International State of the Art

Environment inside aircrafts affect pilots, crew and passengers. Poor conditions cause increasing risks in health and in particular performance of flight crew and cabin crew. "A supportive travel environment should take care for health". This WHO recommendation holds for pilots, crew personnel as well as for passengers, in particular for the aspect of complete physical and mental well-being, however, the current state is far from these recommendations.

Scientific research in this topic is rare. Experimental studies and clinical observations are based on the impact of a single or on the impact of two environmental parameters at best. In the last years effort mainly has been laid on effects of noise or vibration as risks of hearing loss, flight crew performance and speech intelligibility.

However, comfort and well-being appears to be related to a number of environmental characteristics (e.g. noise and vibration, air pollution, humidity, temperature, air draft, pressure, lighting/brightness, speech intelligibility) requiring a multidimensional approach.

Up to now European projects in this context - ASANCA I & II, RHINO (new-conceptions of active interior noise reduction), BRAIN (structural acoustics), IDEA PACI (noise and vibration impact on a virtual passenger) -were restricted to noise and vibration and did not address the multidimensional needs. ASICA and CABINAIR focus on air quality and air conditioning. The technical platform FACE aims to provide advanced know-how for noise and vibration and air-quality control in civil turbofan aircraft cabins.

For combined effects of environmental factors additive, non-additive, multiplicative effects have been proposed in theoretical contributions. The relative importance and interrelationship of different environmental qualities - which may be used for recommendations for a supportive cabin environment - must be investigated and are subject to the current proposal. Environment inside aircrafts with respect to passengers and use of multimedia is planned to be investigated in the new FACE proposal.

Scientific and Technological Approach

In order to carry out research on comfort including subjective well-being, health and performance, a transdisciplinary approach is organised with experienced project participants in the fields of psychophysics, medicine and engineering. The impact of environmental parameters (noise, air pressure etc.) will be investigated by an experimental approach, with special focus on "combined-effects". As the number and levels of independent variables is restricted for an experimental investigation, relevant entities will be revealed in an explorative investigation by narrative interviews and scaling procedures by flight and cabin crew.

Investigations and developments must be carried out on the laboratory level in mock-ups as well as under realistic flight conditions. Since real-flight experiments show obvious limitations and are budget consuming, most of the investigations must be done in representative virtual reality simulations. Perfect mock-ups, which are capable of producing every possible parametric impact on a crew-representative are not available and costly, if newly designed and constructed. Instead of this approach, generic set-ups are developed, which reproduce real-flight data for a limited set of parameters. The similarity and the validation against real-flight data must be evaluated not only by physical measurements but also by established questionnaires and defined semantic differentials.

Segments of real aircrafts are used as mock-ups, already supplied with vibro-acoustic excitations (in a limited frequency range), and can be completed with climate-related means. Additionally, airlines provide in-flight evaluation. The support by airlines ensures the (physical/ environmental and subjective) data acquisition on real flights.

The problem of realizations of long-term exposures in mock-ups is addressed for selected parameters that depend on integral effects. Effects of long-term exposure must be investigated in real flights.

Extensive statistical evaluation of data enables the control of partially correlated parameter sets, which are provided by different mock-up constructions at different sites of partners. Confounding variables are identified and a finite state-space of comfort/ health is described. The selected parameters are reduced to basic factors and requirements for test settings deduced. A preliminary Human Response Model (HRM) will be defined. HRM and Artificial Neural Networks (ANN's), have been investigated during the last decade in numerous publications. They have been tested as controllers, as structural dynamics simulators, or generic interpolators / extrapolators of unknown experimental measures or physical coefficients, with satisfying results. More recently, they were used as a simulation tool to reproduce the generic human response to vibration and acoustic excitation with very promising attainments. ANN has the uncommon ability to learn by examples, and recent studies aim at developing "adaptive nets", that is, systems able to learn "on-line", during the operational life.

Competing Alternative Approaches

The investigation to support healthy and comfortable environment inside aircraft is carried out in a trans-disciplinary multidimensional approach. Alternative procedures generally take into account one or two variables of the environment inside aircrafts (cf. projects cited in International State of the Art). Current measures relate only to e.g. sound and, to some extent, vibration field, and refer to a limited number of subjective parameters. The problem of interrelation between subjective parameters and physical descriptors is not sufficiently described by a one-dimensional approach.

Main Innovations

HEACE is to provide the following innovations:

• definition and identification of the relevant (physical, psychological, physiological, medical) parameter set that describe health, comfort and performance in a supportive travel environment
• definition and implementation of an adequate multidimensional test setting
• upgrading (development) of mock-ups to allow multi-parameter variation
• definition and implementation of a preliminary database from experiments carried out both in-flight and in mock-ups, in operative and laboratory conditions, on different aircraft with homogeneous assumptions.
• definition and implementation of Human Response Models based upon a statistical and an ANN-approach
• definition and implementation of recommendations for improved (cockpit / cabin) work place guidelines
• definition and implementation of standard assessment procedures for cabin / cockpit environment

Scientific and Technological Research Objectives

Fifth R&TD framework programme of EU key action 4 "new perspectives in aeronautics" (Development of Critical Technologies: "Improving environmental friendliness of aircraft", "Cabin environment" and Technology Platform TP 7 "friendly aircraft cabin" aim at "prove the feasibility of achieving the target comfort levels inside the passenger and crew cabins by the integration in a multidisciplinary approach of acoustic / vibration treatments and air distribution design solutions and enabling user friendly application of multimedia services" by means of following main systems and technologies: "active/ passive structure vibration treatment; active/ passive wide band noise reduction of engine and aerodynamic sources; active skins, smart foams, advanced trim panel design; multimedia systems for noise environment improvements; reduction of air contaminants; thermal-hygrometrical comfort.".

Identified research tasks: Advanced methods for prediction and reduction of noise and vibration in the cabin; development and validation of subjective noises and vibration criteria for cabin environments; concepts for enhanced global cabin environments; technologies for cost-efficient cabin humidification and removal of CO2.

HEACE fully fits into these research tasks, in particular in development and implementation of a supportive environment with respect to health, comfort and performance.

HEACE investigates combined effects of e.g., temperature, humidity, air quality, noise and vibration in a transdisciplinary approach. The end-user requirements will be defined and assessed on the basis of the manufacturers and airlines experience to define the parameter sets representing the aircraft architecture (e.g. air conditioning system quality, temperature, humidity) in the current research. Typical flight conditions will be addressed to monitor body and psychological responses, and a preliminary human response model will be defined.

Data for the application and validation of the developed tools will be acquired on real aircraft in flights and available mock-ups. A test run will be performed in order to identify the necessary upgrades and updates of the available test articles, to meet the defined requirements.

Based on the work, described above, HEACE is to develop and validate theoretical methodologies to characterise the human response. A multidimensional statistical analysis as well as ANN structures is employed for development of the HRM.

Finally, tools based on the HRM are developed to support aircraft design and give a-priori the degree of comfort, health etc. related to the supportive environment of a new aircraft. Recommendation and assessment packages for guidelines for a supportive environment (cockpit, cabin) are developed.

Technical Achievements with Respect to Programme Objectives and Priorities

Technical achievements are attained for a supportive travel environment:

• mock up, test setting and design for the investigation of flight crew and cabin crew work places.
• data base of environmental characteristics (e.g. noise and vibration, air pollution, humidity, temperature, air draft, pressure, lighting/brightness, speech intelligibility) in aircraft
• data base of health effects, comfort and performance of flight crew and cabin crew
• definition of a finite, multidimensional state space of comfort and health with a Human Response Models (ANN, statistical approach)
• recommendation for improved flight crew and cabin crew work places guidelines
• development of an assessment tool for supportive travel environment inside aircraft

HEACE meets the "Growth Programme" objectives and priorities, because the proposal:

• contributes to competitiveness and sustainability of European products, addressing the development of an advanced assessment tool, that takes in consideration the need and wishes of the final end-user,
• is a trans-disciplinary project, involving a broad range of different technological and scientific expertise
• develops critical technologies as well as integrates and validates existing knowledge and findings concerning human factors to increase health and safety on board of aircrafts.

The results of HEACE

• assess a tool that is in principle applicable to other transportation means (cars, ships, trains etc.).
• helps to increase the European economic growth by an advanced and competitive product.
• gives European manufacturers the chance to increase their market-share.
• improves the competitiveness of the SMEs by involvement in the project.
• supports the development and implementation of Community policies for the competitive and sustainable development by focussing on human factors in the design process and customers' needs.