> U.S. Department\
> of Transportation
>
> **Federal Aviation\
> Administration**
>
> ![](media/image1.png){width="6.305555555555555in"
> height="0.16597222222222222in"}

+----+----------------------------------------+---+-----+----------------+
| Su | [INFORMATION]{.underline}: Policy      |   | Da  | May 6, 2005    |
| bj | Statement on Side‑Facing Seats on      |   | te: |                |
| ec | Transport Category Airplanes           |   |     |                |
| t: |                                        |   |     |                |
|    | #                                      |   |     |                |
+----+----------------------------------------+---+-----+----------------+
|    |                                        |   |     |                |
+----+----------------------------------------+---+-----+----------------+
| F  | Manager, Transport Airplane            |   | Re  | ANM-03-115-30  |
| ro | Directorate, Aircraft Certification    |   | ply |                |
| m: | Service, ANM-100                       |   | to  |                |
|    |                                        |   | At  |                |
|    |                                        |   | tn. |                |
|    |                                        |   | of: |                |
+----+----------------------------------------+---+-----+----------------+
|    |                                        |   |     |                |
+----+----------------------------------------+---+-----+----------------+
| T  | See Distribution                       |   | R   | §§ 25.562 and  |
| o: |                                        |   | egu | 25.785(a) at   |
|    |                                        |   | lat | Amendment      |
|    |                                        |   | ory | 25-64; Policy  |
|    |                                        |   | R   | Memorandum     |
|    |                                        |   | efe | dated November |
|    |                                        |   | ren | 19, 1997       |
|    |                                        |   | ce: |                |
+----+----------------------------------------+---+-----+----------------+
|    |                                        |   |     |                |
+----+----------------------------------------+---+-----+----------------+

## Summary

> The purpose of this memorandum is to update existing Federal Aviation
> Administration (FAA) certification policy on § 25.785(a) at Amendment
> 25-64 and § 25.562 for side-facing seats.

## Current Regulatory and Advisory Material

> Section 25.562(a), Amendment 25-64, requires that the seat and
> restraint system be designed to protect each occupant when (1) proper
> use is made of the seats, safety belts, and shoulder harnesses and (2)
> the occupant is exposed to loads resulting from the conditions
> prescribed in § 25.562(b).
>
> Section 25.785(a), Amendment 25-64, requires general occupant
> protection for occupants of seats that are occupied during takeoff and
> landing. This paragraph is currently codified as § 25.785(b).
>
> The FAA policy memorandum, "Side-Facing Seats on Transport Category
> Airplanes," dated November 19, 1997, describes dynamic test procedures
> and pass/fail criteria that are considered to provide an appropriate
> level of safety for occupants of both multiple place side-facing seats
> certified by exemptions and single place side-facing seats certified
> by special conditions on transport category airplanes.

### 

### **Relevant Past Practice**

> The performance measures of § 25.562(c) only address forward and aft
> facing seats. Side-facing seats are considered a novel design for
> transport category airplanes that include Amendment 25-64 in the
> certification basis, and were not considered when those airworthiness
> standards were promulgated. The existing regulations do not provide
> adequate or appropriate safety standards for occupants of side-facing
> seats because they do not consider the differences in the dynamic
> forces that would apply to a side-facing occupant. The FAA determined
> that a level of safety that is equivalent to that afforded to
> occupants of forward and aft-facing seating could be achieved by
> additional airworthiness standards, in the form of special conditions,
> for single occupant side-facing seats. However, for reasons discussed
> below, the best criteria currently available for evaluating multiple
> occupant side-facing seats (divans) do not ensure a level of safety
> that is equivalent to that afforded to occupants of forward and
> aft-facing seating. Therefore, the only certification method available
> for multiple occupant side-facing seats, for airplanes that include
> Amendment 25-64 in their certification basis, is through an exemption
> from the general injury requirements of § 25.785(a), Amendment 25-64,
> and § 25.562(a).
>
> The FAA policy memorandum, "Side-Facing Seats on Transport Category
> Airplanes," dated November 19, 1997, describes dynamic test procedures
> and pass/fail criteria which have been found acceptable as a method of
> certifying single and multiple occupant side-facing seats on transport
> category airplanes. Attached to that memorandum is guidance material
> in the form of draft issue papers that is used to develop project
> specific issue papers. These issue papers are used to establish the
> minimum acceptable testing and human injury criteria of special
> conditions for single occupant side-facing seats and exemptions for
> multiple occupant side-facing seats.

## Policy 

> We have reviewed the guidance in the November 19, 1997, memorandum,
> "Side-Facing Seats on Transport Category Airplanes" and its
> attachments, and provide revisions to the guidance below. Except as
> noted below, the 1997 memorandum still describes current FAA policy.
> Note that the FAA has ongoing research to further refine the
> compliance criteria for multiple occupancy seating with the goal of
> establishing an equivalent level of safety. In particular, we are
> researching the potential effects of multiple occupant side-facing
> seats on the potential for neck injuries. Without this information, we
> cannot find that the level of safety provided by these seats is
> equivalent to that required by the regulations. In contrast, we do not
> consider neck injury to be a significant issue for single occupant
> side-facing seats as long as such seats are located immediately behind
> structure, such as an interior wall or furnishing that would support
> the pelvis, upper arm, chest, and head of an occupant seated behind
> the structure. In the event refined criteria for multiple occupant
> side-facing seats are established, this policy will be updated
> accordingly.

#### Criteria for Multiple Occupant Side-Facing Seats

> The 1997 memorandum contains criteria that are considered to provide
> one acceptable method of justifying an adequate level of safety for
> exemptions for multiple occupant side-facing seats. One criterion
> regards prevention of "body-to-body" contact. It does not allow
> incidental contact of a leg, foot, arm or hand that would result in
> incapacitation of an occupant. Incidental contact of a leg, foot, arm
> or hand has not indicated a potential for injury during tests
> occurring since the 1997 memorandum was issued. We find that this
> criterion is no longer warranted and paragraph 1(b) of the (DRAFT)
> ISSUE PAPER, Attachment 1, is revised to delete it as a limitation.
> Note that contact between the head, pelvis, or shoulder area of
> adjacent Anthropomorphic Test Dummies (ATD) is still considered
> unacceptable.
>
> If a multiple occupant side-facing seat is installed aft of a
> structure such as an interior wall or furnishing, the1997 memorandum
> stated that two inches of padding should be provided on the surface of
> this structure where an occupant could contact it when subjected to
> the dynamic loads of § 25.562(b). Seat testing should also meet
> Thoracic Trauma Index (TTI), Head Injury Criterion (HIC) and lateral
> pelvic acceleration criteria for impacts against such structure. We
> have determined that if an adequate level of safety is provided when
> these injury parameters are met, padding is not necessary. Paragraph
> 1(e) of the (DRAFT) ISSUE PAPER, Attachment 1, is revised to state
> that padding is recommended, but not required. Dynamic tests, or
> rational analysis based on previous tests, should demonstrate that
> TTI, HIC and lateral pelvic acceleration criteria are met.
>
> The 1997 memorandum provides a guideline that all multiple occupant
> side-facing seats have end closures. End closures are used to prevent
> an occupant from translating off of the seat. We consider that use of
> the restraint system for this purpose is another acceptable means to
> achieve this objective. Therefore, all multiple occupant side-facing
> seats should have end closures or other means to prevent the ATD's
> pelvis from translating beyond the end of the seat. Paragraph 1(g) of
> the (DRAFT) ISSUE PAPER, Attachment 1, is updated to reflect this
> position.

Note that unless it is demonstrated that the seat and seat belts alone
are sufficient in restraining the occupant under the dynamic loads,
items such as end closures, walls or furnishings, whether attached to a
seat frame or not, that aid in restraining seated occupants must be
designed to meet the dynamic load conditions of § 25.562. These items
are an integral part of the seat restraint system and therefore must
comply with § 25.562(a) which states the following:

> "(a) The seat and [restraint system]{.underline} \[emphasis added\] in
> the airplane must be designed as prescribed in this section to protect
> each occupant during an emergency landing condition when...(2) The
> occupant is exposed to loads resulting from the conditions prescribed
> in this section."

Pre-test floor deformation for these items that are not attached to the
seat is not necessary, but can be included in the test if the resultant
geometric relationship of the seat and the additional item would
otherwise reduce the effectiveness of the item.

> The exemption limitations in the 1997 memorandum state that one
> longitudinal test should be conducted in accordance with
> § 25.562(b)(2) using a Side Impact Dummy (SID) in the center seat
> place. The exemptions granted for multiple occupant side-facing seats
> have not required a test with a SID in this location. The initial
> intent of a test with a SID in this location was to determine that an
> acceptable level of thorax protection exists from a collision with an
> armrest or other barrier installed just forward of the center seat
> place. However, tests have demonstrated that these armrests are not
> structural barriers that contribute significantly to thorax injury. We
> have determined that the existing injury criteria are sufficient to
> justify an exemption without a test using a SID in the center seat
> place to obtain TTI. Paragraph 2(b) of the (DRAFT) ISSUE PAPER,
> Attachment 1, is revised to reflect this change. A Hybrid II ATD or
> equivalent may be used in this location instead.
>
> Note that the pelvic lateral acceleration injury criterion still
> should be met at this seat location if pelvic contact with an
> armrest/structural barrier occurs. This criterion may be met by
> dynamic test or rational analysis based on previous test(s). A Hybrid
> II ATD or equivalent can be used to obtain pelvic lateral acceleration
> data. If in the future, rigid structure is placed between seat places
> (such as between the center and forward seat places) that would
> warrant assessment of TTI, a test with a SID in the appropriate seat
> place (such as the center seat place) would be needed.
>
> As discussed previously, we have found that an acceptable level of
> safety can be provided to justify an exemption without a test with a
> SID in the center seat place. We have also found that it is
> permissible to obtain occupant injury data with floor deformation and
> with the seat yawed 10 degrees because the differences in test results
> would not be substantial considering the level of safety determined to
> be adequate for this exemption. Based on this determination, the
> longitudinal tests specified in the 1997 memorandum have been modified
> to only include a minimum of one test. Paragraph 2(b) of the (DRAFT)
> ISSUE PAPER, Attachment 1, has been revised to reflect this policy. If
> a seat is installed aft of structure (e.g., an interior wall or
> furnishing) that does not have a homogeneous surface, more than one
> test may be necessary to demonstrate that the injury criteria are met
> for the area which an occupant could contact. For example, different
> yaw angles could result in different injury considerations and may
> necessitate separate tests to evaluate.

#### Criteria for Single Occupant Side-Facing Seats

> Paragraph 1(b) of the (DRAFT) ISSUE PAPER, Attachment 2, has been
> revised to clarify that padding of contact surfaces is recommended,
> but not required.

## Effect of Policy

> The general policy stated in this document does not constitute a new
> regulation or create what the courts refer to as a "binding norm." The
> office that implements policy should follow this policy when
> applicable to the specified project. Whenever an applicant's proposed
> method of compliance is outside this established policy, it must be
> coordinated with the policy issuing office, e.g., through the issue
> paper process or equivalent. Similarly, if the implementing office
> becomes aware of reasons that an applicant's proposal that meets this
> policy should not be approved, the office must coordinate its response
> with the policy issuing office.
>
> Applicants should expect that the certificating officials will
> consider this information when making findings of compliance relevant
> to new certificate actions, or actions relating to maintenance,
> alterations, and repairs. Also, as with all advisory material, this
> policy statement identifies one means, but not the only means, of
> compliance.
>
> Questions regarding this memorandum should be directed to Mike
> Thompson of the Airframe & Cabin Safety Branch, ANM-115. Mr.
> Thompson's telephone number is (425) 227-1157 and his e-mail address
> is michael.t.thompson@faa.gov.

**Implementation**

The compliance method discussed in this policy should be applied to type
certificate, amended type certificate, supplemental type certificate,
and amended supplemental type certification programs whose application
date is on or after the date the policy is finalized. For existing
certification programs whose application precedes the date this policy
is effective and the methods of compliance have already been coordinated
with and approved by the FAA or their designee, the applicant may
continue to follow the previously acceptable methods of compliance or
choose to follow the guidance contained in this policy.

> /s/
>
> Ali Bahrami
>
> Attachments

DISTRIBUTION:

Manager, Aircraft Engineering Division, AIR-100

Manager, Boston Aircraft Certification Office, ANE-150

Manager, New York Aircraft Certification Office, ANE-170

Manager, Ft. Worth Airplane Certification Office, ASW-150

Manager, Ft. Worth Special Certification Office, ASW-190

Manager, Atlanta Aircraft Certification Office, ACE-115A

Manager, Wichita Aircraft Certification Office, ACE-115W

Manager, Chicago Aircraft Certification Office, ACE-115C

Manager, Anchorage Airplane Certification Office, ACE-115N

Manager, Seattle Aircraft Certification Office, ANM-100S

Manager, Los Angeles Aircraft Certification Office, ANM-100L

Manager, Denver Airplane Certification Office, ANM-100D

Manager, Brussels Aircraft Certification Office, AEU-100

Manager, Small Airplane Directorate, ACE-100

Manager, Rotorcraft Directorate, ASW-100,

Manager, Engine and Propeller Directorate, ANE-100

**Attachment 1**

> ***(DRAFT)***
>
> ISSUE PAPER

+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+
| **PROJECT:**                            | **ITEM:** CI-1             |
+-----------------------------------------+----------------------------+
|                                         | **STAGE:** 2               |
+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+
| **REG. REF.:** §§ 11.25, 25.562, 25.785 | **DATE:** March 31, 2003   |
+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+
| **NATIONAL**                            | **ISSUE STATUS:** OPEN     |
|                                         |                            |
| **POLICY REF.:**                        |                            |
+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+
| **SUBJECT:** Dynamic Test Requirements  | **BRANCH ACTION:**         |
| for Side-Facing Divans (Sofas)          | ANM-115, AAM-630, ANM-102N |
+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+
|                                         | **COMPLIANCE**             |
|                                         |                            |
|                                         | **TARGET:** Pre-TC         |
+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+

*Petition for Exemption*

\*\*\*\*\*\*\*\*\*\*\* NOTE \*\*\*\*\*\*\*\*\*\*\*

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> field code references to be lost! Always use the \"Edit Variables\"
> selection from the \"Edit\" Menu. This text will not print!
>
> \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*

**STATEMENT OF ISSUE:** Side-facing seats are considered a novel design
for transport category airplanes that include Amendment 25-64 in the
certification basis, and were not considered when those airworthiness
standards were promulgated. The FAA has determined that the existing
regulations do not provide adequate or appropriate safety standards for
occupants of side-facing multiple occupant seats (divans). Additionally,
the best criteria currently available for evaluation of this type of
seating do not ensure a level of safety that is equivalent to that
afforded to occupants of forward and aft facing seating. Therefore, the
only certification method available for this type of seating, for
aircraft that include Amendment 25-64 in their certification basis, is
through an exemption from the general injury requirements of § 25.785(b)
and § 25.562(a).

This issue paper will be used to establish the minimum acceptable
testing and human injury criteria that will be applied to side-facing
divan certifications. This information will complement the exemption
process as defined in § 11.25 and in no way is intended to circumvent
the need to provide an acceptable public interest argument as required
per § 11.81(d).

**BACKGROUND:** 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 § 25.561, and added a new § 25.562 that required 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.

For multiple occupant side-facing seating, the best criteria currently
available cannot be said to provide an equivalent level of safety for
those occupants. Therefore, the only vehicle available for accepting
these installations will be through an exemption from the general injury
requirements of § 25.785(b) and § 25.562(a). The criteria contained in
this issue paper may be included in a petition for exemption from the
noted requirements if an applicant so chooses. Any petition for
exemption must also address why a grant of the petition would be in the
public interest, in accordance with § 11.81(d), and it should be
emphasized that this public interest requirement must be satisfied
regardless of the criteria that the divan is tested to.

**FAA POSITION:** The following proposed injury criteria and
installation/testing guidelines represent the minimum acceptable
standard for incorporation in a petition for exemption from the general
occupant injury criteria of §§ 25.785(b) and 25.562(a). Note that this
issue paper addresses an exemption from the general occupant injury
criteria of §§ 25.785(b) and 25.562(a) only. Compliance with the
structural requirements must be demonstrated for side-facing seats using
the same conditions for the test and pass/fail criteria as for fore- and
aft-facing seats.

**1. The Proposed Injury Criteria**

\(a\) [Existing Criteria]{.underline}: All injury protection criteria of
§ 25.562(c)(1) through (c)(6) apply to the occupants of side facing
seating. Head Injury Criterion (HIC) assessments are only required for
head contact with the seat and/or adjacent structures.

\(b\) [Body-to-Body Contact]{.underline}: Contact between the head,
pelvis, torso or shoulder area of one Anthropomorphic Test Dummy (ATD)
with the adjacent seated ATD's head, pelvis, torso or shoulder area is
not allowed during the tests conducted in accordance with § 25.562(b)(1)
and (b)(2). Contact during rebound is allowed.

\(c\) [Thoracic Trauma]{.underline}: If the torso of an ATD at the
forward most seat place impacts seat and/or adjacent structure during
testing, compliance with Thoracic Trauma Index (TTI) injury criterion
must be substantiated by dynamic test or by rational analysis based on
previous test(s) of a similar seat installation. TTI data must be
acquired with a Side Impact Dummy (SID), as defined by 49 CFR Part 572,
Subpart F, or an equivalent ATD or a more appropriate ATD and must be
processed as defined in Federal Motor Vehicle Safety Standard (FMVSS)
Part 571.214, section S6.13.5. TTI must be less than 85, as defined in
49 CFR Part 572, Subpart F. Torso contact during rebound is acceptable
and need not be measured.

\(d\) [Pelvis]{.underline}: If the pelvis of an ATD at any seat place
impacts seat and/or adjacent structure during testing, pelvic lateral
acceleration injury criteria must be substantiated by dynamic test or by
rational analysis based on previous test(s) of a similar seat
installation. Pelvic lateral acceleration must not exceed 130g. Pelvic
acceleration data must be processed as defined in FMVSS Part 571.214,
section S6.13.5.

\(e\) [Body-to-Wall/Furnishing Contact]{.underline}: If the seat is
installed aft of a structure such as an interior wall or furnishing that
may contact the pelvis, upper arm, chest, or head of an occupant seated
next to the structure, the structure or 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 the actual
structure be covered with at least two inches of energy absorbing
protective padding (foam or equivalent) such as Ensolite.

\(f\) [Shoulder Strap Loads]{.underline}: Where upper torso straps
(shoulder straps) are used for sofa occupants, the 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.

\(g\) [Occupant Retention]{.underline}: All side-facing seats require
end closures or other means to prevent the ATD's pelvis from translating
beyond the end of the seat at any time during testing.

**2. General Guidelines**

\(a\) All seat positions need to be occupied by ATDs for the
longitudinal tests.

\(b\) A minimum of one longitudinal test, conducted in accordance with
the conditions specified in § 25.562(b)(2), is required to assess the
injury criteria as follows. Note that if a seat is installed aft of
structure (e.g., an interior wall or furnishing) that does not have a
homogeneous surface, an additional test(s) may be required to
demonstrate that the injury criteria are met for the area which an
occupant could contact. For example, different yaw angles could result
in different injury considerations and may require separate tests to
evaluate.

-   For configurations without structure (e.g., wall, bulkhead)
    installed directly forward of the forward seat place, Hybrid II ATDs
    or equivalent must be in all seat places.

-   For configurations with structure (e.g., wall, bulkhead) installed
    directly forward of the forward seat place, an SID or equivalent ATD
    or more appropriate ATD must be in the forward seat place and a
    Hybrid II ATD or equivalent must be in all other seat places.

-   The test may be conducted with or without deformed floor.

-   The test must be conducted with either no yaw or 10 degrees yaw for
    evaluating occupant injury. Deviating away from the no yaw condition
    must not result in the critical area of contact not being evaluated.
    Allowing the test to be conducted at 10 degrees yaw will permit many
    occupant injury tests to be considered the structural test as well
    and is considered acceptable since an exemption is sought in lieu of
    compliance with part 25. Note that this condition does not provide
    relief from the requirement that torso restraint straps, where
    installed, must remain on the occupant's shoulder during the impact
    condition of § 25.562(b)(2).

\(c\) For the vertical test, conducted in accordance with the conditions
specified in § 25.562(b)(1), Hybrid II ATDs or equivalent must be used
in all seat positions.

**FCAA POSITION:**

Open.

**APPLICANT\'S POSITION:**

Open.

**CONCLUSION:**

Open.

**Attachment 2**

> ***(DRAFT)***
>
> ISSUE PAPER

+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+
| **PROJECT:**                            | **ITEM:** CI-X             |
+-----------------------------------------+----------------------------+
|                                         | **STAGE:** 2               |
+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+
| **REG. REF.:** §§ 21.16, 25.562, 25.785 | **DATE:** March 31, 2003   |
+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+
| **NATIONAL**                            | **ISSUE STATUS:** OPEN     |
|                                         |                            |
| **POLICY REF.:**                        |                            |
+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+
| **SUBJECT:** Dynamic Test Requirements  | **BRANCH ACTION:**         |
| for Single Place Side-Facing Seats      | ANM-115, AAM-630, ANM-102N |
+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+
|                                         | **COMPLIANCE**             |
|                                         |                            |
|                                         | **TARGET:** Pre-TC         |
+-----------------------------------------+----------------------------+
|                                         |                            |
+-----------------------------------------+----------------------------+

Proposed Special Condition

\*\*\*\*\*\*\*\*\*\*\* NOTE \*\*\*\*\*\*\*\*\*\*\*

> Do not revise header information above directly as this may cause
> field code references to be lost! Always use the \"Edit Variables\"
> selection from the \"Edit\" Menu. This text will not print!
>
> \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*

**STATEMENT OF ISSUE:** Side-facing seats are considered a novel design
for transport category airplanes that include Amendment 25-64 in the
certification basis, and were not considered when those airworthiness
standards were promulgated. The FAA has determined that the existing
regulations do not provide adequate or appropriate safety standards for
occupants of single-place side-facing seats. In order to provide a level
of safety that is equivalent to that afforded to occupants of forward
and aft facing seating, additional airworthiness standards, in the form
of special conditions, are necessary.

This issue paper will be used to establish the minimum acceptable
testing and human injury criteria that will be applied to single-place
side-facing seat certifications. This information will complement the
criteria given in § 25.562 and can be used in developing Special
Conditions in accordance with § 21.16.

**BACKGROUND:** 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 § 25.561, and added a new § 25.562 that required 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.

This issue paper is intended to provide a standardized methodology to
address all single-place side-facing seat installation approvals in the
future. Since the regulations do not address side-facing seats, these
criteria should be documented in Special Conditions.

**FAA POSITION:** In addition to the airworthiness standards in
§§ 25.562 and 25.785, the following proposed special condition provides
injury criteria and installation/testing guidelines that represent the
minimum acceptable airworthiness standard for single-place side-facing
seats:

**1. The Proposed Injury Criteria**

\(a\) [Existing Criteria]{.underline}: All injury protection criteria of
§ 25.562(c)(1) through (c)(6) apply to the occupant of a side facing
seat. Head Injury Criterion (HIC) assessments are only required for head
contact with the seat and/or adjacent structures.

\(b\) [Body-to-Wall/Furnishing Contact]{.underline}: The seat must be
installed 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]{.underline}: Thoracic Trauma Index (TTI) injury
criterion must be substantiated by dynamic test or by rational analysis
based on previous test(s) of a similar seat installation. Testing must
be conducted with a Side Impact Dummy (SID), as defined by 49 CFR Part
572, Subpart F, or its equivalent. TTI must be less than 85, as defined
in 49 CFR Part 572, Subpart F. SID TTI data must be processed as defined
in Federal Motor Vehicle Safety Standard (FMVSS) Part 571.214, section
S6.13.5.

\(d\) [Pelvis]{.underline}: 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]{.underline}: 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.

**2. General Test Guidelines**

\(a\) One longitudinal test with the SID ATD or its equivalent,
undeformed floor, no yaw, and with all lateral structural supports
(armrests/walls).

Pass/fail injury assessments: TTI and pelvic acceleration.

\(b\) One longitudinal test with the Hybrid II ATD, deformed floor, with
10 degrees yaw, and with all lateral structural supports
(armrests/walls).

Pass/fail injury assessments: HIC; and upper torso restraint load,
restraint system retention and pelvic acceleration.

\(c\) Vertical (14 G\'s) test is to be conducted with modified Hybrid II
ATDs with existing pass/fail criteria.

**FCAA POSITION:**

Open.

**APPLICANT\'S POSITION:**

Open.

**CONCLUSION:**

Open.