
the occupant's knees and legs, in a forward event, from aligning with 
both the upper torso and the impact vector. In addition, the inflatable 
lapbelt design, intended to provide occupant restraint and injury 
prevention, introduces a significant rebound flail of the head and 
neck.
    The level of safety intended by current rules is that aircraft 
seating configurations protect the occupant from serious injury. 
Development testing of the proposed seating configuration has shown 
that the inflatable restraint contributes to loading of the head and 
neck in the fore and aft directions, and has also produced significant 
head twisting. National Highway Traffic Safety Administration (NHTSA) 
regulations specify neck injury criteria for the 50th percentile male 
as part of the FMVSS No. 208 alternative test, S13.2. Therefore, we 
find that it is appropriate to adopt the same neck-injury criteria used 
in the FMVSS 571.208, and measure it using the FAA Hybrid III 
anthropomorphic test dummy (ATD). The neck injury criteria, called 
``Nij'', imposes critical limits for all four possible modes 
of neck loading; tension or compression combined with either flexion 
(forward) or extension (rearward) bending moment. The Nij is 
defined as the sum of the normalized loads and moments of the neck load 
cells installed in the ATD. We will also limit the head rotation based 
on existing relevant research literature. Impact of the neck with any 
surface could cause serious neck injury from concentrated loading; 
therefore these special conditions do not allow such contact.
    Preliminary results from FAA-sponsored oblique-seat research 
indicate that unrestricted flailing of the upper torso during forward 
impacts can produce significant injuries. Although specific injury 
criteria to predict these injuries is not yet available, limiting the 
amount of forward flailing has been observed to reduce the magnitude 
and duration of spinal loading. Therefore, these special conditions 
require that seat designs limit the forward flail of the upper body to 
reduce the risk of these injuries.
    These special conditions contain the additional safety standards 
that the Administrator considers necessary to

[[Page 57431]]

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 777-300ER airplane. Should Boeing 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 one model of airplane. It is not a rule of general applicability.
    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 
Model 777-300ER airplane is imminent, the FAA finds that good cause 
exists to make these special conditions effective upon publication in 
the Federal Register.

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 777-300ER airplanes.

Inflatable Lapbelt Special Conditions

    The inflatable lapbelts must meet the criteria of Special 
Conditions 25-187A-SC.

Single-Occupant, Oblique (side-facing) Seats Special Conditions

    1. Longitudinal (16g) occupant injury test(s), must be performed 
with the FAA Hybrid III ATD, undeformed floor, most critical yaw 
case(s) for injury, and with all lateral structural supports (armrests/
walls). The criteria for the pass/fail injury assessments are listed in 
special conditions 2 through 5 in this section.
    2. Existing Criteria: All injury protection criteria of Sec.  
25.562(c)(1) through (c)(6) apply to the occupant of an oblique (side-
facing) seat. Head injury criterion (HIC) assessments are only required 
for head contact with the seat and/or adjacent structures. If there is 
no apparent contact with seat/structure but there is contact with an 
inflatable restraint, the HIC15 score for that contact must be less 
than 700.
    3. Body-to-Wall/Furnishing Contact Criteria: If an oblique (side-
facing) seat is installed aft of structure (e.g., an interior wall or 
furnishing) that does not provide a homogenous contact surface for the 
expected range of occupants and yaw angles, then additional analysis 
and/or test(s) may be required to demonstrate that the injury criteria 
are met for the area which an occupant could contact. For example, if 
difference yaw angles could result in different inflatable restraint 
performance then additional analysis or separate test(s) may be 
necessary to evaluate.
    4. Neck-Injury Criteria:
    a. In demonstrating that the design meets the criteria of FMVSS 
571.208, the applicant must show the Nij to be below 1.0, 
where Nij =Fz/Fzc + My/
Myc, and Nij intercepts limited to:

    i. Fzc = 1530 lb for tension
    ii. Fzc = 1385 lb for compression
    iii. Myc = 229 lb-ft in flexion
    iv. Myc = 100 lb-ft in extension

    b. In addition, peak Fz must be below 937 lb in tension 
and 899 lb in compression.
    c. Rotation of the head about its vertical axis relative to the 
torso is limited to 105 degrees in either direction from forward-
facing.
    d. The neck must not impact any surface.
    5. Spine and Torso Injury Criteria:
    a. The shoulders must remain aligned with the hips throughout the 
impact sequence, or support for the upper torso must be provided to 
prevent forward or lateral flailing beyond 45 degrees from the vertical 
during significant spinal loading.
    b. Occupant must not interact with the armrest or other seat 
components in any manner significantly different than would be expected 
for a forward-facing seat installation.
    6. One longitudinal (16g) structural test must be performed with 
the Hybrid II ATD or FAA Hybrid III, deformed floor, with 10 degrees 
yaw, and with all lateral structural supports (armrests/walls). Use 
existing structural pass/fail criteria from Sec.  25.562.
    7. One vertical (14g) test must be conducted with Hybrid II ATDs or 
FAA Hybrid III. Use existing pass/fail structural and injury criteria 
from Sec.  25.562.

    Note: The applicant must demonstrate that the installation of 
seats via plinths or pallets meets all applicable requirements. 
Compliance with the guidance contained in FAA Policy Memorandum PS-
ANM-100-2000-00123, dated February 2, 2000, titled ``Guidance for 
Demonstrating Compliance with Seat Dynamic Testing for Plinths and 
Pallets,'' is acceptable to the FAA.

    Issued in Renton, Washington September 19, 2014.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-22781 Filed 9-24-14; 8:45 am]
BILLING CODE 4910-13-P