A simulator program was carried out with seven (7) Category II qualified commercial airline pilots as subjects. Preliminary results indicate that at the 100 foot decision height, the pilots using the new display were able to monitor the performance of the automatic landing system to the degree of precision specified by the FAA. When a current commercial flight director instrument was used, there was a significant deterioration in the ability of the pilots to monitor autoland system performance.

Additional research is now being planned toward the refinement of the experimental display and to extending its application to terminal area maneuvering and to monitoring landings under Category III visibility conditions (700 feet runway visual range and lower). Applications to unconventional approach operations, such as the steep approach for noise abatement, and the slow speed decelerating approaches characteristic of V/STOL aircraft also will be investigated.

PERFORMANCE-AIR TRAFFIC CONTROLLERS

The demands placed upon the ATC system have multiplied enormously in the past two decades. Figure 9 is a photograph showing controllers at work in the Washington Air Route Traffic Control Center in Leesburg, Virginia. It depicts a typical manual system as now utilized in most centers. The process of manually acquiring, processing, and transmitting flight progress information tends to be cumbersome and time consuming. Consequently, any one controller can handle only a limited number of aircraft at any one time.

While there has been an appreciable increase and innovation in the equipment used for air traffic control, human factors research required to support this growth has not kept pace. There are major areas where these human factors problems are of concern in the air traffic control system as it now exists, as well as those which are likely to emerge as new and more sophisticated equipment is introduced into the system.

Our research program in this area is structured to be relevant regardless of future decisions concerning the design of the equipment and associated software. Although the exact configuration of equipment and facilities which will eventually comprise the system is not well defined at this time, it is clear that for

many years to come, human beings will continue to perform essential functions of processing information and making decisions. This research program is focused on more basic research activities rather than on applied studies, in order to develop a body of basic knowledge in support of developments planned by the FAA for the National Aviation System.

Work has been initiated in measuring operator workload in an information processing task using air controller audio tapes recorded from several commercial airports during heavy traffic density. The work is being performed in close coordination with the Human Factors Branch at the National Aviation Facilities Experimental Center, Atlantic City, New Jersey.

Future research efforts will include the development of measures of operator performance and the assessment of the reliability of these measures.

AIRCRAFT SEAT FOR INCREASED SAFETY AND COMFORT

It was reported last year that two engineering prototypes of an airline seat were being fabricated by Stencel Aero-Engineering Corporation for Ames Research Center. The goal of this program is to design a safe and comfortable passenger aircraft seat that will withstand vertical and horizontal impact accelerations of at least 20 G's utilizing energy-absorbing techniques.

The seats were tested statically and found to be operationally acceptable. Dynamic testing was then initiated. Under vertical loading conditions in excess of 20 G, there was no evidence of structural failure. Under horizontal loading, the seat failed at about one-half the design load. Design modifications are being made to insure a seat structure capable of withstanding 20 G loads in a horizontal direction (over double the failure loads of current transport seats).

SIMULATION TECHNOLOGY

Parallel programs of research are being initiated on the human factors aspects of training simulation and on other aeronautical life sciences problems in which the use of simulators can contribute to solutions.

TRAINING SIMULATORS

Nearly 20 percent of all fatal accidents which have occurred in airline operations in recent years were the result of training accidents, while only three to four percent of the total time flown was in training. The costs of accidents, direct operating expense, and wear and tear in flying the new jumbo jets empty for pilot training and proficiency maintenance purposes are huge in comparison with simulator operating costs.

A goal of the Federal Aviation Administration and of the airlines is to reduce inflight pilot training time to a minimum. This is true of both the initial traning necessary to qualify for new types of aircraft, and of the periodic proficiency checks that each pilot must pass. The FAA (which is responsible for certificating simulators and their use for training purposes) lacks criteria for determining minimum acceptable validity for flight simulators to be utilized in aircrew qualification and recurrent training under realistic operational conditions. The FAA has requested NASA's aid in developing such criteria.

Currently, the jumbo jets are of primary concern. Per-hour operating costs of the aircraft are high and training requirements often dictate that an aircraft be taken out of passenger service. This disrupts the airlines' schedules for aircraft utilization and further adds to costs. In addition, certain procedures required in training for emergencies are inherently dangerous and other emergency conditions, involving damage to the aircraft, cannot be practiced at all.

The NASA Flight Simulator for Advanced Aircraft, located at the Ames Research Center, is capable of simulating aircraft such as the Boeing 747 in normal and emergency flight situations. Figure 10 shows the pilot's view from the cockpit of this simulator. The aircraft cockpit is supported by a mechanism which permits controlled movements in any direction. When the pilot moves the controls, the simulator moves in a manner which gives nearly the same motion sensation as he would experience in the real airplane. Through the cockpit window he sees a scene similar to that which he would see if he were looking out of the window of the airplane. This is presented by means of closed circuit television viewing a terrain model. Simulators of this type and others will be used in research to determine human requirements for simulators.

Simulation is still, however, a subjective and qualitative art and is not yet a complete substitute for actual flight time. This is due to imperfect congruency between the visual, motion, aural, and tactile cues provided by the simulator and

those which obtain in actual aircraft in flight. Intensive research is necessary in order to gain a basic understanding of how man utilizes the interrelated sensory cues of sight, sound, touch, and movement. Such understanding will permit us to generate controlled illusions which will make the limited movements and visual scenes in simulators the subjective equivalent of their counterparts in real aircraft.

RESEARCH SIMULATORS

These serve as tools to support many kinds of research including research to improve training simulators, research on aeromedical problems (such as the measurement of performance degradation due to fatigue), research on display and control problems (for example, the evaluation of new head-up displays), and research on aircraft handling qualities (such as tests of reaction control systems). The overall requirements for research simulation fidelity are usually less exacting than those for training simulation, although there may frequently be a requirement for extreme fidelity in one or a few cues. The basic understanding necessary to advance the technology for training simulators will be applicable also to research simulation.

SUMMARY

The program of the Aeronautical Life Sciences Division is directed toward the development of a life sciences technology to support present and future aeronautical systems. The objectives of this program are twofold: first, to provide information having practical impact on the very real problems of today; second, to provide a base-line life sciences technology upon which designers may draw to insure the proper utilization of man in future aeronautical systems and to predict effectively the influence of these systems on society in general.

Particular attention is being given to the noise problem, both from the operator's point of view and from that of individuals who may live or work near airport areas. The data being developed will be useful in establishing noise tolerance levels for future aeronautical vehicles, for the scheduling of flight operations, and for land planning purposes.

Other topics of special concern include definition of man's role in air traffic control systems, optimization of flight displays and controls, and increasing the effective utilization of aeronautical simulators for operator training and for research purposes.

PREPARED STATEMENT OF ALBERT J. EVANS, ACTING DIRECTOR, AERONAUTICAL PROPULSION, OFFICE OF ADVANCED RESEARCH AND TECHNOLOGY, NATIONAL AERONAUTICS AND SPACE ADMIN

ISTRATION

INTRODUCTION

The primary goal of the Aeronautical Propulsion Research and Technology program is to provide advance technology through analytical and experimental investigations of engine components and engine systems. Figure 1, (RL 71– 3410) Aeronautical Propulsion, is an overview of the Aeronautical Propulsion program which includes research related to quiet engines for subsonic transports, improved engines for supersonic aircraft, powered lift for V/STOL aircraft, turbine engines for small aircraft, and propulsion technology for hypersonic aircraft. These programs are aimed at reducing noise and pollution, improving engine performance, operational capability, safety and reliability, and economic viability. During FY 1972 a great deal of attention will be given to the environmental problems of aircraft noise and pollution. The aircraft noise efforts will include both small scale and full scale research. Particular attention will be given to the problems of aircraft noise for Short Take-Off and Landing Vehicles such as the internally and externally blown wing flap aircraft concepts which are described under the Aerodynamics and Vehicle Systems Program and the STOL Technology Program respectively. In addition to the subsonic aircraft noise research associated with the NASA experimental Quiet Engine program, an extensive research effort will be undertaken to develop an understanding of the sources of noise emanating from high-velocity jets typical of supersonic aircraft propulsion systems and to explore and evaluate methods of noise suppression. Research on pollution is aimed at reducing the amount of smoke and oxides of nitrogen in the jet exhaust.

One of the major NASA noise reduction efforts is the Quiet Engine program, which has been discussed in previous testimony, and is shown schematically in Figure 2, (RL-3412) Experimental Quiet Engine. The program was initiated

59-311 0-71-No. 2, pt. 4-10

to develop and establish the technology required for the design and development of a turbofan engine with significantly reduced noise through basic changes in engine design. Although the Quiet Engine is not being developed for a commercial application, the low-noise technology generated in the program will be made available to industry as quickly as possible, through direct contacts, NASA Advisory Committees, and the Interagency Aircraft Noise Abatement Program which was established as a means of coordinating all aircraft noise activities in the United States.

Some of the important design features of the Quiet Engine program, shown in Figure 2, include: low noise fan rotor/stator configurations optimized in terms of an tip speed, fan pressure ratio, fan blade loading, aspect ratio, blade/vane spacing, blade/vane numbers, etc.; the judicious application of acoustically treated panels to reduce fan and turbine machinery noise; the selection of fan bypass ratio to insure that jet noise from the fan and turbine exhaust jets is as low or lower than fan and turbine machine noise.

By way of a progress report, the program is on schedule and the first fullscale quiet fan and acoustic model fan have been built and aeroacoustic tests are underway. It is expected that the fan test portion of the program will be completed by mid 1971 at which time the first engine will be under test. Engine noise results will be available in early 1972 with delivery of the Quiet Engine to NASA scheduled for the end of 1972.

The Quiet Engine program grew out of NASA's continuing efforts in subsonic aircraft noise research. On one hand, the high bypass ratio of the Quiet Engine reduces the noise of the jet exhaust but transfers the major source of noise to the fan. Fortunately, fan noise can be reduced through the design innovations noted previously. However, on the other hand, the noise associated with the Supersonic Transport is a different problem because of the jet noise associated with the afterburning turbojet being used for the SST. The NASA has had a continuous research effort over the past few years in the area of exhaust nozzles for supersonic aircraft. The focus of the nozzle research was an improved performance over a wide range of flight operating conditions. This work has been mentioned in previous testimony. One of the more promising nozzles in terms of performance is the plug nozzle, a schematic of which is shown in the upper right of Figure 3, (RL 71-3407) Jet Exhaust Nozzle Research-Jet Noise Alleviation. NASA has recently undertaken a cooperative effort with DOT and Boeing to provide assistance in examining some promising noise suppressors. The exhaust nozzle being considered for the SST is approximated in the schematic