Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 203
Design of Aircraft Interior
Swen I. Scha~ch*
FUNCTIONS AND PERFORMANCES OF Al:RCRAw INTERIOR
Means of transport serve not only to convey passengers from a place of departure
over a certain distance to a place of destination. During the time of travel, further functions
and performances must be performed:
accommodation in passenger cabin;
protection of passengers from harmful impact;
serving of food;
removal of waste, etc.; and
entertainment.
With respect to these~further functions, special demands are made on commercial
aircraft. Because of the high cost of investment, the operators aim to put the aircraft to
maximum use. This is achieved by the adaptability of the means of transport and a wide
range of services offered. However, the scope of variation is considerably restricted by
specifications meeting physical, economic-technical, and safety requirements. In a way that
does not apply to any other means of transport, the weight of the aircraft is of paramount
importance in economic considerations. Where air traffic is concerned, a particularly carefu!
comparison of the required expenditure with the expected benefit is therefore called for.
The interior furnishing of Airbus cabins includes all components that are insured
between the dividing wall to the cockpit and the pressure bulkhead in the rear fuselage. This
applies to the upper deck, where the passengers are accommodated, as well as to the cargo
. . ~ · . . . - · . ~ · . . ,- . . .
compartments below. The equipment and turnlshmgs include floor panels and carpeting,
lower sidewall panels, upper sidewall panels, overhead stowage compartments, service
channel, ceiling panels, dividers, lighting, air-conditioning outlets (blowers, ventilation grids,
etc.), passenger seats, flight attendant seals, flight attendant work stations, galleys,
lavatories, stowages, passenger information signs, and emergency equipment.
These standard furnishings are supplemented by optional items that are installed at the
request of a particular airline, such as entertainment systems (audio, video), special
provisions for the disabled, sleeping compartments, additional galleys and lavatories, more
comprehensive emergency kits, and stairways.
Due to different arrangements and variations in the number of items, an almost
unlimited variety of interior design configurations is conceivable. This conceivable vanety,
however, is in actuality restricted by the installation conditions, mutual overlappings,
feasibility, installability, and, not least, safety considerations.
Payload Systems, Development and Design, Deutsche Aerospace Airbus, Hamburg, Gerry.
203
OCR for page 204
204
Improved Fire- and Smoke-Resistant Materials
INTERIOR FURNISHING REQUIREMENTS
The aim of aircraft interior design is to create such conditions on board commercial
aircraft as are expected by the passengers. To achieve this objective, many requirements
must be met. These can be subdivided into two categones:
absolutely necessary measures, of vital importance for the passengers; and
options that go beyond mere transportation and serve to create pleasant and
comfortable Raveling conditions.
Looked at another way these requirements can be viewed as including those that
provide for (a) the accommodation of passengers, (b) the protection of passengers, (c)
passenger services, and (~) passenger entertainment.
Accommodation of Passengers
In the past, it was common procedure for aerodynamicists, structure specialists,
system engineers, etc., to build an aircraft to meet the needs primarily of their respective
disciplines. The space available after all systems had been installed was then dedicated to
passengers and furnishings in the most advantageous manner.
After years of this approach, the mind-set of the development engineers has finally
changed, so that accommodating the passengers now means to design the cabin layout
according to the passengers' needs. The cabin layout must allow the demands for maximum
transport capacity (high passsenger density) or maximum comfort (low passenger density) to
be realized. Or, to put it more simply, the means of transport the aircraft and basis for a
slightly graded passenger comfort, is built around the cabin, with due consideration, of
course, to the physical and technical general conditions applying to an aircraft.
In addition to the arrangement of seats, aisles, and escape routes, passenger
accommodation also includes stowage space for hand luggage and a coat room. The
requirements increase with the flight time; if several different climatic zones are traversed,
the corresponding clothing is needed, as are reading matter, work documents, and games to
help pass the time and toiletry articles for refreshment.
On long-distance flights, passengers will ask for facilities for resting. The demand is
due to business executives' needing rest, the transport of disabled, sick, or injured persons,
and the need to accommodate replacement crews. The sleeper seats in common use today
fulfill these expectations only in part. It is for this reason that regular rest compartments are
now offered for crews, for instance.
Protection of Passengers
The aircraft interior in its entirety is laid out to protect passengers during their stay on
board from all impact hazards likely to affect their well-being. The interior furnishing
OCR for page 205
Swen ]. Schaich
205
components and He service systems are therefore laid out not only to make the stay on board
the aircraft pleasant and comfortable but to provide maximum safety from all kinds of risks
both during normal operation and in emergency situations.
The function of the passenger seat is to accommodate the passenger and to afford a
comfortable position for the duration of the flight. A belt serves to retain and keep the
passenger from slipping out of the seat, for instance, during sleep, or in the event of gusts,
turbulences, or rough landings.
Reasonably dimensioned longitudinal and transverse aisles provide for interference-
free traffic during boarding and leaving as well as during flight. These areas also serve as
escape routes.
Stowage compartments above the passenger seats receive the hand luggage. They can
be locked and thus prevent pieces of luggage from dropping onto the passengers in all flight
conditions. Dropping luggage presents a double hazard: injury to the passengers by
immediate impact, or obstruction or blocking of escape routes.
The cabin lighting system can, in connection with an emergency lighting system, help
to avoid all sorts of mishaps.
Since the equipment installed in the galleys and the provisions kept there can have a
considerable weight, dual safety features are installed to prevent their uncontrolled
movement. Throughout the cabin, passenger information signs and light signs are fitted
that either provide information regarding the use of facilities (e.g., pictograms) or request a
certain passenger behavior with the aim of minimizing safety hazards (e.g., "FASTEN SEAT
BELT"~.
The air-conditioning and cabin pressure control system protects the passengers from
the effects of temperature, humidity, and flight altitude and supplies them with breathing air
under conditions that resemble as closely as possible those on the ground.
The entrance areas and the individual classes are separated by dividers that protect the
passengers seated next to the doors from draft and heavy rain entering the cabin while
passengers board and leave the aircraft. By suitable arrangement and design, dividers also
break the long tube of the cabin down into sections that are furnished in accordance with the
respective class standard. Naturally, the dividers are also used for other purposes, such as
promoting the corporate image of the airline, advertizing, providing literature pockets, or the
reception of folding baby bassinets.
All components inside the cabin must be made from approved materials that in case of
fire emit only small amounts of smoke and toxic gases and release only a limited amount of
thermal energy (ATS 1000, Heat Release 65/651. Only such types of construction are used
that, if mechanical failure occurs, do not present an additional risk of injury on account of
the structure of the fracture.
All these functions are dependent on an aircraft structure that allows installation of all
interior furnishing components, as well as the service systems, and that is capable of
supporting all occurring loads.
Naturally, the cabin interior must offer optimal protection for the passengers,
especially under crash conditions and provide means that are absolutely necessary to survival,
such as oxygen systems, emergency exits and emergency escape slides, and fire-fighting
equipment.
OCR for page 206
206
Improved Fire- arm Smoke-Resistant Materials
In summary, it can be said that both active and passive safety measures are taken to
protect the passengers:
Passive features are those that exclude safety hazards (e.g., nonflammable
materials).
Active features are those that reduce or eliminate existing dangers (e.g., fire
extinguishers) .
The interior furnishing components are therefore developed on the basis of the
following criteria:
minimization of risk potential during use, and
provisions to reduce or eliminate the risk of accidents in dangerous situations.
As with all other features, the protection of passengers, in particular from accidents,
can also be extended and improved. However, such schemes make great demands on
engineers from various different technical areas and involve considerable costs for
development, manufacture, and sometimes even use.
Passenger Services
Depending on the specific flight, the passengers will be on board the aircraft for a
longer or shorter period. During this time, at least the minimum needs of the passengers
must be satisfied. But a further spectrum of services that goes beyond the very basic needs
can be offered by the airlines to make traveling an attractive and pleasant experience.
This means not only the serving of food and drinks in varying quality and selection by
attentive flight attendants but also special offers that accommodate individuals' wishes and
needs. Here, emerging trends must be carefully observed and analyzed.
The trends do not develop uniformly. On the one hand, increasingly exclusive service
facilities are demanded and supplied, and on the other hand, inexpensive flights where
service is reduced to the absolute minimum are on the increase.
Because the passengers pay special attention to the services offered, the airlines
formulate particularly varied requirements in order to present their company-specific image.
Passenger Entertainment
Contrary to travel in ground-supported means of transport, flying usually offers, with
the exception of take-off and landing, hardly any welcome diversion. Because the cruise
flight takes place at high altitude, it is difficult to make out any details on the ground, and
vision is often impeded by clouds and mist. In addition, the number of window seals is
relatively small compared to the number of seats per seat row.
OCR for page 207
Swen ]. Schaich
207
Although entertainment is not counted among the basic human needs, because of
worldwide competition, no airline can afford nowadays not to offer these services.
The range of activities offered must be adapted to the operational concept of the
aircraft, the flight time, the image of the airline, and in particular the expectations of the
passengers. It begins with the distribution of magazines and includes audio and video
programs, computer games or complex information systems. These information systems
allow the passengers to use information, work, or entertainment programs according to their
personal preference. As in the serving of food, the trend here is also for "a la carte."
Finally, business executives require communication services. The first and business
classes need to be equipped, besides with telephones, with telefax and data services, to be
supplemented by a secretariat if necessary.
DETERMINING FACTORS
Customer Requests and Feasibility
Every airline faces the problem of maintaining a company-specific image that
uniquely distinguishes it from its competitors. The exterior appearance of the aircraft
provides a first impression of the airlines' corporate image, although in most airports
passengers are checked in via closed passenger bndges.
The interior design of the passenger cabin is also of the utmost importance. It is not
merely a question of realizing the services described above; the airlines are also demanding
ways and means to present their own specific concept of passenger service, which again
means that every airline demands its specifically conceived interior design configuration. For
the aircraft manufacturer, this means that standard solutions are not sufficient to meet the
actual requirements. In other words, the sales prospects are largely dependent on the degree
to which the interior design of the passenger cabin can be adapted to comply with the ideas
and wishes of the customer. The aircraft manufacturer's response is therefore to develop
types of aircraft that permit a high degree of flexibility where configuration and design of the
interior components are concerned. At the same time, the costs for design, manufacture, and
installation are kept within certain reasonable limits in order to achieve relatively short and
scheduled planning and installation periods, and prices that the market will be prepared to
pay.
Types of Construction and Materials
All aircraft components are designed according to lightweight construction principles
because of the direct impact this has on the payload that can be transported. In the area of
OCR for page 208
208
Improved Fire- arm Smoke-Resistara Materials
interior design, the requirements are very complex since several functions must be fulfilled
all at once:
stiffness lightweight construction and high-stiffness materials to achieve a
maximum payload;
safety protection of passengers during flight and in emergency situations, and
moderation of the results of accidents;
design and color design that follows function and is esthetically satisfying, as
well as suitable surface structure and color scheme;
durability resistance to wear in the daily contact with passengers, and resistance
to environmental conditions such as ozone, ultraviolet radiation, cigarette smoke,
and caustic cleaning agents;
hygiene dirt-resistant and easy-care surfaces, resistance to food and kindred
goods (tobacco, alcohol) and compatibility with cleaning agents and
disinfectants; and
· handling design and instructions suitable in form, fit, and function for the
"standard passenger" as well as passengers with special needs, such as disabled
people and children.
In view of the multiple requirements, composite and hybrid structures are of
particular importance. Sandwich structures are of high strength and retain their shape.
Metallic materials are practically no longer used, except for mechanically and thermally
highly stressed components. The primary structures are covered with preformed parts and
then individually finished by means of decor foils, varnishes, or textiles.
Barge components are treated in a similar way. Temperature-resistant layers for
flammable materials improve the resistance to fire (fire-blocking foam layer for seat
cushions).
By embedding materials capable of dangerous fracturing behavior in flexible material,
the risk of injury in the case of accidents is reduced.
Since the passengers have direct access to most of the interior furnishing components,
the wear to which these components are subject (through faulty operation, lack of
understanding, malice, eec.) and the resulting failures and necessary replacement have to be
taken into account. Assembly techniques that allow quick installation with the aid of only a
few tools are therefore very important in order to avoid costly {urn-around times. The
elements used in this connection are mainly of the plug-in, snap, locking, or clamping type,
which calls for a high degree of accuracy to size and inherent stability of the component
parts.
Special measures are taken where resistance to fire is concerned, since a fire puts the
passengers in extreme danger. There are two basic scenarios:
·n-pightire. A fire breaks out during the flight. The fire-fighting provisions must
allow extinguishing the fire or slowing down the rate of propagation so that the nearest
airport can be reached. The main objective must be to maintain the capability to fly. Because
OCR for page 209
Swen J. Schaich
209
of the passengers, the smoke densities and the toxic constituents of the combustion gases
must not exceec! certain values.
Post-crash fire. Emergency landings may be accompanied by fires that are the result
of fuel leaked from the wings or fuselage in the wake of the crash. In this case, too, the fire
propagation must be slowed down to give ad passengers maximum opportunity to leave the
aircraft. However, this is only possible if the passengers are not impeded in their movements
by smoke, toxic combustion products9 or heat.
The technical instructions refer to the release of thermal energy, smoke emission, and
toxic gas components. For this reason, many interior furnishing components have had to be
replaced at great cost with new materials. Materials such as polyviny~chioride (PVC),
acrylonitrile-buladiene-styrene (ABS), or epoxy resins must no longer be used in the cabin;
they have been replaced mainly with polyethenmide (PEI), phenolic resins, and others.
By joint efforts on the part of aircraft manufacturers' interior design departments and
material development departments, new materials that comply with the tightened limit values
have been introduced.
COMMERCIAL ASPECTS
The discussion above may give rise to the impression that everything connected with
the aircraft interior only causes considerable problems or rising costs for manufacturer and
operator alike. It is true that the costs are high. But this impression is put into perspective if
one keeps in mind that the interior design, apart from the service, is the most effective
means an airline has for self-representation; in other words, the interior design is a marketing
instrument of the highest order and must therefore express the airline's excellence.
The manufacturer of interior furnishing components has a sales market that lasts for
the whole utilization phase, a period! of 20 to 30 years. Many components need to be
replaced during this time for reasons of wear, modification, modernization, or conversion.
Proportion of Interior Design Cost;s Compared to Overall Costs
The following data give an idea of the financial dimensions behind an aircraft intenor:
quoted on the basis of the overall manufacturing costs for the Airbus A340 long-range
aircraft;
Interior furnishing of the cabin represents approximately 8.5 percent of the
overall manufacturing costs of the aircraft.
Interior furnishing of cargo compartments represents approximately I.5 percent
of the overall manufacturing costs of the aircraft.
OCR for page 210
210
Improved Fire- arm Smoke-Resistant Materials
In referring to interior furnishing of the cabin and cargo compartments, there are
about 8,000 different assemblies, about half of which must be modified to comply with the
respective wishes of customers.
Effect of Interior Furnishing on Prof.Hability
Like other companies, the airlines must aim to make a profit. With few exceptions
(e.g., cargo airlines), the largest share of their turnover is realized by the transport of
passengers. Depending on the routes, however, earnings can also be improved by
transporting cargo in addition to the passengers' luggage. Principally, there are two ways to
boost turnover:
1.
2.
Increasing the transport capacity. The cabin is bald out to accommodate the
maximum number of passengers. Comfort and service are minor consid-erations.
In order to achieve as nearly as possible full-capacity utilization, low-price
tickets are offered (as, e.g., by charter airlines).
Increasing the transport quality. The passengers are offered services and
conveniences that exceed the usual standard. Here, a group of travelers is
addressed who enjoy special services and are prepared to pay for it.
In all instances, the strategy of the airline must be reflected in the cabin layout. The
custom-designed interior components must be evaluated with a view to profitability, that is,
in terms of additional income to be realized versus the amount of capital investment
necessary to achieve it.
An example of the above may be the transfer of service facilities to the underfloor
area. For example, moving the lavatories to the aft cargo compartment may free additional
space on the main deck for other purposes.
This example shows very clearly that the cabin layout can significantly influence the
profitability of an aircraft.
Conversions or Second Interior Furnishing Sets
Commercial aircraft are high-technology industrial assets that will be in service for
long periods (20 to 30 years). During such a long time, the requirements regarding the
interior furnishing of the cabin are subject to many changes due to such factors as
change of ownership,
modified service concept on account of different flight routes,
altered sociological structure of passengers,
technological progress, and
modernization.
OCR for page 211
Swen J. Schaich
211
The basic cabin layout must therefore incorporate a high degree of flexibility in order
to provide the preconditions required for adaptation to changed circumstances.
The interior furnishing components of an aircraft have a shorter life cycle compared
to the airframe. This results from wear (~e constant use by passengers) and also from
changes In fashion that make the design of a cabin layout appear outmoded. For these
reasons several interior furnishing Sets for the same aircraft may be required during the life
cycle of an airframe. Such conversions need to be performed without major modifications to
the aircraft, that is, without essential alterations to the structure (modular system, families of
parts).
Further Development
On long-distance flights, the cargo compartments cannot be used, or can be used only
in part, for transporting goods because of the payload limitations effective for certain
distances. If an airline wishes then to avoid transporting empty stowage, the utilization
spectrum of the cargo compartments can be enlarged by transferring service facilities for the
passengers from the cabin to the underfloor area. The following several functions may be
realized in the underfloor area:
storage space for the provisioning of food and beverages (catering),
galleys,
lavatories,
crew restrooms, and
passenger lounges.
Through separation of the passenger and service areas, the passengers on the main deck will
no longer be subject to molestations in connection with galleys and lavatories (traffic, unrest,
noises, odors, etc.) and will have greater freedom of movement. This will enhance passenger
transport quality. Passenger transport capacity also can be enhanced by installing additional
passenger seats in the areas that have become available.
This type of utilization extension is the more effective the more service facilities are
moved. The advantages offered by the shifting of cabin functions are not restricted to long-
distance flights. They are always useful where, without changing the outer dimensions of the
aircraft, more space is to be made available for cabin functions. However, cargo
compartments will have to be retained to accommodate the passengers' luggage.
_. . . .
OCR for page 212
Representative terms from entire chapter:
interior design
