Special Conditions: The Boeing Company Model 787 Series Airplane; Seats With Pretensioner Restraint Systems, 68801-68803 [2020-23153]
Download as PDF
68801
Proposed Rules
Federal Register
Vol. 85, No. 211
Friday, October 30, 2020
This section of the FEDERAL REGISTER
contains notices to the public of the proposed
issuance of rules and regulations. The
purpose of these notices is to give interested
persons an opportunity to participate in the
rule making prior to the adoption of the final
rules.
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA–2020–0720; Notice No. 25–
20–08–SC]
Special Conditions: The Boeing
Company Model 787 Series Airplane;
Seats With Pretensioner Restraint
Systems
Federal Aviation
Administration (FAA), DOT.
ACTION: Notice of proposed special
conditions.
AGENCY:
This action proposes special
conditions for The Boeing Company
(Boeing) Model 787 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 pretensioner restraint systems
installed on passenger seats. The
applicable airworthiness regulations do
not contain adequate or appropriate
safety standards for this design feature.
These proposed 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: Send comments on or before
December 4, 2020.
ADDRESSES: Send comments identified
by Docket No. FAA–2020–0720 using
any of the following methods:
• Federal eRegulations Portal: Go to
https://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
jbell on DSKJLSW7X2PROD with PROPOSALS
SUMMARY:
VerDate Sep<11>2014
16:56 Oct 29, 2020
Jkt 253001
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 https://www.regulations.gov/,
including any personal information the
commenter provides. Using the search
function of the docket website, 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).
Docket: Background documents or
comments received may be read at
https://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:
Shannon Lennon, Airframe and Cabin
Safety Section, AIR–675, 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
shannon.lennon@faa.gov.
SUPPLEMENTARY INFORMATION:
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. The FAA may change these
special conditions based on the
comments received.
Background
On November 8, 2018, Boeing applied
for a change to Type Certificate No.
PO 00000
Frm 00001
Fmt 4702
Sfmt 4702
T00021SE for pretensioner restraint
systems installed on passenger seats in
the Model 787 series airplane. This
airplane is a twin-engine, transportcategory airplane with passenger seating
capacity of 420 and a maximum takeoff
weight of 557,000 pounds.
Type Certification Basis
Under the provisions of title 14, Code
of Federal Regulations (14 CFR) 21.101,
Boeing must show that the Model 787
series airplane, as changed, continues to
meet the applicable provisions of the
regulations listed in Type Certificate No.
T00021SE 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 Boeing Model 787 series airplane
because of a novel or unusual design
feature, special conditions are
prescribed under the provisions of
§ 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 § 21.101.
In addition to the applicable
airworthiness regulations and special
conditions, the Boeing Model 787 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 § 11.38, and they become part of
the type certification basis under
§ 21.101.
Novel or Unusual Design Features
The Boeing Model 787 series airplane
will incorporate the following novel or
unusual design features:
Forward-facing seats incorporating a
shoulder harness with pretensioner
device, otherwise known as a
E:\FR\FM\30OCP1.SGM
30OCP1
68802
Federal Register / Vol. 85, No. 211 / Friday, October 30, 2020 / Proposed Rules
jbell on DSKJLSW7X2PROD with PROPOSALS
pretensioner restraint system, which is
intended to protect the occupants from
head injuries.
Discussion
Boeing will install, in the Model 787
series airplane, forward-facing seats that
incorporate a shoulder harness with a
pretensioner system at each seat place
for head-injury protection.
Shoulder harnesses have been widely
used on flight-attendant seats, flightdeck seats, in business jets, and in
general-aviation airplanes to reduce
occupant head injury in the event of an
emergency landing. Special conditions,
pertinent regulations, and published
guidance exist that relate to other
restraint systems. However, the use of
pretensioners in the restraint system on
transport-airplane seats is a novel
design.
The pretensioner restraint system
utilizes a retractor which eliminates
slack in the shoulder harness and pulls
the occupant back into the seat prior to
impact. This has the effect of reducing
forward translation of the occupant,
reducing head arc, and reducing the
loads in the shoulder harness.
Pretensioner technology involves a
step-change in loading experienced by
the occupant for impacts below and
above that at which the device deploys,
because activation of the shoulder
harness, at the point at which the
pretensioner engages, interrupts uppertorso excursion. This could result in the
head injury criteria (HIC) being higher at
an intermediate impact condition than
that resulting from the maximum impact
condition corresponding to the test
conditions specified in § 25.562. See
condition 1 in these special conditions.
The ideal triangular maximumseverity pulse is defined in Advisory
Circular (AC) 25.562–1B, ‘‘Dynamic
Evaluation of Seat Restraint Systems
and Occupant Protection on Transport
Airplanes.’’ For the evaluation and
testing of less-severe pulses for purposes
of assessing the effectiveness of the
pretensioner setting, a similar triangular
pulse should be used with acceleration,
rise time, and velocity change scaled
accordingly. The magnitude of the
required pulse should not deviate below
the ideal pulse by more than 0.5g until
1.33 t1 is reached, where t1 represents
the time interval between 0 and t1 on
the referenced pulse shape as shown in
AC 25.562–1B. This is an acceptable
method of compliance to the test
requirements of the special conditions.
Additionally, the pretensioner might
not provide protection, after actuation,
during secondary impacts. Therefore,
the case where a small impact is
followed by a large impact should be
VerDate Sep<11>2014
16:56 Oct 29, 2020
Jkt 253001
addressed. If the minimum deceleration
severity at which the pretensioner is set
to deploy is unnecessarily low, the
protection offered by the pretensioner
may be lost by the time a second, larger
impact occurs.
Conditions 1 through 4 ensure that
the pretensioner system activates when
intended, to provide the necessary
protection of occupants. This includes
protection of a range of occupants under
various accident conditions. Conditions
5 through 10 address maintenance and
reliability of the pretensioner system,
including any outside influences on the
mechanism, to ensure it functions as
intended.
The proposed 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 787 series 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, these special
conditions would apply to that 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 Proposed Special Conditions
§ 25.562 Emergency landing dynamic
conditions.
Accordingly, the Federal Aviation
Administration (FAA) proposes the
following special conditions as part of
the type certification basis for the
Boeing Model 787 series airplane.
In addition to the requirements of
§ 25.562, forward-facing passenger seats
with pretensioner restraint systems
must meet the following:
1. Head Injury Criteria (HIC)
The HIC value must not exceed 1000
at any condition at which the
pretensioner does or does not deploy,
up to the maximum severity pulse that
PO 00000
Frm 00002
Fmt 4702
Sfmt 4702
corresponds to the test conditions
specified in § 25.562. Tests must be
performed to demonstrate this, taking
into account any necessary tolerances
for deployment.
When an airbag device is present in
addition to the pretensioner restraint
system, and the anthropormorphic test
device (ATD) has no apparent contact
with the seat/structure but has contact
with an airbag, a HIC unlimited scored
in excess of 1000 is acceptable,
provided the HIC15 score (calculated in
accordance with 49 CFR 571.208) for
that contact is less than 700.
ATD head contact with the seat or
other structure, through the airbag, or
contact subsequent to contact with the
airbag, requires a HIC value that does
not exceed 1000.
2. Protection During Secondary Impacts
The pretensioner activation setting
must be demonstrated to maximize the
probability of the protection being
available when needed, considering
secondary impacts.
3. Protection of Occupants Other Than
50th Percentile
Protection of occupants for a range of
stature from a 2-year-old child to a 95th
percentile male must be shown. For
shoulder harnesses that include
pretensioners, protection of occupants
other than a 50th percentile male may
be shown by test or analysis. In
addition, the pretensioner must not
introduce a hazard to passengers due to
the following seating configurations:
a. The seat occupant is holding an
infant.
b. The seat occupant is a child in a
child-restraint device.
c. The seat occupant is a pregnant
woman.
4. Occupants Adopting the Brace
Position
Occupants in the traditional brace
position when the pretensioner activates
must not experience adverse effects
from the pretensioner activation.
5. Inadvertent Pretensioner Actuation
a. The probability of inadvertent
pretensioner actuation must be shown
to be extremely remote (i.e., average
probability per flight hour of less than
10¥7).
b. The system must be shown to be
not susceptible to inadvertent
pretensioner actuation as a result of
wear and tear, nor inertia loads resulting
from in-flight or ground maneuvers
likely to be experienced in service.
c. The seated occupant must not be
seriously injured as a result of
inadvertent pretensioner actuation.
E:\FR\FM\30OCP1.SGM
30OCP1
Federal Register / Vol. 85, No. 211 / Friday, October 30, 2020 / Proposed Rules
d. Inadvertent pretensioner actuation
must not cause a hazard to the airplane,
nor cause serious injury to anyone who
may be positioned close to the retractor
or belt (e.g., seated in an adjacent seat
or standing adjacent to the seat).
6. Availability of the Pretensioner
Function Prior To Flight
The design must provide means for a
crewmember to verify the availability of
the pretensioner function prior to each
flight, or the probability of failure of the
pretensioner function must be
demonstrated to be extremely remote
(i.e., average probability per flight hour
of less than 10¥7) between inspection
intervals.
7. Incorrect Seat Belt Orientation
The system design must ensure that
any incorrect orientation (twisting) of
the seat belt does not compromise the
pretensioner protection function.
8. Contamination Protection
The pretensioner mechanisms and
controls must be protected from external
contamination associated with that
which could occur on or around
passenger seating.
9. Prevention of Hazards
The pretensioner system must not
induce a hazard to passengers in case of
fire, nor create a fire hazard, if activated.
10. Functionality After Loss of Power
The system must function properly
after loss of normal airplane electrical
power, and after a transverse separation
in the fuselage at the most critical
location. A separation at the location of
the system does not have to be
considered.
Issued in Des Moines, Washington, on
October 14, 2020.
James E. Wilborn,
Acting Manager, Transport Standards
Branch, Policy and Innovation Division,
Aircraft Certification Service.
[FR Doc. 2020–23153 Filed 10–29–20; 8:45 am]
BILLING CODE 4910–13–P
CONSUMER PRODUCT SAFETY
COMMISSION
[Docket No. CPSC–2020–0024]
jbell on DSKJLSW7X2PROD with PROPOSALS
16 CFR Part 1632
Standard for the Flammability of
Mattresses and Mattress Pads;
Proposed Amendment
Consumer Product Safety
Commission.
ACTION: Proposed rule.
AGENCY:
VerDate Sep<11>2014
16:56 Oct 29, 2020
Jkt 253001
The Consumer Product Safety
Commission (Commission, or CPSC) is
proposing to amend its Standard for the
Flammability of Mattresses and Mattress
Pads. The ignition source cigarette
specified in the standard for use in the
mattress standard’s performance tests,
Standard Reference Material cigarette
SRM 1196, is no longer available for
purchase. The Commission is proposing
to amend the mattress standard to
require a revised Standard Reference
Material cigarette, SRM 1196a, which
was developed by the National Institute
of Standards and Technology, as the
ignition source for testing to the
mattress standard.
DATES: Comments on the proposal
should be submitted no later than
January 13, 2021.
ADDRESSES: Comments, identified by
Docket No. CPSC–2020–0024, may be
submitted electronically or in writing:
Electronic Submissions: Submit
electronic comments to the Federal
eRulemaking Portal at: https://
www.regulations.gov. Follow the
instructions for submitting comments.
The CPSC does not accept comments
submitted by electronic mail (email),
except through https://
www.regulations.gov. The CPSC
encourages you to submit electronic
comments by using the Federal
eRulemaking Portal, as described above.
Mail/hand delivery/courier Written
Submissions: Submit comments by
mail/hand delivery/courier to: Division
of the Secretariat, Consumer Product
Safety Commission, Room 820, 4330
East-West Highway, Bethesda, MD
20814; telephone: (301) 504–7479;
email: amills@cpsc.gov.
Instructions: All submissions must
include the agency name and docket
number for this proposed rule. CPSC
may post all comments received without
change, including any personal
identifiers, contact information, or other
personal information provided, to:
https://www.regulations.gov. Do not
submit electronically: confidential
business information, trade secret
information, or other sensitive or
protected information that you do not
want to be available to the public. If you
wish to submit such information, please
submit it according to the instructions
for written submissions.
Docket: For access to the docket to
read background documents or
comments received, go to: https://
www.regulations.gov, and insert the
docket number, CPSC–2020–0024, into
the ‘‘Search’’ box, and follow the
prompts.
FOR FURTHER INFORMATION CONTACT: Lisa
Scott, Directorate for Laboratory
SUMMARY:
PO 00000
Frm 00003
Fmt 4702
Sfmt 4702
68803
Sciences, Office of Hazard Identification
and Reduction, U.S. Consumer Product
Safety Commission, 5 Research Place,
Rockville, MD 20850; telephone: 301–
987–2064; email: lscott@cpsc.gov.
SUPPLEMENTARY INFORMATION:
A. Background
1. The Standard
The Standard for the Flammability of
Mattresses and Mattress Pads
(Standard), 16 CFR part 1632, issued
pursuant to the Flammable Fabrics Act
(FFA), 15 U.S.C. 1191 et seq., sets forth
a test to determine the ignition
resistance of a mattress or mattress pad
when exposed to a lighted cigarette.
Lighted cigarettes are placed at specified
locations on the surface of a mattress or
mattress pad. The Standard establishes
pass/fail criteria for the tests. The
Standard currently specifies the ignition
source for these tests as Standard
Reference Material cigarette SRM 1196,
available for purchase from the National
Institute of Standards and Technology
(NIST). See 16 CFR 1632.4(a)(2).
2. Development of the Original Standard
Reference Material Cigarette
The original specification for the
Standard’s ignition source included
physical characteristics of a
conventional, commercially available,
non-filtered, king-sized cigarette.
Although no specific brand was
identified in the standard, a Pall Mall
Red cigarette, manufactured by R.J.
Reynolds Tobacco Company (RJR), was
commonly known to meet the
specifications. In early 2008, RJR
notified CPSC that the company
intended to convert its production of
Pall Mall Red cigarettes to be Fire
Standard Compliant (FSC).
In 2008, CPSC sought to find an
alternate ignition source and contracted
with NIST to develop an ignition source
with an ignition strength equivalent to
the conventional Pall Mall Red cigarette.
The ignition strength value is on a scale
from 0 to 100 and is analogous to the
percentage of full-length burns on a
laboratory substrate. Lower values
indicate a cigarette is more likely to selfextinguish when not actively being
smoked, while higher values indicate a
cigarette is more likely to remain lit
while unattended. The Pall Mall Red
ignition strength varied by vintage from
a measured low of 35 to a high of 95,
most often falling at the higher end of
the range. FSC cigarettes are required to
have an ignition strength lower than 25
and in practice are often much weaker
to ensure uniform compliance.
In 2010, NIST developed SRM 1196,
Standard Cigarette for Ignition
E:\FR\FM\30OCP1.SGM
30OCP1
Agencies
[Federal Register Volume 85, Number 211 (Friday, October 30, 2020)]
[Proposed Rules]
[Pages 68801-68803]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-23153]
========================================================================
Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
========================================================================
Federal Register / Vol. 85, No. 211 / Friday, October 30, 2020 /
Proposed Rules
[[Page 68801]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2020-0720; Notice No. 25-20-08-SC]
Special Conditions: The Boeing Company Model 787 Series Airplane;
Seats With Pretensioner Restraint Systems
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
-----------------------------------------------------------------------
SUMMARY: This action proposes special conditions for The Boeing Company
(Boeing) Model 787 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 pretensioner restraint systems
installed on passenger seats. The applicable airworthiness regulations
do not contain adequate or appropriate safety standards for this design
feature. These proposed 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: Send comments on or before December 4, 2020.
ADDRESSES: Send comments identified by Docket No. FAA-2020-0720 using
any of the following methods:
Federal eRegulations Portal: Go to https://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 https://www.regulations.gov/, including any personal
information the commenter provides. Using the search function of the
docket website, 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).
Docket: Background documents or comments received may be read at
https://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: Shannon Lennon, Airframe and Cabin
Safety Section, AIR-675, 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 [email protected].
SUPPLEMENTARY INFORMATION:
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. The FAA may change these special conditions based on the
comments received.
Background
On November 8, 2018, Boeing applied for a change to Type
Certificate No. T00021SE for pretensioner restraint systems installed
on passenger seats in the Model 787 series airplane. This airplane is a
twin-engine, transport-category airplane with passenger seating
capacity of 420 and a maximum takeoff weight of 557,000 pounds.
Type Certification Basis
Under the provisions of title 14, Code of Federal Regulations (14
CFR) 21.101, Boeing must show that the Model 787 series airplane, as
changed, continues to meet the applicable provisions of the regulations
listed in Type Certificate No. T00021SE 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 Boeing Model 787 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 787 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 787 series airplane will incorporate the following
novel or unusual design features:
Forward-facing seats incorporating a shoulder harness with
pretensioner device, otherwise known as a
[[Page 68802]]
pretensioner restraint system, which is intended to protect the
occupants from head injuries.
Discussion
Boeing will install, in the Model 787 series airplane, forward-
facing seats that incorporate a shoulder harness with a pretensioner
system at each seat place for head-injury protection.
Shoulder harnesses have been widely used on flight-attendant seats,
flight-deck seats, in business jets, and in general-aviation airplanes
to reduce occupant head injury in the event of an emergency landing.
Special conditions, pertinent regulations, and published guidance exist
that relate to other restraint systems. However, the use of
pretensioners in the restraint system on transport-airplane seats is a
novel design.
The pretensioner restraint system utilizes a retractor which
eliminates slack in the shoulder harness and pulls the occupant back
into the seat prior to impact. This has the effect of reducing forward
translation of the occupant, reducing head arc, and reducing the loads
in the shoulder harness.
Pretensioner technology involves a step-change in loading
experienced by the occupant for impacts below and above that at which
the device deploys, because activation of the shoulder harness, at the
point at which the pretensioner engages, interrupts upper-torso
excursion. This could result in the head injury criteria (HIC) being
higher at an intermediate impact condition than that resulting from the
maximum impact condition corresponding to the test conditions specified
in Sec. 25.562. See condition 1 in these special conditions.
The ideal triangular maximum-severity pulse is defined in Advisory
Circular (AC) 25.562-1B, ``Dynamic Evaluation of Seat Restraint Systems
and Occupant Protection on Transport Airplanes.'' For the evaluation
and testing of less-severe pulses for purposes of assessing the
effectiveness of the pretensioner setting, a similar triangular pulse
should be used with acceleration, rise time, and velocity change scaled
accordingly. The magnitude of the required pulse should not deviate
below the ideal pulse by more than 0.5g until 1.33 t1 is reached, where
t1 represents the time interval between 0 and t1 on the referenced
pulse shape as shown in AC 25.562-1B. This is an acceptable method of
compliance to the test requirements of the special conditions.
Additionally, the pretensioner might not provide protection, after
actuation, during secondary impacts. Therefore, the case where a small
impact is followed by a large impact should be addressed. If the
minimum deceleration severity at which the pretensioner is set to
deploy is unnecessarily low, the protection offered by the pretensioner
may be lost by the time a second, larger impact occurs.
Conditions 1 through 4 ensure that the pretensioner system
activates when intended, to provide the necessary protection of
occupants. This includes protection of a range of occupants under
various accident conditions. Conditions 5 through 10 address
maintenance and reliability of the pretensioner system, including any
outside influences on the mechanism, to ensure it functions as
intended.
The proposed 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 787 series 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, these special
conditions would apply to that 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 Proposed Special Conditions
Sec. 25.562 Emergency landing dynamic conditions.
Accordingly, the Federal Aviation Administration (FAA) proposes the
following special conditions as part of the type certification basis
for the Boeing Model 787 series airplane.
In addition to the requirements of Sec. 25.562, forward-facing
passenger seats with pretensioner restraint systems must meet the
following:
1. Head Injury Criteria (HIC)
The HIC value must not exceed 1000 at any condition at which the
pretensioner does or does not deploy, up to the maximum severity pulse
that corresponds to the test conditions specified in Sec. 25.562.
Tests must be performed to demonstrate this, taking into account any
necessary tolerances for deployment.
When an airbag device is present in addition to the pretensioner
restraint system, and the anthropormorphic test device (ATD) has no
apparent contact with the seat/structure but has contact with an
airbag, a HIC unlimited scored in excess of 1000 is acceptable,
provided the HIC15 score (calculated in accordance with 49 CFR 571.208)
for that contact is less than 700.
ATD head contact with the seat or other structure, through the
airbag, or contact subsequent to contact with the airbag, requires a
HIC value that does not exceed 1000.
2. Protection During Secondary Impacts
The pretensioner activation setting must be demonstrated to
maximize the probability of the protection being available when needed,
considering secondary impacts.
3. Protection of Occupants Other Than 50th Percentile
Protection of occupants for a range of stature from a 2-year-old
child to a 95th percentile male must be shown. For shoulder harnesses
that include pretensioners, protection of occupants other than a 50th
percentile male may be shown by test or analysis. In addition, the
pretensioner must not introduce a hazard to passengers due to the
following seating configurations:
a. The seat occupant is holding an infant.
b. The seat occupant is a child in a child-restraint device.
c. The seat occupant is a pregnant woman.
4. Occupants Adopting the Brace Position
Occupants in the traditional brace position when the pretensioner
activates must not experience adverse effects from the pretensioner
activation.
5. Inadvertent Pretensioner Actuation
a. The probability of inadvertent pretensioner actuation must be
shown to be extremely remote (i.e., average probability per flight hour
of less than 10-7).
b. The system must be shown to be not susceptible to inadvertent
pretensioner actuation as a result of wear and tear, nor inertia loads
resulting from in-flight or ground maneuvers likely to be experienced
in service.
c. The seated occupant must not be seriously injured as a result of
inadvertent pretensioner actuation.
[[Page 68803]]
d. Inadvertent pretensioner actuation must not cause a hazard to
the airplane, nor cause serious injury to anyone who may be positioned
close to the retractor or belt (e.g., seated in an adjacent seat or
standing adjacent to the seat).
6. Availability of the Pretensioner Function Prior To Flight
The design must provide means for a crewmember to verify the
availability of the pretensioner function prior to each flight, or the
probability of failure of the pretensioner function must be
demonstrated to be extremely remote (i.e., average probability per
flight hour of less than 10-7) between inspection intervals.
7. Incorrect Seat Belt Orientation
The system design must ensure that any incorrect orientation
(twisting) of the seat belt does not compromise the pretensioner
protection function.
8. Contamination Protection
The pretensioner mechanisms and controls must be protected from
external contamination associated with that which could occur on or
around passenger seating.
9. Prevention of Hazards
The pretensioner system must not induce a hazard to passengers in
case of fire, nor create a fire hazard, if activated.
10. Functionality After Loss of Power
The system must function properly after loss of normal airplane
electrical power, and after a transverse separation in the fuselage at
the most critical location. A separation at the location of the system
does not have to be considered.
Issued in Des Moines, Washington, on October 14, 2020.
James E. Wilborn,
Acting Manager, Transport Standards Branch, Policy and Innovation
Division, Aircraft Certification Service.
[FR Doc. 2020-23153 Filed 10-29-20; 8:45 am]
BILLING CODE 4910-13-P