Guidelines for AIRCRAFT BOARDING CHAIRS



A Technical Paper on the Design of Chairs Used Primarily for Enplaning

and Deplaning Physically Handicapped Passengers



Prepared for:



ARCHITECTURAL AND TRANSPORTATION BARRIERS COMPLIANCE BOARD



1111 18th Street, N.W.



Suite 501



Washington, D.C.  20036-3894



(202) 653-7848 (voice or TDD)



Prepared by:                 



AMERICAN INSTITUTES FOR RESEARCH   



45 North Road



Bedford, MA 01730



(617) 275-0800



PREFACE



Aircraft boarding chairs, wheelchair-like devices used to transport

disabled passengers onto airplanes, have been cited for safety and

other problems.  The Architectural and Transportation Barriers

Compliance Board (ATBCB), in an effort to gain more information,

distributed a survey on boarding chairs through the Federal Register

(49 Fed Reg 36210, September 14, 1984).  Passengers using aircraft

boarding chairs responded by reporting complaints regarding safety,

comfort, independent mobility, and personal dignity. In response to

these problems and complaints, the ATBCB sponsored research to examine

aircraft boarding chairs.  The objective of the research was to develop

non binding guidelines aimed at improving aircraft boarding chair

design and use.  



The ATBCB retained the services of a human factors  engineering

consulting firm to perform the research and develop  performance

specifications.  A human factors team, which  included human factors

engineers and a physician and physical  therapist specializing in

wheelchair design and prescription,  analyzed existing aircraft

boarding chairs in both their static  state and during use.  This

approach permitted a comprehensive  evaluation of the physical features

of aircraft boarding chairs and  the "human-machine" interactions.  A

draft advisory standard was  reviewed by the ATBCB, industry experts,

boarding chair  designers, airline personnel, airport operators and

aircraft  boarding chair users prior to publication for public comment. 



On May 15, 1986, the ATBCB published a proposed  advisory standard in

the Federal Register (51 Fed Reg 17762),  for the purpose of eliciting

public comment.  Shortly after  publication in the Federal Register, a

copy of the proposal was  sent to each of a group of reviewers

(rehabilitation engineers,  designers, air carriers, physical

therapists, consumers, and governmental agencies) previously identified

by the contractor  and to members of the National Transportation

Facilitation  Committee (NTFC) subgroup on Air Travel Accessibility.  

Together these groups include a broad cross-section of air  carriers,

wheelchair designers and manufacturers, rehabilitation  engineers,

government officials, and disabled consumers.  In addition, copies were

sent to the committee developing  wheelchair standards convened by the

American National  Standards Institute (ANSI) from the Rehabilitation

Engineering  Society of North America (RESNA), past participants in

the  Access to the Skies conferences, Air Transport Association  (which

represents major carriers), Regional Airline Association  (which

represents most of the small regional carriers), Airline  Pilots

Association of Flight Attendants, National Air Carrier  Association,

Society for Advancement of Travel for the  Handicapped, Paralyzed

Veterans of America, national Council of  Independent Living Centers,

Transport Canada, and  Rehabilitation International USA among others.  



The ATBCB received a total of five substantive comments  addressed to

Docket Trans-1-86. An analysis of the public  comments and associated

changes to the May 15, 1986,  published draft are provided in the

sections which follow.  On March 9, 1987, the Board's Standards

Committee  reviewed the final report submitted by the contractor,

including  the incorporation of comments submitted by those who 

responded to the Federal Register publication.  The Committee 

recommended that the product of this research be published as  a

technical paper.



The contents should be viewed as the  product of the contractor,

distributed by the Board in the  furtherance of its technical

assistance mandate, not to be  interpreted as a determination by the

Board as to the suitability  of specific provisions.         



ANALYSIS OF PUBLIC COMMENTS    



In the May 15, 1986, Federal Register publication of the  proposed

advisory standard, the ATBCB included an invitation  for general

comments on the technical provisions and specific comments on the

following four issues:    



1. Use of the 99th percentile male weight, as opposed to the  95th

percentile male weight, in guidance associated with load  bearing;    



2. The cost impact of the proposed advisory standard in terms  of new

designs, existing boarding chair modifications and  boarding chair

replacement;    



3. Whether the final advisory standard, when published and  provided for

public information, should also be included in the  Code of Federal

Regulations even though it will be a non- binding standard;    



4. The size of the area on which the downward force is  applied to the

seat [see guideline 4.1(d)].  



The limited number of comments was interpreted as a sign  of concurrence

with the proposed technical provisions given that  a large number of

comments typically signals disagreement and



controversy over the published material.  In fact, the majority of 

comments received supported the development of the document  and

concurred on technical details.  The Eastern Paralyzed Veterans

Association (EPVA) stated, "In general terms as this  standard relates

to the nature of our membership, we believe  that it is an excellent

document" EPVA cited eleven (11) specific  items it considered strong

points.  One respondent who also is  a physically handicapped traveler

stated, "I was impressed with  the comprehensive, competent effort

evident in the draft."  



It is worth noting that, although copies of the proposal were  sent to

major airlines, aircraft manufacturers, and especially  aircraft

boarding chair and wheelchair manufacturers, no comments were received

from any of these organizations.  



Specific comments (paraphrased) and associated analyses  by the human

factors engineering consultant are presented  below.  Comments received

which affirmed the contents of the guidelines have not been

addressed.                        



PUBLIC COMMENTS AND ATBCB RESPONSES    



One respondent suggested that, instead of transferring the  disabled

person laterally, a transfer from a ninety degree angle  would be less

taxing and safer for aircraft personnel.  This suggestion relates to

transfer procedures versus boarding chair  design.  The suggested

transfer method would require an area  wider than the boarding chair in

front of the passenger's seat  and involves standards for seating

access, an aircraft cabin  design topic not addressed in the

guidelines.  No change was  made to  the technical provisions.    



Another respondent recommended use of the 95th (as  opposed to the 99th)

percentile male weight in guidelines  associated with load-bearing

capacity.  Since only one  respondent among all reviewers recommended

use of the 95th  versus the 99th percentile value, the 99th percentile

male weight  value was retained in the load-bearing capacity guidelines.



A representative of the Minnesota State Council for the  Handicapped

recommended inclusion of the advisory standard  in the Code of Federal

Regulations even though it would be a non-binding standard.  The ATBCB

has determined that  publication in the Federal Register and

codification in the Code  of Federal Regulations could be misinterpreted

as giving the guidelines more weight than they are intended to have and

has  instead decided to publish a technical paper as a source of 

information only.  



Another respondent suggested modifying Appendix draft test  procedure

(ISO/173 SCI/WIC-220) to include a note stating that  domestic

standards should be in effect within the year and will supersede the

draft standards at that time.  In concurrence,  reference to the

RESNA/ANSI wheelchair standards was added  to Appendix A.  



One respondent pointed out that several federal government 

organizations. e.g., IRS and Social Security, use the word  "disabled"

exclusively to mean unable to earn an income by reason of impairment. 

The respondent suggested that it may  increase consistency in federal

terminology to substitute the  word "handicapped" instead.  The term

"disabled" had originally been selected because many individuals find

the term  "handicapped" demeaning.  However, the reason cited for

using  the term "handicapped" was deemed justified and the change  was

made.  Another respondent felt that the topic of boarding chair  comfort

should be given additional emphasis in the design  guidelines.  While

improvement in comfort is intrinsic to many of  the guidelines, such as

recommendations on seat padding and  use of armrests, the purpose of

the guidelines is to improve  safety and accessibility.  Therefore, no

additional comfort  performance guidelines were considered warranted

or  appropriate.  



One respondent felt that folding backrests should be  recommended.  The

document identifies the need for easy  transfers and suggests folding

features where needed to meet  the performance criteria [see 4.3(i)]. 

The technical provisions  have not been made more specific since they

are limited to  performance guidelines.



Concerning Section 4.7(b), another respondent felt that the  wording

indicated that four separate restraints should be used  and believed

that four separate restraints would not be cosmetically acceptable to

many passengers.  The respondent  suggested stating that do not

necessarily have to be four  separate belts.  No change was made to the

technical  provisions since they specify restraint performance by

virtue of  support functions, not a belt design.  It is preferred to

allow  designers to develop their own design solution which meets the 

four stated restraint functions.  



One respondent believed that USDOT regulations have been  in effect

since 1979 which prohibit the carrying of disabled  passengers up and

down stairs for access to the aircraft. it was  found that, while the

regulation cited requires airport operators  to provide certain

boarding equipment, it does not prohibit  carrying passengers up stairs.

Therefore, no changes were  made to guidelines which reference aircraft

boarding via stairs.        



Regarding the four specific issues identified by the ATBCB  for comment,

issues 1 & 3 were addressed above.  A single  comment which concurred

with the document's contents regarding issue 4 was the only response to

that question.  No  respondents addressed the cost impact issue; no

boarding chair  manufacturers commented on any portion of the

proposal.  



Technical assistance with respect to this and related  subjects is

available by writing to Office of Technical and  Information Services,

ATBCB, 1111 18th Street N.W.,  Washington, D.C.  20036-3894 or by

calling (202) 653-7848.                         



CONTENTS   



INTRODUCTION    



I. THE PURPOSE OF THE TECHNICAL PAPER                 



1.  Why Boarding Chair Design Guidelines were Created 



2.  Application of the Guidelines                      



3.  Scope of the Guidelines                            



4.  How the Technical Paper is Organized                 



II. PROJECT BACKGROUND  



1.  The Need for Boarding Chair Guidelines              



2.  The Role of the ATBCB



3.  How this Technical Paper was Developed            



4.  The Needs of Passengers and Airline Personnel      



5.  Goals for Boarding Chair Designers and Airlines                                 



TECHNICAL PROVISIONS    



PART 1 DEFINITION OF TERMS                              



PART 2 HUMAN AND ENVIRONMENTAL FACTORS  



2.1  Physical Characteristics of Users  



2.1  The Aircraft Boarding Environment    



PART 3 GUIDELINES FOR BOARDING CHAIR OPERATION  



3.1  Mobility  



3.2 Safety  



3.3 Maintenance  



3.4 Storage    



PART 4 GUIDELINES FOR DESIGN FEATURES   



4.1  General Physical Characteristics  



4.2  Seating  



4.3  Backrests  



4.4  Headrests  



4.5  Armrests  



4.6  Gripping Surfaces  



4.7  Restraints  



4.8  Footrests    



APPENDIX A:  ADOPTED ISO PROCEDURES    



APPENDIX B:  GUIDELINES FOR TRAINING                                                         

           



INTRODUCTION                                



I. THE PURPOSE OF THE TECHNICAL PAPER    



This technical paper is intended to promote improvements  in the

accessibility of facilities and services to disabled people.   As

described in Section II, this particular document is part of a larger

effort by the ATBCB to provide technical assistance on  eliminating

architectural and transportation barriers encountered  by disabled

people.  The ATBCB's mechanism for accomplishing  this goal with

respect to aircraft boarding chairs is the  publication of guidelines

on their design and use.    



1. WHY BOARDING CHAIR DESIGN GUIDELINES WERE CREATED  



The guidelines presented in this paper do not constitute a  legally

enforceable regulation. Neither are they necessarily  exhaustive or

definitive.  Rather, since the ATBCB does not have legal jurisdiction

over such devices, this technical paper was  deemed the most effective

and appropriate means to promote  and facilitate improvements in

aircraft boarding chair design and  use.  The need for some form of

guidance arises from safety  problems and complaints regarding these

chairs.  The technical  provisions provide a range of guidance that is

intended to help  eliminate the most common problems encountered by

disabled  passengers and airline attendants.    



The development of the guidelines is the result of several  years work

in the aircraft boarding chair area.  Over several  years,

representatives of the government, airlines, airport  operators,

aircraft boarding chair manufacturers and wheelchair  users have

organized and worked together in an effort to identify  problem areas

and improve boarding chair design and use. 

  

 Many of the reported problems appear to be due to design  while others

appear to be due to improper use of the devices.   The latter may be

due to improper or inadequate training. 

 Therefore, the technical paper addresses both of these areas.   



2. APPLICATION OF THE GUIDELINES    



Aircraft boarding chair designers and specifiers should find  the

comprehensive design guidance useful.  It can be utilized as  the basis

for detailed design criteria or specifications to develop  new designs,

or enhance an existing one, or to develop product  specifications and

evaluation checklists.  Aircraft boarding chair  design is an

optimization problem that requires tradeoff analysis  so the guidance

is performance-oriented rather than prescriptive  to allow for

creative, trade-off solutions.  Data on desirable  design features are

based on user testing and preferences to  which the designer or

specifier may not otherwise have access.  

 

 The technical provisions identify performance requirements  for

boarding chairs that the purchaser should look for in devices  on the

market and identifies how a specific feature should  operate or be

designed to satisfy passenger and attendant  needs.  It can also be

used to improve boarding chair  maintenance and airline attendant

training.  The technical provisions may also help to evaluate boarding

chairs currently in  use and help determine whether they should be

replaced with  improved products.  The guidelines may also be useful

when  designing training courses.    



In addition, aircraft designers may find the technical  provisions

useful in designing seating layouts and interior  configurations which

facilitate boarding chair use.        



3. SCOPE OF THE GUIDELINES    



The technical provisions apply to aircraft boarding chairs.   They are

not intended to be applied directly to devices used for  functions

other than aircraft boarding, such as on-board chairs used for

in-flight mobility or wheelchairs used for mobility within  the airport

terminal.  However, some features desirable for  boarding chairs may

also be desirable for on-board chairs and,. where an on-board chair is

used for boarding and deplaning,  the technical provisions are

applicable.    



The scope of the guidance provided in this technical paper  is broad

enough to accommodate the many types of aircraft  boarding chairs

currently in use.  The broad scope also  supports the objectives of

sustaining or increasing the number  of boarding chair manufacturers. 

The technical provisions are  not intended to restrict design freedom. 

The performance-based guidelines are designed to eliminate safety

hazards while  permitting different and creative solutions to the

engineering  problems.   



Not all of the guidance provided will or can be applied to a  single

type or design of aircraft boarding chair.  This is due to  the fact

that such chairs have competing design requirements such as maximum

adjustability and mechanical simplicity.  It is  the responsibility of

the user to interpret the guidelines and  determine where specific

provisions apply.  Technical assistance  to supplement the technical

paper and provide guidance for  interpretation and implementation will

be available through the  ATBCB.        



4.  HOW THE TECHNICAL PAPER IS ORGANIZED    



This document is divided into six parts.  Sections I and II  provide

background information regarding the function of the  guidelines and

the topic of architectural barriers and aircraft boarding chairs.  The

technical provisions themselves are in four  parts.  Part 1 provides a

list of key terms; Part 2 defines the  physical characteristics of the

users, both the passenger and attendant, and the environment in which

the boarding chair is  used.  The remainder of the provisions, Parts 3

and 4, consist of  detailed guidelines for boarding chair design. 

Appendix A  provides the version of the International Standard

Organization  (ISO) test procedures which were used to define whether

a  specific performance criterion was met.  Appendix B contains 

guidelines on personnel training and defines who should be  trained, how

often training should be conducted, and the extent  of training

needed.                



II  PROJECT BACKGROUND    



1.  THE NEED FOR BOARDING CHAIR GUIDELINES    



There is a continuing need to provide disabled people with  equal access

to places and services.  With improved recognition  of rights of

disabled people, many public works and services  have been modified to

provide access.  However, modifications  have not included provisions

for complete unhindered access to  aircraft.  While many airport

terminals now provide accessible  restrooms, electric doors and ramps,

few aircraft manufacturers  have designed accessible restrooms and

airlines have not  specified seating configurations with wide aisles to

allow  standard wheelchair access.                



Because a standard wheelchair will not fit down the airplane  aisle (17"

wide), it is necessary that some other device be used  for boarding and

deplaning disabled passengers.  It would seem  that wheelchair

manufacturers solved the problem already by  designing aircraft

boarding chairs (examples of existing boarding  chairs are shown in

figure 11-1). However, aircraft boarding  chairs do not fulfill all of

the needs of the passengers and  attendants. Reports of accidents and

near accidents involving  existing aircraft boarding chairs have

indicated that  improvements in aircraft boarding chair design are

needed.  Guidelines that provide for the basic needs of aircraft

boarding  chair users are essential in eradicating existing

architectural  barriers for disabled persons in air transportation.     



2.  THE ROLE OF THE ATBCB    



Under section 502 of the Rehabilitation Act of 1973, as  amended, the

Architectural and Transportation Barriers  Compliance Board (ATBCB) is

vested with various functions  relating to transportation barriers

confronting persons with  disabilities (29 U.S.C. 792). First, the

Board is directed to  investigate and examine alternative approaches to

eliminating  transportation barriers, particularly with respect to

public  transportation (including air, water, and surface

transportation  whether interstate, foreign, intrastate, or local), and

to determine  what measures are being taken by Federal, State, and

local  governments and public and private agencies to eliminate such 

barriers (id. at 792 (b)(2) and (3)).    



The Board is also required to "prepare plans and proposals  for . . .

actions as may be necessary to the goals of adequate  transportation .

. . for handicapped individuals, including proposals for bringing

together in cooperative effort, agencies,  organizations, and groups

working toward such goals or whose  cooperation is essential to

effective and comprehensive action"  (id. at 792(c) (3)).    



The Rehabilitation, Comprehensive Services, and  Developmental

Disabilities amendment of 1978 (P.L. 95-502)  amended section 502 to

provide the ATBCB with new functions  regarding transportation

barriers.  Under the Amendments, the  Board is required to "Insure [sic]

that public conveyances,  including rolling stock, are readily

accessible to, and usable by physically handicapped persons" (29 U.S.C.

at 792(b)(8)).    



The amendments also require that the ATBCB, in  consultation with other

concerned agencies, to "develop  standards and provide appropriate

technical assistance to any  public or private activity, person or

entity affected by regulations  prescribed pursuant to this title [Title

V of the Rehabilitation Act]   with respect to overcoming . .

.transportation. . .barriers" (id. at  792(d)(3)).





Since the ATBCB had received a number of reports of  accidents or near

accidents involving the use of aircraft boarding  chairs, the board was

concerned with the lack of standards that would ensure adequate safety

features, equipment and  procedures necessary to secure the safe

enplaning and  deplaning of physically disabled passengers by airport

operators  and airline carriers.  This concern led to further research

and the  initiative to develop this technical paper.    



3. HOW THIS TECHNICAL PAPER WAS DEVELOPED    



The development of this document was based on human  factors engineering

research and analysis.  The human factors  engineering research

conducted to develop the technical provisions included full

consideration of the product users  (disabled passengers and airline

attendants).  Research methods  included a complete literature search,

static evaluations of the



current product designs, dynamic observations of the products  in use in

their intended environment ( the airport skybridge and  aircraft), an

assessment of the user's physiological needs, and  extensive interviews

with wheelchair users, airline attendants and  boarding chair

designers.    



A set of problems, complaints, and concerns regarding  boarding chairs

was derived from each of the techniques.  For  each of the problems,

complaints, and concerns identified, as  well as for potential problems

not actually observed or reported,  a performance guideline was written

to help alleviate the  problem.  The guidelines were then classified by

topic (aircraft boarding chair feature, documentation issue, or

training concern)  for inclusion in this technical paper.    



Standards or standardized test procedures developed by  industry

consensus groups such as the International  Organization for

Standardization (ISO) or the American National  Standards Institute

(ANSI) have been incorporated where  available and appropriate. 

Preliminary drafts were circulated for  review and comment to the

National Transportation Facilitation  Committee (NTFC) subgroup on Air

Travel Accessibility,  members of the ATBCB, and over 60 reviewers

selected for their  expertise in the subject area.    



4. THE NEEDS OF THE PASSENGERS AND AIRLINE PERSONNEL      



The guidelines address the needs of both disabled  passengers and

airline attendants.  For the passenger, the  boarding chair must

provide adequate body support and  restraint. Typically, a passenger is

seated in the boarding chair  for approximately 5 minutes or less. 

However, under  circumstances when flight changes must be made, delays

occur,  or a standard wheelchair is unavailable, the time spent seated

in  the boarding chair can extend to an hour or longer.  In such cases,

support, ease of body repositioning and passenger independent mobility

are vital.  Regardless of the length of time  spent seated in the

boarding chair, proper support can only be  achieved if the boarding

chair accommodates the size of the  passenger.    



The airlines are concerned not only with the safety and  comfort of the

passenger, but also with the safety and comfort  of the airline

attendant and the ease of use of the aircraft boarding chair.  The

attendant is susceptible to injury if the  transfer is performed

incorrectly. Often, the size of the attendant  in relation to the size

of the boarding chair and passenger makes a proper transfer difficult. 

If the airline attendant must  assume an awkward position while

boarding or deplaning a  passenger, there is potential risk of injury

for both the attendant and passenger.    



5. GOALS FOR BOARDING CHAIR DESIGNERS AND AIRLINES    



It should be the goal of boarding chair designers and  manufacturers to

develop boarding chairs that minimize the  potential for injury and

increase overall comfort without  sacrificing ease-of-use and low

cost.  The airline should select  and purchase boarding chairs that

best suit the needs of the  passengers and attendants and provide

adequate training for  personnel.



This technical paper provides guidelines to help fulfill  these goals.  

                                                

 TECHNICAL PROVISIONS                            



Part 1.  Definition of Key Terms    



Air Carrier Airport:  Airport that serve airlines utilizing aircraft

that  seat fifty or more passengers or receive federal funds for 

terminal facilities. (REF:  49CFR Part 27, Section 27.5)    



Aircraft Boarding Chair:  Narrow, wheelchair-like device used to 

transport non-ambulatory passengers between the airport  terminal gate,

via skybridge or aircraft steps, and the aircraft seat.   



Anthropometric:  Measurement of various human physical traits  such as

size, mobility (range-of-motion) and strength.  



Attendant:  Any individual who participates in the task of  transporting

transferring a passenger; can be an airline  employee, a service

contractor, or a passenger's private  assistant.     



Boarding:  The process of moving a passenger from the  terminal, via a

skybridge or aircraft steps, to the aircraft seat.   The boarding task

incorporates both transporting and  transferring tasks.    



Boarding Chair:  Same as aircraft boarding chair    



Channeling:  A groove used to direct or guide an attached  mechanical

part such as a strap in a specified direction.    



Clarity of Function:  Degree to which it is obvious how a  boarding

chair feature should be used.    



Deplaning:  The process of moving a passenger from the aircraft  seat,

via a skybridge or aircraft steps, to the airport terminal.  The

deplaning task incorporates both transporting and transferring.    



Extended Periods (period of time):  A duration of 15 minutes or  longer.



5th Percentile Female:  An adult woman who is smaller than  95% of the

female population for a given parameter.    



Independent Mobility:  The capability of moving without the help  of

another person while using a manual device.    



ISO (Test) Dummy:  A test apparatus, developed by the  international

organization for Standardization (ISO), used as an  equivalent human

load for wheelchair testing.  The dummy is  equivalent to a male

weighing 220 lbs with a standing height of  78 inches and is

constructed according to Draft International  Standard ISO-DIS 7176/11. 



Lifting Device:  Device used to elevate disabled passengers to  the

aircraft cabin entrance level, eliminating the need to use a  stairway

(REF:  49 CFR Part 27, Subpart D, Section 27.71 (a)(2)(v))    



95 Percentile Male:  An adult man who is larger than 95% of the  male

population for a given parameter.    



Quadriplegia:  Paralysis involving the trunk and all limbs.    



Repositioning:  Shifting body position to redistribute weight.   



Restrain:  To restrict body movement or keep the body under  control.   



Skin Ulceration:  Breakdown of skin tissue caused by prolonged  external

pressure on the skin.





Skybridge:  Ramp that connects the airplane cabin door to the  airport

terminal gate entrance. 



Standard Loading Mass:  A regulation soccer ball (European  Football)

filled with lead shot of approximately 3.0 mm to 4.0 in  diameter to a

specified weight (ISO definition).    



Standard Loading Pad:  A rigid circular object 100 mm in  diameter whose

face has a convex spherical curvature of 300  mm radius  with a 12 mm

front edge radius.  Pad should be  faced with a layer of hard polyether

foam 2mm thick (ISO  definition). 



Storage Location:  A place within the terminal (not on the  aircraft)

where boarding chairs are kept when not in use.    



3.0 Safety Factor:  A 200% increase in load capacity to ensure  safety. 

To calculate load capacity with a 3.0 safety factor,  multiply the

baseline load by 3.0.  This safety factor is generally  accepted by

wheelchair manufacturers and the ISO.     



Transfer:  The process of lifting up and moving a passenger  from one

seated position to another.    



Transfer Board:  Accessory used to bridge the gap between the  aircraft

boarding chair and aircraft seat.  Passenger slides over  the board

thus reducing the time the passenger is held by the  attendants.      



Transport:  The process of moving a passenger in a boarding  chair

whether it be by pushing, pulling or lifting.    



Part 2.  Human and Environmental Factors    



2.1 Physical Characteristics of Users    



Designing aircraft boarding chairs requires close attention to  the

physical dimensions and biomechanical capabilities (together  termed

anthropometric) of the people who will use the devices:   the disabled

passenger and the airline attendant.  The aircraft  boarding chair, the

disabled passenger, and the airline attendant  together form a system

which has several physical  interrelationships or interfaces. Designing

the interfaces which  meet the anthropometric requirements of the users

will help  assure that the "Boarding Chair" system is easy and safe to 

operate.    		 	



Body Dimensions    



The boarding chair user population includes both adult  males and

females.  Therefore, the physical characteristics of the  aircraft

boarding chair must accommodate a large range of human dimensions and

physical capabilities which varies from  small females to large males. 

It is normal in engineering and  design to develop a product to meet the

anthropometric requirements of 95% of the user population;   meeting a

larger range which approaches 100% is usually  infeasible or

unwarranted.  The range of anthropometric data is  normally defined in

terms of percentiles.  To match the  anthropometric of approximately 95%

of the aircraft boarding  chair user population, one needs to find

minimum and maximum  anthropometric values (for a given parameter) for

the 5th  percentile female and 95 percentile male, respectively.    A

percentile is determined as follows:    



For a 5th percentile female dimension, 5 out of 100 females  would be

smaller in that dimension.    



The result of calculating parameter values for the 5th percentile 

female and 95th percentile male is a practical range of physical 

characteristics that can be used as a basis for design. This  approach

optimizes a design but may not meet as effectively the  needs of 5% of

the (small) females and 5% of the (large) males  in the user

population.  It is not the intent to exclude any portion  of the

population.  In practice a "5th - 95th" design usually accommodates

more than 95% of the user population.    



Anthropometric data is presented in Figures 2-1 and 2-2 for  use in

designing aircraft boarding chairs.  Figure 2-1 provides  overall

dimensions for the 5th percentile female and the 95th percentile male. 

Figure 2-2 provides hand, arm, foot and head  dimensions for the same

anthropometric range.  This data is  referenced from the "Human Factors

Design handbook." Additional data that relates specifically to the

aircraft boarding  chair design problem is presented below.  The data

includes  body weight and strength.  Other anthropometric data can be 

found in NASA Reference Publication 1024, "Anthropometric  Source Book,

Volume I:  Anthropometry for Designers."  



Body Weight    



Maximum body weight determines the maximum load or stress  on the

components and frame of the aircraft boarding chair:  A  99th

percentile male weighs 241 lbs.  A weight of 241 lbs. should be used as

a design basis with appropriate consideration  given to the safety

factors in design, since there are still many  people who weigh more

than 241 lbs.  Clearly, an aircraft boarding chair can not be designed

to accommodate the  heaviest person imaginable. Nonetheless, the

designer is  advised to maximize weight bearing capacity in aircraft

boarding chair design.  The 99th percentile weight has been used, as 

opposed to the 95th percentile (which is 224 pounds), since the 

potential for damage or collapse of the aircraft boarding chair is  a

significantly more serious safety hazard than the failure of  other

design features that affect comfort more than safety.    



Physical Strength and Endurance    



Figure 2-3 illustrates the lifting strength and pushing force  capacity

of the 5th percentile female.  A 5th percentile female in  a standing

position is capable of lifting 74 pounds from a starting point 15

inches off the ground.  The same individual can  apply a horizontal

force of 24 pounds to a handle device which  is 33 inches off the

ground.  Strength declines continuously after  initial application to

the point that strength is reduced to 25%   of the original maximum

capacity after four minutes of force  application.  This data suggests

that many disabled passenger  transfers will require two or more

attendants or that only  relatively strong attendants will be capable

of performing all  aspects of the boarding task which culminates with a

transfer  (involving a lift).  For this reason, strength and endurance 

requirements of the transporting task should be minimized in  any given

design.  Attendant training should incorporate  procedures for

transporting heavy passengers. Physical Disability Aircraft boarding

chairs should be designed for passengers with  maximum disability. 

Therefore, a person with quadriplegia  involving total loss of arm and

leg control and weakened head  control should be considered as the

design basis.   Designs  should also consider the potential needs of

individuals with  missing limbs or deformities and/or involuntary

movements. 

  

 2.2  The Aircraft Boarding Environment    



Aircraft are not optimized for wheelchair access.  Aircraft cabin 

interiors and aisles, in particular, are designed to be narrow so  that

the cabin can accommodate the maximum number of  people.  The narrow

aisle is one of the major complicating   factors in disabled passenger

access.  The other major factor is  the continuing lack of skybridge

connections to airplanes at  many smaller airports and with many

commuter airlines,  requiring the use of a stairway to board an

airplane.  Stairways  are still used at some airports to board even

large, wide-body  airplanes; especially during rush periods of the day

when there  are not always enough gates with skybridges available. The 

U.S. Department of Transportation requires that operators at  federally

assisted airports assure that adequate assistance is  provided for

enplaning and deplaning handicapped persons.  Boarding by jetways and by

passenger lounges are the  preferred methods for movement of

handicapped persons  between terminal and aircraft at air carrier

airports; however,  where this is not practicable, operators at air

carrier airport  terminals shall assure that there are lifts, ramps, or

other suitable  devices not normally used for movement of freight that

are  available for enplaning and deplaning wheelchair users [49  C.F.R.

27.71 (a) (2) (v)].  A lift eliminates the need to carry the  passenger

up a stairway. However, lifts are not consistently  available and

stairways are often used.    



Since stairways will continue to ba common means of aircraft  access for

the indefinite future, aircraft boarding chairs must be  designed so

that they are safe to use on stairways.    Stairway operation is the

most critical mode of aircraft boarding  chair use.  In stairway

operations, the dropping or tipping  hazard is greatest for the

passenger, while the physical exertion  requirement for attendants is

also at its peak.  Such operations  also cause the disabled passenger

the greatest discomfort and  anxiety.  Boarding chair design and

boarding methods must be  implemented which minimize the risk of

injury.    



Skybridges are the preferred boarding approach.  There are two  basic

types of skybridges: stationary and movable.  Stationary  skybridges

have a fixed floor inclination.  Movable skybridges  have vertical and

horizontal adjustability and can result in a  steeper overall floor

incline of up to 7.5 degrees (13%).  This  slope angle of the connecting

ramps between skybridge sections  may be as high as 13 degrees (25%). 

The movable skybridge  is also narrower to enhance its movability but

satisfies the width  requirement for wheelchair access. 

  

 Passengers who use wheelchairs normally travel down the  skybridge in

standard-sized wheelchairs.  At the base of the  skybridge they are

transferred into an aircraft boarding chair and  brought onto the

airplane.  When a skybridge is used for  access, the only potential

architectural barriers outside the  aircraft are the inclination of the

skybridge floor and the gap at  the threshold between the aircraft

cabin door and the skybridge.   A steep skybridge floor inclination

requires extra strength to  control the wheelchair or boarding chair (in

the case that the  boarding chair is used from the terminal gate

point).  Brakes are  required in case there is a need to stop and hold

the boarding  chair on the incline.  The threshold gap may require

backward  tilting of the aircraft boarding chair to overcome it and has 

implications in wheel and caster design.   



The aircraft, depending on make and cabin configuration, may  present an

access problem. This is particularly true for small  commuter

aircraft.  Although the cabin doorway and entranceway are wide enough

to permit easy entry into the  aircraft with a boarding chair, the

aisles between seats are  narrow.  The narrow aisle width increases the

danger of a passenger's limbs getting wedged between the boarding

chair  and an aircraft seat.  The narrowness of the aisle also

presents  a problem when the passenger must be moved from the  boarding

chair to the aircraft seat.  The attendants are required  to reach

around the seated passenger to lift him or her into the  aircraft

seat.  Space for the attendants' arms in the area between  the aircraft

seats and the boarding chair is tight.  Therefore, in  cases where the

aircraft seat armrest does not pivot out of the  way, transferring is

further complicated.  A fixed armrest  necessitates that one attendant

reach over the back of the  aircraft seat and lift the passenger up

over the armrest.  This presents risk to the passenger and attendant. 

Reaching  around the back of the seat does not permit the attendant to 

obtain secure grip of the passenger and the approach is  generally less

gentle and comfortable for the passenger.



The  attendant also risks back injury due to poor posture during 

lifting.      



Part 3.  Guidelines for Boarding Chair Use    



3.1  Mobility    



(a)  Number of Attendants.    



When boarding, a minimum of two airline attendants should be  present to

transport a passenger.  If the passenger is particularly  heavy or the

attendant(s) is not physically strong, the transport  task may require

more than two attendants.    



(b)  Time.    



Once the boarding chair is at the aircraft entrance, the time to 

prepare the boarding chair for passenger seating should be less  than

two minutes.    



(c)  Attendant Posture.    



Transfers should not require the attendant to bend in awkward 

positions.  Figure 3-1 illustrates the proper body posture that the 

boarding chair should permit.    



(d)  Passenger Posture.    



The boarding chair design should ensure proper passenger  posture. 

Figure 3-1 illustrates a proper body posture for  passengers seated in

a boarding chair.    



(e)  Boarding Chair Orientation.    



The boarding chair should not require tilting for movement  unless

negotiating curbs, stairs, or similar barriers.  



(f)  Turning.    



The occupied boarding chair should be able to turn within the  confines

of the boarding environment and the aircraft cabin  layout shown in

figure 3-2.  Turning should not require tilting or  rocking the

boarding chair.    



(g)  Ease of Movement.    



The force required to push and turn (on a level surface) a  boarding

chair occupied by a 241 pound passenger (the 99th  percentile male)

should not exceed 24 pounds (the maximum force which can be exerted by

a 5th percentile female).    



(h)  Ease of Transfer.    



The boarding chair should be designed to facilitate the use of a 

transfer board.    



(i)  Vibration.    



The boarding chair should be free of noticeable vibration when  moving

on a smooth surface such as a carpeted aircraft aisle.   



(j)  Alignment.    



When the boarding chair is pushed in a straight line it should  continue

to track accurately along that path.    



(k)  Independent Mobility.    



Boarding chairs designed to be used in the airport terminal  should

provide manual independent mobility for passengers who  have manual

independent mobility in their own wheelchairs.    



(l)  Locking Mechanisms.    



Wheel locks should be accessible to the passenger.  To the  extent

possible, the force required to engage/disengage locks  should not

exceed that which a passenger with limited hand  and/or upper extremity

function can exert.  Wheel locks should  hold the boarding chair

(occupied by the 100 kg ISO dummy)  motionless when placed at a 13

degree angle (maximum  skybridge ramp angle) and faced either uphill or

downhill.   Wheel locks should not cause tire damage or excessive

wear.    



3.2  Safety    



(a)  Posture    



The boarding chair should be designed so that the passenger  and

attendant maintain proper posture during the passenger  transport and

transfer.  (see figure 3-1).    



(b)  Support.    



The boarding chair should provide adequate passenger body  support for

the full range of users, including quadriplegics and  amputees.  The

passenger should not require supplementary  seating or restraints

outside those that are part of the boarding  chair.       

  

(c)  Restraints.    



The restraining system should prevent the passenger from falling  out of

the boarding chair under all circumstances.    



(d)  Hinges and Locking Mechanisms.      



Hinges and locking mechanisms on movable and removable  components

should be located where they cannot pinch or  damage the attendant's or

passenger's skin or clothing.    



(e)  Releases.    



Releases (for components such as locks and footrests) should  be located

where they cannot be accidentally activated  (released).  Where

accidental activation is possible and a safety concern, a guarded

release or two-step release procedure  should be used.   



(f)  Rounded Edges.    



The boarding chair design should incorporate rounded edges on  all

components to avoid injury to passenger, attendant, or  passerby and to

protect the physical environment (stairway, skybridge, airplane).      



3.3  Maintenance    



(a)  Preventive Maintenance.    



Preventive maintenance tasks, task frequency, and specific  procedures

should be specified by the manufacturer.   Maintenance task

descriptions should include inspecting,  cleaning, and performing minor

repairs.  All parts requiring  maintenance should be easily accessible. 



(b)  Cleaning.    



Surfaces which come in contact with the passenger and  attendant should

be cleaned easily and cleaned as frequently as  deemed appropriate by

the airline.  Boarding chair hardware components should be cleaned on a

regular basis as deemed  appropriate by the manufacturer.  All surfaces

and mechanisms  requiring cleaning, as specified by the manufacturer,

should be  cleaned by airline personnel or the responsible contractor.  



(d)  Inspection.    



Parts which are subject to wear should be easily accessed and  inspected

on a regular basis. Inspection procedures should not  require special

knowledge, skills, tools, or equipment and should  be performed by

airline personnel or the responsible contractor. 



(e)  Replacement of Parts.    



Damaged or missing parts which are not part of the chair frame  (main

structure) should be available for purchase and  replaceable according

to paragraph 3.3(g).        



(f)  Tools.    



Only common tools should be required to perform maintenance  tasks. 

Specialized or one-of-a-kind tools should not be required  for

maintenance tasks performed by airline personnel.    



(g)  Spare Parts.    



Components of the boarding chair which are easily replaced  (such as

fasteners and bearings) and not part of the chair frame  (main

structure) should be made readily available as spare parts  stocked by

the manufacturer and at least one other source.   Available spare parts

should be easily replaced.      



3.4  Storage    



(a)  Damage Resistance.    



Boarding chairs should be of durable construction to avoid  damage

during storage.  Fabric on the chairs should be  resistant to tears,

stains, or fading which may occur during  storage. 



(b)  Compactness.    



When possible, boarding chair design should utilize adjustable  features

which maximize compactness during storage.      



(c)  Collapsibility.    



Collapsible boarding chairs should lock in the collapsed position.  

Collapsible chairs should be easy to move when in the  collapsed

position.  Reconfiguring the chair for use should be achieved easily

and quickly.    



(d)  Removable Items.    



To avoid loss or theft, removable components should be  attached to the

chair during storage, though not necessarily in  their operational

configuration.  Configuring components for  storage should be performed

easily and quickly.  Small parts  such as nuts and bolts) should remain

fastened to the chair  during storage.    



(e)  Loose Items.    



Loose items (such as restraints) should have a clear method for  storage

so they do not get lost or damaged.    



(f)  Time Requirements.    



Time required to prepare the boarding chair for storage should  not

exceed two minutes.  



Part 4.  Guidelines for Design Features    



4.1  General Physical Characteristics    



(a)  Overall Dimensions.    



The boarding chair should, to the extent possible, be sized to 

comfortably accommodate 95% of the passenger population (see  section

2.1), but should not exceed the dimensional limitations  of the

aircraft on which it is to be used.  The narrowest part of  the aisle

(17") is generally at the aircraft seat armrest height but  wide

-------------------.    



(b)  Overall Weight.    



Overall weight should be minimized.    



(c)  Load Capacity.    



The boarding chair should support 723 lbs (the 99th percentile  male

body weight with a 3.0 safety factor).    



(d)  Static Stability.    



The boarding chair should not structurally deflect (bend), rock or  tip

from the placement of a 241 lb vertical, downward force at  any point

on the seat.  The object should be a rigid circular  object 4 inches in

diameter (see ISO Definition for Standard  Loading Pad).  The boarding

chair should also meet the  requirements for static stability as defined

in Draft International  Standard ISO/Dis7176/1 (See Appendix A).    



(e)  Static and Impact Strength.    



For boarding chairs, the following sections of Draft International 

Standard ISO TC173/SCI N3,"Static and Impact Strength Test",  should be

applied:    



(1)  1-5.7 (Background Test Information)    



(2)  6.1.1 Armrest Downward Static Load Test    



(3)  6.1.2 Push handle(s) Downward Static Load Test    



(4)  6.1.3 Footrest Downward Static Load Test    



(5)  6.1.4 Tipping Levers Downward Static Load Test    



(6)  6.1.5 Hand Grip Static Load Test    



(7)  6.1.6 Armrest Upward Static Load Test    



(8)  6.1.7 Footrest Supports Upward Static Load Test    



(9)  6.1.8 Push Handle(s) Upward Static Load Test    



(10)  7.0  Conditions for Acceptance After Static Strength Tests     



(11) 8.1.1 Seat Impact Strength    



(12) 8.1.2 Backrest Impact Strength    



(13) 8.2.1 Drop Test Impact Strength    



(14) 8.2.2 Rolling Test Wheels and/or Castors Impact Strength  For all

above tests, the 220 lb ISO dummy should be used (See  Appendix A for

test procedures).    



(f)  Adjustable.    



Where practical, adjustable features should be used to increase  safety,

support and comfort. The features should be easy to  adjust and should

not sacrifice chair and passenger stability. 

 

(g)  Removable Parts    



To avoid loss, the number of removable parts should be  minimized, or if

possible, eliminated. 

  

(h) Construction Materials.    



Construction materials should be durable, damage resistant, fire 

retardant and low and high temperature resistant.    



(i)  Protective Features    



The boarding chair should have protective features (such as  rounded

edges and bumpers) to avoid damage to the aircraft  boarding

environment.    



4.2  Seating    



(a)  Function.    



Seating should accommodate 95% of the passenger population  and should

be designed to facilitate transfers by providing  unobstructed access

for lifting.    



(b)  Dimensions.    



Seating should be sized according to the dimensions given in  figure

4-1.    



(c)  Strength.    



Seats should support a weight of at least 723 pounds (the  weight of the

99th percentile male with a 3.0 safety factor) and  should meet the

requirements in guideline 4.1 (e).    



(d)  Location.    



Seat surface height (compressed) should be 17-19 inches to  match the

height of aircraft seats and should incline 5 degrees  to increase body

restraint (See figures 4-2 and 4-3).    



(e)  Shape.    



Seat shape should provide passenger body support and  restraint and

distribute body weight evenly  to avoid the risk of  skin ulceration. 

Seat shape should not hinder passenger transfers.  



(f)  Material.    



Seat material should be water repellent, stain resistant, fire 

retardant, non-abrasive, durable, cleanable, and aesthetic.   Based on

ISO research, the cushion should be constructed of a good quality foam

at least 2 inches thick with a indentation load  deflection (ILD) of 70

as measured by ASTM Designation D  1564-71, "Standard Methods of

Testing Slab Flexible Urethane  Foam."  The cushion cover should be a

color which is low in  heat absorption so that the cover does not

overheat (if left in the  sun) and cause thermal trauma to passengers. 

  

(g)  Texture.    



Seat material texture should not be so rough (high friction) that  it

hinders passenger body positioning.    



(h)  Cushioning.    



Cushioned seating should be provided to distribute body weight  evenly

and to protect against skin ulceration.  Seat cushions  should not

strike the back of the passenger's knee, thereby avoiding blood flow

restriction and cause nerve damage (See  Figure 4-4).    



(i) Construction.    



Seats should keep their shape, even after extended use.    



4.3  Backrests    



(a)  Function    



Backrest should support the passenger and aid in restraining  the

passenger's torso and be comfortable.    



(b)  Dimensions.    



Backrests should be sized according to dimensions given in  figure 4-1. 

Note:  Where boarding chairs must be carried up  stairways (i.e., at

locations which are not air carrier airports) the  backrest height

should be a minimum of 38 inches.  Refer to  Section 4.4, Headrest.    



(c)  Orientation.    



The angle between the base of the backrest and the seat should  be 90

degrees.  for comfort purposes, the middle to upper  portion of the

backrest may be gradually reclined as shown in  Figure 4-1.    



(d)  Strength.    



Backrest should meet the requirements in guideline 4.1 (e).



(e)  Shape.    



Backrests should be constructed to provide support, aid in  restraining

a passenger, and avoid interference with passenger  transfers.    



(f)  Material    



Backrest material should be water repellent, stain resistant, fire 

retardant, non-abrasive, durable, cleanable, and attractive.  for 

aesthetic purposes, cover material used on the backrest should  be

coordinated with the material used on the seat.    



(g)  Texture.    



Backrest cover material should not be so rough (high friction)  that it

hinders passenger body positioning.    



(h)  Cushion.    



The backrest cushion should provide a firm surface.  However,  cushion

firmness should not compromise skin protection.    



(i)  Folding.    



Folding backrests should collapse in a manner which does not  hinder

transfers. Hinging mechanisms should automatically lock  in place when

the backrest is fully extended and folded.





(j)  Adjustment Mechanisms.    



The method of operation of backrest adjustment mechanisms  should be

readily apparent and easy to perform.    



4.4  Headrests    



(a)  Function.    



Headrests should be provided to support the head, preventing  the head

from falling back or to the sides.    



(b)  Dimensions.    



Headrests should be dimensioned to accommodate 95% of the  user

population.  (see figure 2-2)    



(c)  Location    



Headrests should support the passenger's head at ear level.



(d)  Strength.    



Headrests should support a force of 30 lbs (the average weight  of a

male's head with a 3.0 safety factor) applied in the aft and  both

lateral directions and should meet the requirements in  guideline

4.1(e).    



(e)  Material.    



Headrest material should be water repellent, stain resistant, fire 

retardant, non-abrasive, durable and cleanable.    



(f)  Ease of Transfer.    



The position of the headrest should be one which does not  require an

attendant to assume an awkward body position (with  poor leverage)

during a transfer.  (e.g., the headrest could fold  or retract out of

the way).    



4.5  Armrests    



(a)  Function.    



Armrests should be provided to support the passenger's arms.   Armrests

should provide a firm gripping or resistance surface for  passengers to

push against when repositioning themselves and  to assist in protecting

the passenger from injury.    



(b)  Dimensions.    



Armrests should be sized to accommodate 95% of the  passenger population

for the dimension of arm length.  (see  figure 2-2).     



(c)  Location.    



Armrests should be located at the seated elbow resting height  optimized

for 95% of the passenger population.  The armrests  should be

adjustable over the range of 7.0-12.0 above the seat  surface.    



(d)  Strength.    



Each armrest should support 241 lbs (the weight of the 99th  percentile

male) and meet the requirements in guideline 4.1(e).  



(e)  Material.    



Armrest material should be durable, non-slip, water repellent,  stain

resistant, fire retardant and cleanable.    



(f)  Orientation.    



Armrest should be oriented to provide vertical and lateral arm  support.



(h)  Adjustability/Removability.    



Armrests should be removable or fold away.  Adjustable, folding,  and/or

removable armrests should have locking and quick  release mechanisms

that are accessible to the passenger.  



4.6  Gripping Surfaces    



(a)  Function.    



Clearly identified gripping surfaces should be provided for  attendants

to hold onto during the transport of a passenger.     



(b)  Number.    



Gripping surfaces should be provided where needed for  pushing, pulling,

and lifting, as determined by defined operating  procedures.  As many

gripping surfaces as possible should be  provided to adapt to a variety

of boarding chair-to-attendant  orientations.  As a minimum, the number

of gripping surfaces  should fulfill the requirements of paragraph

4.6(d).    



(c)  Dimensions.    



Gripping surface size should accommodate the 95th percentile  male hand

for width and length and the 5th percentile female  hand for diameter

(see Figure 2-2).  Physical clearance between the gripping surface and

surrounding boarding chair parts  should be provided for the 95th

percentile male hand.    



(d)  Location    



As a minimum, gripping surfaces should be provided on the  boarding

chair frame near the shoulders and feet of the seated  passenger.  The

pushing surface should be located at the attendants' standing elbow

height, 40-42 inches optimized for  the 50th percentile of the total

user population.  (see Figure 2-1)    



(e)  Material.    



Gripping surface material should be textured, water repellent,  stain

resistant, temperature resistant, fire retardant and durable.  Gripping

surface materials should be firmly attached to avoid  turning,

slipping, or accidental removal.    



(f)  Strength.    



Each gripping surface should be capable of supporting (for all  possible

load applications) the total weight of the boarding chair  plus 723 lbs

(the 99th percentile male weight with a 3.0 safety  factor).  Each

gripping surface should meet the requirements in  guideline 4.1(e).    



(g)  Body Posture    



The attendants should not be required to assume awkward  positions (such

as twisted back or bent wrists) while pushing or  lifting the chair.   



(h)  Skin Protection.    



The attendant's hands should be protected from contact with  surrounding

surfaces such as aircraft walls, seats, doors, or  stairways while

holding onto the gripping surfaces.    



(i)  Clarity of function.    



Gripping surfaces should be readily apparent to the attendant.   



(j)  Chair Stability.    



When the boarding chair, occupied by the 5th percentile female  or 99th

percentile male, is pushed, pulled or lifted in the  direction of

travel by the gripping surfaces, the boarding chair should not tip or

fall to either side.    



4.7  Restraints    



(a)  Function.    



Restraints, such as safety belts, should be used to secure a  passenger

in the boarding chair and ensure the safety of the  passenger during

transportation.    



(b)  Placement.    



Restraint should be designed to securely support:    



(1)  Torso    



(2)  Pelvis    



(3)  Knees    



(4)  Feet.    



Restraint placement should ensure that the passenger's body is 

centralized and stabilized in the boarding chair.  Restraints  should

be attached rigidly to the boarding chair frame and held



in their intended position of use by their method of attachment, 

channeling or some other means.  Pelvic straps should be  attached at a

30-45 degree angle from the seat connected at the  seat and back joint

to hold the pelvis against the back of the  boarding chair (see Figure

4-5)    



(c)  Material.    



Material should be stain resistant, non-abrasive, fire retardant,  water

resistant, durable, cleanable and attractive.    



(d)  Texture.    



Material used should not cause skin irritation or promote skin 

ulceration at contact points.  

 

 (e)  Fastening Mechanisms.    



Restraint connect and release mechanisms should require as  few steps as

possible to be secured effectively (1-2 steps is  optimum).  Fastening

mechanisms should connect and release



quickly and be within the passenger's reach.  Fastening  mechanisms

should be able to be released by individuals with  impaired strength

and reduced hand and arm dexterity.   



(f)  Adjustability.    



Restraining devices should be easily adjustable in size to  accommodate

the body dimensions of passengers ranging from  the 5th percentile

female to the 95th percentile male (see Figure 2-1)  Once a restraining

device has been adjusted to fit a  passenger, any excess portion of a

strap should not interfere  with boarding chair operation and create a

potential hazard for tripping or catching.  



(g)  Clarity of Function.    



Restraining device method of use and connection should be  obvious. 

Incorrect use should be impossible.  The need for  instructions on use

should be minimized.  Coding techniques, such as color or shape should

be used to simplify the  identification of interacting parts (see

Figure 4-6).    



(h)  Strength.    



Restraining devices should withstand a force of 723 pounds (the  weight

of the 99th percentile male with a 3.0 safety factor) as  shown in

Figure 4-7.    



(i)  Storage.    



When not in use, restraining devices should not interfere with  chair

movement.  Restraining devices not in use for a particular  passenger

should not interfere with operation or cause discomfort to the

passenger.  The method of restraint storage  should be obvious and

efficient.





4.8  Footrests.    



(a)  Function.    



Footrests should be provided to support and stabilize the  passenger's

feet and legs during transport.  The footrest should  prevent the

passenger's foot from slipping off the footrest when



tilted back and should prevent the passenger's feet from sliding 

sideways or forward under all circumstances.    



(b)  Dimensions.    



Footrests should be a minimum of 4.3 inches in width for each  foot. 

The depth of the footrest should maintain a secure and  comfortable

foot posture for extended periods.  (See Figure 2-2).     



(c)  Location    



The contact point between the foot and footrest should be  located at an

adjustable distance over the range of 16.0 to 29.0  inches from the

front of the seat as shown in figure 4-8.    



(d)  Orientation    



Footrests should allow the passenger's foot and lower leg to rest  in

the position typical to that person (this may not be directly  side by

side).    



(e)  Adjustability.    



Footrests should be easy to adjust.    



(f)  Strength    



During operation, a collision between the footrest and a  surrounding

object should not cause passenger injury, alteration  of passenger leg

position, or damage to the boarding chair.  Footrests should meet the

requirements in guideline 4.1(e).      



(g)  Support.    



Footrests should provide complete support to the passenger's  feet and

lower legs.  Foot supports should prevent the  passenger's feet from

slipping beneath the boarding chair under all operating conditions.    



(h)  Material    



Footrest material should be durable, resistant to cracking  chipping, or

splintering, temperature resistant and cleanable.   



(i)  Padding    



Footrests should not promote skin ulceration even after  prolonged

contact.  Padding should be used, as necessary, to  provide a

comfortable contact surface; particularly in the area of the lower

leg.    



(j)  Ease of transfer.    



Transfer of passengers should not be impeded by footrest size  or

location.  If necessary, footrests should be retractable or  swing away

to ensure attendant and passenger safety.    



Appendix A:  Adopted ISO Test Procedures    



Note:  Test procedures have been paraphrased and adapted for 

applicability to aircraft boarding chairs.  Although several testing 

protocols were considered practicable, the ISO protocol has  been

designated to provide testing consistency and to facilitate  product

performance comparisons.  For comparison with  comprehensive wheelchair

testing procedures, see the complete  Draft ISO Test Procedure

Document, ISO/173 SCI/WC1-220 and similar domestic version pending

publications by RESNA/ANSI.



A1  Scope    



This part of ISO 7176 specifies a method for determining the  static,

impact and fatigue strength of manual wheelchairs.    



A2  References    



ISO 6440 Wheelchairs - Nomenclature, Terms and Definitions  ISO/DIS

7176/11 "Wheelchairs - Part II:  Test Dummies"    



A3  Definitions    



For the purpose of the part of ISO, 7176, the definitions of ISO  6440

apply.    



A4  Test Principles    



The Static Tests are intended to assess the static strength of the 

wheelchair and its component parts under the high levels of  loading

that occur only occasionally.  The evaluation of boarding chairs does

not require destructive  tests.  



A5  General Conditions    



The following conditions shall be established and recorded  during the

testing of boarding chairs in accordance with this  evaluation

protocol.    



A5.1  The boarding chair shall be fully equipped for normal use. 



A5.2  If the wheelchair has pneumatic tires, the air pressure in  them

shall be adjusted in accordance with the directions set  forth by the

manufacturer/supplier.  If a pressure range is specified, the highest

recommended pressure shall be selected.   



A5.3  The seat unit, if adjustable, shall be set to correspond to a 

natural sitting posture.  The leg support/footrest, if adjustable, 

should be positioned 50 mm above the ground.  Horizontally



adjustable seat units shall be set at their mid position.  If 

adjustable, the slope of the seat relative to the horizontal shall  be

as close as possible to 4 degrees, and the slope of the backrest

relative to the vertical shall be as close as possible to  10 degrees. 

The angle between the seat and leg support shall  be as close as

possible to 10 degrees.  The angle between the  seat and leg support

shall be as close as possible to 90  degrees.  Wheelchairs with

fore/aft adjustment on the rear  wheels shall be adjusted at their

middle position.    



A5.4  The wheelchair shall be inspected to insure that:    



(1)  All supporting wheels are contacting the ground    



(2)  All wheels meet the specified alignment tolerance limits    



(3)  The folding mechanism (if it exists) fully and readily deploys  (a

wheelchair with a folding x-frame should fold under the  influence of

gravity when laid horizontally)    



(4)  All detachable components detach and reassemble readily     



(5)  The tires are firmly seated in their rims    



(6)  There are no loose spokes (if existing)    



A5.5  The dimensions shall be recorded before the  commencement of the

tests and again after all tests have been  completed.  Before any

measurements are taken, any free play  in the structure of the boarding

chair which might affect the  measurements should be taken up by

loading the wheelchair  with appropriate ISO dummy (Refer to ISO/DIs

7176/11).  Measurements should be made from well-defined points on the 

structure to give maximum indication of any deformation that  might

occur as result of the tests.    



A5.6  Immediately before commencing each test procedure the  components

for which the test was conducted shall be  thoroughly inspected.  Any

visible defects shall be noted, and  any defects considered

sufficiently significant as to affect further  testing shall, if

possible, be rectified.    



A5.7  References to an appropriate standard test dummy shall  mean a

test dummy of 220 lbs constructed according to the  details in ISO/DIS

7176/11 of this standard.    



A6.1.1  Armrests Downward Static Load Test  



A downward force of 147ON, at 45 degrees, shall be applied to  the upper

surface of both armrests simultaneously with a load  fixture at the

front of the horizontal surface of both armrests.   For tests on chairs

with removable armrests, check that armrests  remove and reinstall

correctly.    



A6.1.2  Push handle(s) Downward Static Load Test    



A vertical downward force of 197ON shall be applied to the  push bar or

both push handles simultaneously.  If the  wheelchair is equipped with

a push bar, the force is applied to  the center of the push bar.  If

there are separate push handles  the force is applied simultaneously by

placing a bar over the  push handles and applying the force, using the

standard loading pad, midway between the handles.    



A6.1.3  Footrest Downward Static Load Test



A downward force of 132ON shall be applied once vertically  downward, to

the center of each footrest plate.  If the footrest is  of one-piece

construction, the specified force shall be applied to  its center,

using the standard loading pad.  If the wheelchair has  adjustable knee

angle leg rests they shall be adjusted as close  as possible to 90

degrees between the seat and leg rest.   Adjustable height footrests

shall be extended to their lowest  position of 50 mm above the ground,

whichever is higher.  If the  footplate is adjustable, adjust to 90

degrees to the leg reference  plane.  During this test, slippage of

adjustment shall not exceed  25 mm.  The movable caster shall be placed

in its normal  trailing position.    



A6.1.4  Tripping Levers Downward Static Load Test    



A vertical downward force of 147ON shall be applied to each  tipping

lever in turn.  The force shall be applied over a length of  50 mm at

the end of each tipping lever.  This applies to any rearward projection

that might be used as a foot tipping lever.  



A6.1.5  Hand Grip Static Load Test    



A force of 160ON shall be applied once to each handgrip using a loading

fixture.  The force should be applied for 10 seconds  without the

handgrip pulling off.    



A6.1.6  Armrests Upward Static Load Test    



An upward force of 160ON shall be applied at 10 degrees to the 

vertical, outward to the side. Force shall be applied to the  underside

of each armrest simultaneously, in the middle of the armrest, using 50

mm webbing or strap material.  For test on  chairs with removable

armrests check that armrests remove and  reinstall correctly.  Note: 

Vertically pivoting or non-locking armrests should pivot or remove

easily and will therefore pass  the test with regard to safety

considerations.    



A6.1.7  Footrest Supports Upward Static Load Test    



A vertical force of 43ON shall be applied to both footrest support 

structures simultaneously (or most forward projecting part), using  50

mm webbing or strapping material.  If the footrest is  constructed in

one piece, the specified force shall be applied to  its center.  Note: 

Adjustable knee angle leg rests shall not be  tested.    



A6.1.8  Push Handle(s) Upward Static Load Test    



A vertical upward force of 850N shall be applied to the push  handle(s)

simultaneously using 50 mm webbing or strapping  material.  If a push

bar is used, the load is applied to the center.





A7  Conditions for Acceptance after Static Strength Tests    



The boarding chair shall be visually inspected after static  strength

tests are completed noting the following:    



(1)  Any fracture of any member, joint or component;    



(2)  Any fracture, cracking or discontinuity of the surface finish  of

the structure;    



(3)  Free play or loosening in the frame structure, folding  mechanism,

armrests, footrests, brakes, wheels or wheel  bearings and any other

component of the wheelchair, greater  than that noted in the initial

inspection;    



(4)  Any deformation or maladjustment of any part of the  wheelchair, or

of its attachments, that will adversely affect its  function;    



(5)  Wheel alignment shall be remeasured and recorded noting  the

tolerances given;    



(6)  The boarding chair dimensions shall be remeasured and  recorded. 

These dimensions should be within 3 mm of the  pretest dimensions

recorded;    



A pass/fail disclosure shall be made based on the visual  inspection and

the alignment and dimensions noting the  tolerances given.    



A8.1.1  Seat Impact Strength    



The seat shall be tested for impact with the Standard Loading  Mass

filled with a weight of 25 kg.  During these tests the  wheelchair

shall be secured to the floor to prevent folding for movement.  With

the wheelchair in the normal open position, the  weighted mass shall be

dropped onto different areas of the seat  from a height of 200 mm.  The

specified impact tests are as  follows:    



(1)  Drop mass onto center of the seat.    



(2)  Drop mass onto each front corner of seat as near to the  corner as

possible.  If the wheelchair has removable armrests  they shall be

removed.    



A8.1.2  Backrest Impact Strength    



The backrest shall be tested for impact with the Standard  Loading Mass

with a weight of 25 kg.  The specified impact  tests for the backrest

are as follows:    



(1)  Suspend the standard loading mass as a pendulum such  that it

impacts the center top edge of the backrest from the front  at a 45

degree angle.  The standard loading mass shall be  dropped from a

height of 500 mm.          



(2)  Suspend the standard loading mass as a pendulum such  that it

impacts each back frame member at the top, from the  front at a 45

degree angle.  The standard loading mass shall be dropped from a height

of 500 mm.  During this test the boarding  chair shall be secured to

the floor to prevent folding or  movement.   



A8.2.1  Drop Test Impact Strength    



(1)  With all folding mechanisms (if existing) deployed to the 

ready-to-use condition (open), lift the wheelchair loaded with the 

220lb standard test dummy above a hard, flat surface at a height of 100

mm.  Using a quick release device drop the chair  allowing it to fall

freely under the influence of gravity to impact  the flat surface.  The

wheelchair should be suspended from a  single point so that it is

tilted 10 degrees laterally (side-to-side)  with an inclination 10

degrees aft so that a rear wheel will  contact the floor first.  The

height of the chair should be measured from the floor to the lower

surface of the wheel being  tested.    



(2)  For folding chairs, repeat with an inclination fore 10 degrees  so

that a front wheel strikes the floor first.      



A8.2.2 Rolling Test Wheels and/or Castors Impact Strength    



With the chair unfolded and loaded with the 220 lb standard test  dummy,

the chair is rolled on a straight line path at the velocity  of 1.1

m/sec towards a standardized obstacle, which is securely  fastened to

the floor.  The velocity should be measured by sue  of a standardized

procedure.  The test dummy shall be securely  fastened into the boarding

chair.  If there are removable/adjustable footrests or other

projections they should  be adjusted to the most upward position in

order to clear  obstacles.  If the distance between the floor and

non-removable  structures or footrests is less than the height of the

standardized  obstacle, the maximum possible height object should be

used  and recorded.    Each front wheel or castor should contact the

standardized  obstacle independently.  The impact angle should be 45

degrees  to the long dimension of the standardized obstacles.    



A9.  Conditions for Acceptance after Impact Strength Tests    



The boarding chair shall be visually inspected after impact  strength

tests are completed.  A pass/fail disclosure shall be  made based on

the criteria to be determined by the ISO.    Appendix B:  Guidelines

for Training    



B1  Training Course Responsibility    



Airlines or responsible contract personnel shall conduct training 

courses.  The airline will ensure that contract personnel conduct 

adequate training and will be ultimately responsible for training 

content, frequency, and adequacy.    



B2  Frequency of Training.    



The airline or responsible contract personnel shall train all  personnel

who will perform disabled passenger transports with  aircraft boarding

chairs before they are allowed to perform the boarding task on the

job.  Refresher courses shall be taught  when different equipment is

acquired, new staff are hired, and  routinely, according to an

established schedule.    



B3  Level of Training.    



All attendants shall successfully perform a passenger transport  and

transfer using both a skybridge and stairway to gain access  to the

airplane.    



B4  Training Course Content    



Training courses shall include the material covered in guidelines  on

passenger services, transfers and stairways.                  



Effectiveness of Passenger Services.    



Training courses shall include the following topics to reduce the 

likelihood of passenger injury:



  

 (a)  Maintain proper attitude toward the passenger to avoid 

mistreatment.    



(b)  consult with the passenger to identify the best method for 

transferring.    



(c)  be aware of the risk of injury.    



(d)  Obtain the owner's chair during layovers if at all possible. 



(e)  Minimize the numbers of transfers per passenger.    



(f)  Restrain the passenger firmly, but not so tight as to cause  injury



(g)  Take caution against legs and feet becoming dislodged  from the

support and getting caught on corners, seat braces or  seats.     



(h)  Avoid pressure sores; allow the passengers to stay in their  own

wheelchairs (that is specifically padded for them) for as  long as

possible.    



(i)  Know where the movable armrests are located on the  aircraft.    



(j)  Know where the boarding chair can be parked (greatest  percent

incline without danger of brakes not holding).           



Passenger Transfers.    



Training courses shall include the following information to  reduce the

likelihood of passenger or attendant injury:    



(a)  Consult with the passenger on the best way to accomplish  transport

procedure.    



(b)  If possible, use a seat with a movable armrest.    



(c)  Do not lift a person who is too heavy for your strength.   



(d)  Stand with feet 12 - 18 inches apart, lift from the knees and  not

the back by keeping the back as straight as possible and  stand as

close to the passenger as possible.    



(e)  Engage brakes/locks on wheelchair and boarding chair  whenever

making a transfer.   





(f)  Allow the passenger to assist with the lift whenever possible.     



Use of Stairways for Boarding    



Training courses shall include the following information to  reduce the

likelihood of injury:   





(a)  Whenever possible, avoid carrying a passenger up stairs.   



(b)  At air carrier airports, locate and know how to utilize the 

airport provided lifting device. 

  

 (c)  Before starting, make certain that all restraints are securely 

fastened, especially about the lower extremities that could splay  and

injure the attendant or upset the balance of the boarding  chair.    



(d)  Place the less experienced attendant at the foot of the  passenger

and the more experienced attendant at the shoulders.   



(e)  Take a practice run if not fully familiar or comfortable with  the

layout.  Practice with a heavy staff member.    



(f)  Keep the passenger informed at all times as to the progress. 



(g)  Make sure hands and gripping surfaces are not wet or  slippery.   



(h)  Rest at each step to preserve stamina.    



(i)  do not wear baggy clothing which could get caught.  Wear non-slip

footwear, such as rubber-soled shoes.    



(j)  Keep the boarding chair tilted back slightly but as  horizontally

straight as possible.  Even the slightest sideways  tilting can

jeopardize control.        





.TCEL.

.

