The objective of this paper is to discuss some recent research dealing with testing the pilot useability of new cockpit technologies.

Head-Up Displays have been used worldwide for almost 30 years in over 10,000 aircraft. Helmet-Mounted Displays exist in less than 500 aircraft, most of which are helicopters. This paper examines some of the tradeoffs involved in the selection of each type of display and their related performance comparisons.

The Crewman's Associate will use Virtual Prototyping to evaluate different design concepts. Virtual Prototyping is a process by which advanced computer simulation is used to enable early evaluation of concepts and technologies without actually building those concepts or technologies. The Virtual Prototyping Process will provide the means by which the User is continuously involved in the crew station's design.

Modern aircraft are incredibly complex machines. Although many, if not most, of the functions are automated, the pilot and other cockpit crew members must have access to large amounts ofinformation in a very small period oftime. And this information must be available to them in a format that is easily understood quickly. Today, this information is often provided by Cathode Ray Tube (CRT) screens. These CRTs have many advantages with respect to visualization. That is, color CRTs can have full color, high brightness, large viewing angle, high contrast, and high spatial resolution. The disadvantages lie, to a great extent, in the package. CRTs and their necessary electronics are large, heavy, and fragile. Furthermore, ifbroken accidentally, the resulting implosion can create disaster in the cockpit. Consequently, many display developers of cockpit displays believe that the ideal display should be full color, extremely thin, light weight, energy efficient, exhibit high brightness and high dynamic range, capable of being refreshed in real time without jitter, have high spatial resolution, display a large number of pixels, and be visible over a very wide range of angles (normal to grazing incidence both left-to-right and top-to-bottom). For military aircraft, the display should operate with the same characteristics over a very wide temperature range. This is particularly important in northern climates during the winter, or when the interior ofthe aircraft becomes very cold such as a result of damage to the aircraft body at high altitude (e.g. gunfire, missile attack). In cockpits, the display should also be available in a wide range of sizes include the possible use in head or helmet mounted configurations. There has also been the suggestion that virtual reality glasses might be beneficial in aircraft cockpits. The displays would be available not only for normal instrument readings but also for radar, mapping, computer monitors, and possible cockpit lighting. The ideal cockpit display should exhibit the same full color visual characteristics whether seen in direct sunlight during the day or in a darkened cockpit at night. Some cockpit applications are looking forward to wraparound displays. Todays best information-comprehensive displays for cockpit use are fast-refresh, high brightness cathode ray tubes (CRTs). Unfortunately, a single CRT takes up a lot of room since the depth ofthe CRT is often greater than the screen diagonal. The CRT's fragility impacts cockpit safety. Its brightness is limited by a scanning electron beam which comes from a low current density thermionic cathode. Its lifetime is often a problem because ofbarium evaporation from that same cathode. The CRT cathode needs its own power supply and a separate magnetic scanning circuitry. In fact, most of its energy is wasted on the cathode and scanning circuitry. The energy is not delivered to the user as useful, visible light. Nevertheless, the CRT is still the best display available for cockpit display applications because it creates its own full-color light by cathodoluminescence. Some flat-panel technologies are becoming feasible for cockpit applications, but the CRT is still projected to have a favorable cost-benefit ratio, and superior performance characteristics for some years to come.

The Electronic Library System (ELS), is a proposed data resource for the cockpit which can provide the aircrew with a vast array of technical information on their aircraft and flight plan. This information includes, but is not limited to, approach plates, Jeppeson Charts, and aircraft technical manuals. Most of these data are appropriate for digitization at high resolution (300 spi). Xerox Corporation has developed a flat panel active matrix liquid crystal display, AMLCD, that is an excellent match to the ELS, due to its innovative and aggressive design.

Flat panel display technologies which could replace obsolete airborne cathode ray tubes are still in the development stage and not available as mass produced items. Flight and laboratory assessments were conducted on three technologies: Active Matrix Liquid Crystal Display, AC Gas Plasma Display, and Thin Film Electroluminescent.

This paper describes the cockpit display, its properties and capabilities, and how the technology proven on this display is being incorporated into commercial autostereoscopic devices.

We present a design for a 3D display system that is simultaneously autostereoscopic (no viewer eyewear is required), multiperspective or look-around (horizontal parallax is achieved without head tracking), raster-filled (all pixels have gray scale), and dynamic (live or real-time scenes may be displayed). This system will enable the demonstration of improved pilot performance and situation awareness due to multiperspective (i.e., look-around) viewing capability. The system uses twenty separate small liquid crystal televisions (LCTVs) with corresponding perspective views projected onto a pupil-forming screen consisting of a Fresnel lens and a pair of crossed lenticular arrays. The system will provide design data necessary for the development of a more compact and optically efficient system that uses digital micromirror devices instead of LCTVs.

Honeywell provides both the primary flight instruments (EFIS and EICAS) and the FMS Control and Display Unit (CDU) for the Boeing 777 all-glass flightdeck. These instruments feature high resolution, full color, active matrix, liquid crystal display panels. Both the CDU and the D-Size Display Unit features grayscale, very wide horizontal and vertical viewing angles, high contrast with an achromatic background over viewing angle, a large color gamut, temperature compensation for graylevel stability at all operating temperatures, heaters for cold temperature start-up and 100 fL brightness with a 2000:1 dimming range. The display system architecture, optical performance and key LCD technology features are reviewed here.

Design considerations leading to the Lockheed Sanders Advanced Transport Common Cockpit System architecture are addressed. Emphasis deals with the display characteristics in a human factors and specification sense tied directly to the AMLCD design requirements. Practical aspects of the subsystem design and application will be disclosed in an easy to understand presentation format.

A challenging and exciting program is underway to develop an active matrix liquid crystal display for the National Aeronautics and Space Administration--Rockwell Space Shuttle cockpit upgrade. The Multifunction Electronic Display Subsystem program greatly enhances operational capabilities of the Space Shuttle and improves overall system reliability, replacing multiple electromechanical and obsolete cathode ray tubes with 11 flat-panel displays.

A full-color liquid-crystal display, addressed by a high-speed graphics generator, was used to display a moving map of an airport surface and show the position and orientation of a simulated aircraft (Taxi Map). This Taxi Map was used in NASA flight-simulator experiments which studied the use of electronic maps during aircraft surface operations.

The first generation cockpit used round disks to help the pilot keep the airplane flying right side up. The second generation cockpits used Multifunction Displays and the HUD to interface the pilot with sensors and weapons. What might the third generation cockpit look like? How might it integrate many of these technologies to simplify the pilots life and most of all: what is the payoff? This paper will examine tactical cockpit problems, the technologies needed to solve them and recommend three generations of solutions.

The F-22 is the first exclusively glass cockpit where all instrumentation has been replaced by displays. The F-22 Engineering and Manufacturing Development Program is implementing the display technology proven during the Advanced Tactical Fighter Demonstration and Validation program. This paper will describe how the F-22 goals have been met and some of the tradeoffs that resulted in the current display design.

This paper examines the role that advanced display technology has in the upgrade of the F/A- 18 Hornet to the E/F configuration. Application of Active-Matrix Liquid Crystal Display (AMLCD) technology improves display performance and reliability and enables increased display processing capability. The paper provides a system-level description of two of the new F/A-18E/F displays, the Multipurpose Color Display and the Touch-Sensitive Up-Front Control Display. A brief comparison of performance and capability to the CRT-based display technology that is being displaced is made in conjunction with a discussion of the key performance characteristics of the new display hardware and graphics generation circuitry. An overview of the challenges of incorporating AMLCD technology into an existing tactical fighter crewstation, including optical and thermal performance is provided, followed by a review of the testing that has been performed to validate AMLCD and Touch Sensing technology use in the F/A-18.

Battelle is under contract to design an improved Radar Electro-Optical Display Set for the F- 16A/B and F-16C/D aircraft. This new equipment consists of two units: the Electronics Unit (EU) and the Display Unit (DU). It is designed to be a form fit function replacement for the Indicator Unit and EU in the current F-16A/B aircraft and the Multi-Function Display and Programmable Display Generator in the F-16C/D aircraft. This paper will discuss the improved REO Display Set and specifically address the trade-offs that resulted in the selection of a ruggedized Commercial Off The Shelf LCD rather than a custom LCD for installation in the new DU.

The avionics-grade active-matrix liquid-crystal display (AMLCD) is a highly-specialized display in a custom niche market. In Japan, the commercial AMLCD manufacturers have limited interest in this market for logical, business reasons. The sources of panels are now limited to Toshiba in Japan and OIS Optical Imaging Systems in the U.S. Several avionic electronics manufacturers have established their own source/relationships. The major ones are Honeywell with Hosiden, Sextant Avionique with Thomson LCD, and Litton Systems Canada Limited with their in-house source. The avionics AMLCD panel industry is less than ten years old and will not be mature for another ten years. The panel is perceived to be the ultimate display for avionics, satisfying all aviation display application needs. There is no flat panel option. As the industry matures, the CRT and classical instruments will continue to be replaced. Ultimately, the entire cockpit display ensemble will be AMLCD, as is the case in the new Boeing 777. The entire cockpit display set will be reduced to data bus, computers, and AMLCD panels.

The charter of Image Quest is to develop and produce high quality active matrix LCD products to satisfy the needs of avionic, military and other high performance display applications.

The goal of avionics suppliers is to provide air crews timely and accurate information from various other aircraft systems in order to improve the likelihood of mission success and safety. This goal can be met by accurately defining the desires and requirements of the user. Rockwell uses a number of techniques to accomplish this goal. The final display system may well be defined by a number of these inputs combined through a series of trade-offs. Rockwell is a diversified company that addresses many different display markets. This provides a unique opportunity to compare various techniques for developing and meeting user requirements.

SAE display standards are used as guidelines for certifying commercial airborne electronic displays. The SAE document generation structure and approval process is described. The SAE committees that generate display standards are described. Three SAE documents covering flat panel displays (AS-8034, ARP-4256, and ARP-4260) are discussed with their current status. Head-Up Display documents are also in work.

MIL-L-85762 defines the optical performance requirements of displays in military aircraft cockpits where compatibility with night vision systems is required. A detailed description of the measurement techniques and of the results will be presented. A measurement technique that best simulates actual usage will be recommended.

Electronic display readability in all display operating environments is the final goal of display design. There are a number of operating environment and display performance characteristics that influence readability. The effects of the performance characteristics vary according to the environment. No one display technology or component can give a complete solution to readability requirements without attention to all of these variables. It is strongly recommended that a display designer be included during the early stages of the cockpit or flight deck design process. Otherwise, the display requirements may not reflect the real needs of the user's environment.

A technique and instrumentation were developed which permits a relatively non-skilled operator to make a complete performance check of an electronic display in a very few minutes, providing a go/no-go indication can be configured to indicate the area of failure. The instrument is designed so that a performance profile of each display device or type can be kept on file if desired. This paper reviews test criteria selected for the performance `check' and the novel interrelationship between test stimulus and measuring instrument created for this testing.

Primary characterization of cockpit displays involves taking spectroradiometric measurements. These spectroradiometric measurements require that the equipment to be used be accurately calibrated in all areas. Compliance with the specific requirements involves development of an appropriate sequence of tests and measurements. This paper considers these requirements and presents a detailed outline of the procedures to be followed in the calibration/validation of computer-controllable spectroradiometers, using the EG&G C11 ASR ANVIS measurement system as a target system.

To ensure reliability goals for the 777 display systems are met, Honeywell began a three and one-half year life test of the display backlight systems in July of 1992. To date, sixteen backlight assemblies have accumulated over 12,500 hours of test operation using a luminance profile that is representative of that expected for 777 flight operations. This paper describes design and operating characteristics, life test design, and life test results for the backlight systems of the 777 flight deck displays.

Current AMLCD flat panels for military applications require intense backlighting to permit readability in full sunlit situations. This intense backlighting consumes a great deal of power, which limits their applications, reduces their reliability, and often necessitates cooling. One major factor aggravating this need for intense backlighting is the poor efficiency of the color filters. Not only do these filters have low transmittance, they are not spectrally pure which also results in poor color gamut. Smiths Industries suggests a new version of AMLCDs which does not have these lossy filters, but instead, utilizes a layer of green, red, and blue phosphors embedded within the AMLCD. These phosphors are energized by an ultraviolet backlight. This new technology could decrease the power consumption by a factor of four, while maintaining the same display luminance and contrast.

The Liquid Crystal Display (LCD) is rapidly becoming the technology of choice for high brightness, sunlight readable displays. One of the major drawbacks to this technology is the need for a high luminosity backlight. Fluorescent tubes, one of the most efficient methods of converting electrical energy into light, poorly fit the mechanical and optical requirements of LCD's. Many attempts have been made to address these issues by developing a light source that better meets the optical and mechanical requirements of LCD's. The Wafer LIght is a flat lamp developed specifically to meet the peculiar requirements of avionic displays, and has demonstrated significantly improved efficiency, uniformity, and thermal characteristics.

The demand for increased information content and improved image quality on matrix displays has driven the display manufacturer to provide very high pixel density displays. The new- generation displays have very low luminous transmittance, 2% to 4% typical. The consequence of manufacturing high density, low transmittance displays is a disproportionate burden of performance is placed on the backlight system. Low heat, high luminous efficiency, high dimming ratio backlight systems are the key to success of these growing display technologies. Backlight systems with luminous efficiencies greater than 65 lumens per watt are now available for use with high density displays. These backlight systems lend themselves well to a wide variety of applications including commercial automotive, general aviation aircraft, and advanced military aircraft and ground vehicles where high performance is critical.

We have developed holographic diffusers that provide achromatic forward scattering with low backscatter and absorption, even at large scattering angles. The angular scattering pattern may be highly asymmetric in the azimuth and elevation directions, and may also be skewed away from the incident beam. Volume phase holographic diffusers recorded in dichromated gelatin exhibit particularly low backscatter and absorption, and also exhibit the unique property that the output lobe in some configurations does not move with the input ray angle. These diffuser properties allow the fabrication of efficient, uniform backlights for LCD displays in aircraft cockpits.

The future of cockpit avionics will be shaped by the developments and limitations of display technologies. Large size displays (> 100 square inches) are needed to allow for the fusion of an ever increasing amount of data from advanced sensors and processing. A recent study has shown that fusion of data on large displays will allow for a 28% improvement in fighter kills ratio. The most common electronic display type in use today is the CRT. However, avionics CRTs are currently limited to 6 X 6 inches in size. In addition, the CRT suffers from inherent problems such as large depth, weight, and power requirements as well as poor reliability. The flat panel technology that will be replacing the CRT in cockpit applications is the Active Matrix Liquid Crystal Display (AMLCD). AMLCDs allow for high brightness, full color, low power, low weight, and are very legible in bright sunlight. Several ARPA- sponsored research programs are underway to further improve upon the performance of the AMLCD as well as to lower production costs.

This paper describes the top level architecture and requirements of the resulting Cockpit Display Generator (CDG). The architecture provides the graphical and video processing power needed to drive future high resolution display devices and generate more natural panoramic 3D formats. The CDG will provide multichannel, high performance 2D and 3D graphics, and real-time video manipulation. The architecture is designed for a compact implementation in the PAVE PILLAR environment using high-speed fiber optic networks. The CDG sustains the needs of the Panoramic Cockpit Control and Display System 2000 cockpit; it can be extensible to higher performance levels in PAVE PACE architectures.

A key challenge to tomorrow's real-time 3D rendering engine has been the memory bandwidth barrier that limits how fast an image can be painted onto image memory. Another has been the floating point throughput that limits how much world coordinate data can be mapped to the screen.

This paper outlines the need to develop an advanced graphics presentation system consisting of a high performance, graphics processor coupled with a high pixel count, helmet mounted or head down display device designed for the military avionics environment. The graphics processor required is a multi-channel, modular system capable of generating perspective view, composite graphics from multiple sources to include digital terrain databases, video sensor data, and PHIGS graphics structures. Display devices must be developed which can be manufactured in a range of sizes from 1 in² to 300 in², with pixel densities of up to 2000 pixels per inch, and be readable in sunlight from a wide field of view. These requirements are driven by the desire to update combatants with timely intelligence information as the mission proceeds. This technology is applicable to a wide range of weapon systems to include tactical fighters, battle tanks and highly portable systems to be used by infantry soldiers.

High brightness, color AC-PDPs with sunlight-readable capability have been demonstrated. Area luminances in excess of 200 fL, luminous efficacies of 1 lm/W, pixel resolution of more than 80 full color groups per inch, and gray scale in excess of 6-bits (64 levels) have been achieved within the past year. These attributes combined with wide angles of view, large size scalability, and most importantly, low cost manufacturability make color AC-PDP technology suitable not only for cockpit, but automotive and other high brightness applications as well.

The back-lit Active Matrix-Liquid Crystal Display (AM-LCD) is enjoying increasing popularity as the technology of choice for multi-function displays in next generation air and ground vehicle crew-stations. As the developers of this technology continue to hurdle the present cost and process limitations, it is anticipated that the AM-LCD method will lend itself effectively to all conventional direct view applications. Further, the AM-LCD process does offer a potential growth path toward the panoramic crew stations, possessing large-area, high density (projection mode) and autostereoscopic attributes.

A high-resolution, wide-angle view normally black active matrix liquid crystal display (AMLCD) has been developed for the National Aeronautics and Space Administration- Rockwell Space Shuttle glass cockpit upgrade. With nine 6.71 by 6.71 in. active area AMLCDs on the front panel, all containing vehicle flight information, the displays must exhibit optimal performance over the entire AMLCD viewing envelope [+/- 60 deg horizontal (H) and -10/+45 deg vertical (V)], under dark and high ambient flight deck lighting conditions. Cross-cockpit AMLCDs must support higher off-axis contrast ratios, vertical and horizontal gray-level stability, a consistent and predictable mixture of primary colors, saturated colors over wider angles, and a darker background with respect to typical AMLCD applications. Manufacturing AMLCDs with these characteristics requires special designs for the AMLCD, diffuser, backlight, and liquid crystal display drive scheme, and special manufacturing processes and techniques. This paper addresses Space Shuttle wide- angle normally black AMLCD requirements, optical performance, and manufacturing considerations.

Most important decisions in planning the manufacturing of AMLCDs are interrelated. Plant layout depends upon machine design and process flow, which depend upon process design, material choices and handling techniques, which in turn depend upon available machine technology as well as product design. All of these must be subordinate to specifications of product performance and cost. Since many production processes and issues are interdependent, overlapping, or even conflicting, most planning decisions do not have a simple linear path. We assume a decision sequence for manufacturing planning as follows: product specification, product design, process specification and design, production machine specification and design, facility specification and design, operational design. We will examine options, interrelations and conflicts in several of these areas and discuss the problems and challenges which provide directions for future improvements.

OIS has developed various active matrix liquid crystal displays for the cockpits of several aircraft. Some of these displays have been tested for and are being designed for compliance with the military electromagnetic interference (EMI) requirements spelled out in MIL-STD- 461. Detailed analysis has also been performed on the addressed cell assembly and the flex circuitry to provide guidelines for EMI design. This paper presents the results of tests performed, steps which were taken to become EMI compliant and the results of the analysis.

In the miliary cockpit the Head Up Display (HUD) is being challenged by the Head Mounted Display. This paper considers why the latest fighter aircraft still retain a HUD and how the requirements of the advanced instrument panel have directed the design of the HUD in particular into the use of holographic optics.

An efficient, high intensity, mercury free cathode luminescent lamp/power supply assembly has been designed for use in the backlighting of AMLCD's. It has demonstrated excellent spectral stability over the temperature range of - 55 to 70 degrees C and its dimming range of 1 to 10,000 Ft-L. The CLL has a projected useful life of 10,000 hours. A life test sample currently has 5,000 hours with a decrease of 16% from its' initial level.

New applications of LCDs (liquid crystal displays) particularly in cockpits will require very high performance backlights. We have developed a new type of backlight particularly suitable for these requirements. Device characteristics and predicted performance figures for specific cockpit applications are given.

Direct and reflected sunlight on open canopy crew stations can reduce perceived contrast below acceptable levels. A contrast ratio of 4 to 1 or greater in the ambient illumination is required for good discemability. Achieving this level of performance requires that background reflections off the display screen be suppressed while maintaining adequate light output levels from the display. Over the years, the display device which has enjoyed the most widespread use in cockpits is the cathode ray tube (CRT). However, reflected light from a CRT phosphor is typically 90% and light output levels of over 7000fL coupled with high attenuation optical filters are required for high ambient viewability. The resultant power consumption, short operating life and poor form factor have left much room for improvement.

AMLCD's used in cockpit applications are transmissive devices and therefore require backlighting. The nominal luminance at the front panel is 200 fl for sunlight and 0.1 fl for night vision goggle operation. This corresponds to a backlight luminance of approximately 5000 and 2.5 fl respectively. The industry has been struggling to provide this dimming ratio of 2000:1. Recently dimming ratios of 4000:1 and 8000:1 have been requested to provide better compatibility with night vision goggles. This is analogous to operation from sun light to star light. The problem with conventional lamp systems has been that the lamps stop fluorescing at low levels. This paper presents a summary of the methods developed to control conduction and hence luminance. When the methods were implemented, it was demonstrated that dimming ratios of 50,000:1 are achievable.

Flight instruments have begun to use color active liquid crystal displays (AMLCDs), signaling the beginning of a significant transition from electromechanical and cathode ray tube display designs to AMLCD designs. We have the opportunity with this new technology to establish common products capable of meeting user requirements for sunlight-readable, color and gray scale-capable, high-pixel-count, flat-panel displays for weapon systems. The Wright Laboratory is leading the development of standard and specification documentation for this new generation of display modules based on requirements for U.S. military aircraft. These requirements are similar in many ways to those of both the civil aviation and automotive industries. Accordingly, commonality with these applications is incorporated, where possible, along with the requirements for all military combat applications. Industry and government organizations are involved in this process through workshops and draft review processes. Military procurement specifications for combat system applications may use this information as a source of recommended best practice for this new generation of digital flat panel displays. The draft standard will be revised based upon continuing feedback by early 1995.