Graham Warwick/CEDAR RAPIDS
Exploiting the opportunities of the future while avoiding the mistakes of the past is the name of the game in flightdeck design. Excitement generated by the graphics power of the latest displays is tempered with caution engendered by the safety record of today's glass cockpits.
As studies continue to suggest that today's electronic systems are not the advance on yesterday's clockwork cockpits they were once thought to be, particularly when it comes to the pilot's situational awareness (see P36), avionics manufacturers are emphasising human factors in the design of tomorrow's flightdecks.
"The industry is not opportunity-limited. It is also not limited by technology," says Ted Fuhrer, general manager of Rockwell Collins' Business and Regional Systems division. The only potential limit is the human-machine interface, he says.
There is ample evidence at Collins' Cedar Rapids, Iowa, plant that human-factors considerations are driving the design of flightdeck innovations, from a three-dimensional (3D) navigation display soon to be available on Bombardier's Challenger 604, to a "highway-in-the-sky" flight display to be tested later this year on NASA's Boeing 757.
The platform for this work is Collins' Pro Line 21 integrated avionics system, which introduces large liquid-crystal displays (LCDs) with graphics capabilities that dramatically change the way in which information can be presented. Under development for business and regional aircraft, as well as helicopters, Pro Line 21 is also the basis of the company's latest military transport cockpits and is likely to migrate into the air transport market.
As graphical displays move into the cockpit, the design influence of human factors is becoming apparent. Pilot input, for example, led to significant changes in the 3D navigation display developed for the mid-life update of the Challenger 604's Collins Pro Line 4 avionics after it was unveiled.
A 'baby step'
The display graphically presents flight management system (FMS) information that, traditionally, the pilot would interpret and integrate to create a mental picture of the aircraft's flight path. The first offering is fairly simplistic, with a grid representing the ground. Most pilots' first reaction is: "Where's the terrain?" says Collins. It is coming, as is weather and traffic, but only after this first "baby step" is certificated.
Pilot input is evident in the way the display is controlled. In addition to preset plan and side views, a nominal 3D view is available at the press of a button. "100% of pilots prefer the 3D view," says Collins. Once selected, the 3D view can be tilted and rotated, using a joystick. The "most important" feature, autoview, then automatically holds the preferred view as the aircraft changes course. "95-98% of the time pilots prefer 3D with autoview," says Collins.
"About half of our original design assumptions proved correct," the company says. Other pilot-suggested changes are the addition of an aircraft "shadow", to indicate lateral or vertical flightpath deviation, and the use of a "stick aircraft" symbol showing pitch and roll altitude - "a small change with a dramatic impact".
Elsewhere, the flightdeck for the Bell Agusta BA609 is under development. This Pro Line 21 application combines concepts from the fixed- and rotary-wing worlds. Round dials familiar to helicopter pilots are embedded in a full-width artificial horizon, with the horizontal situation indicator on the same large display, providing the close-coupled hand/eye co-ordination required to fly the tiltrotor.
"We learned how to integrate cockpits with the Beech Starship," says Bruce Ray, director, new programmes. "Then [1983] we did human factors with paper, pinning cut-outs to an instrument-panel mockup with magnets to develop the ergonomics of the controls and displays." Today, human-factors design is a science, aided by powerful simulation tools such as Collins' Advanced Flight Deck (AFD).
This is a modular, flexible tool for capturing, defining and refining customer requirements, the company says. It allows designers to evolve a certificated cockpit through a series of iterations using rapid prototyping tools, and with the involvement of users and regulators. Using the AFD, Collins can perform pre-certification work with the regulatory authorities before writing any avionics software.
The AFD features four 340mm (13.3in)-diagonal LCDs, each driven by its own PC, which can be arranged in landscape or portrait format. The cockpit can be reconfigured in a day. Currently, the AFD is being used to evaluate graphical flight planning displays for the business aircraft market.
The large LCD in front of each pilot accommodates a complete primary flight display (PFD) with room left over for additional information windows. Alongside is a multifunction display, which can be divided into four sections to allow flexibility in managing information using a cursor and pull-down windows.
Heads forward
Collins' concept for the future flightdeck allows the crew to be "heads forward" as much as possible by providing an efficient interface with the aircraft systems through the displays. The AFD replaces the traditional head-down FMS control/display unit with a multi-function key panel and cursor control device (CCD).
The CCD shows evidence of significant pilot input. Resting a palm on the device, conveniently located on the centre pedestal, places a trackball under the index figure and stabilises the pilot's hand in turbulence. Trackball friction make it easier to control the cursor as it roams across the two displays in front of the pilot.
The cursor cannot enter some areas, such as the engine displays, while others act as "gravity wells", drawing the cursor to the centre of the active area. Once within a window, the cursor can only move up or down, making it easy to keep in the box. While the CCD can be used to tune the radios, for example, there are other options: pressing a dedicated button to preposition the cursor or turning a direct access knob. Collins is also working on voice control.
While some elements of the AFD are moving to programmes, it will be at least five years before all of the features are in an aircraft. Cursor control is being introduced incrementally, but "no-one yet uses a cursor for flight planning", Collins says.
Human-factors issues associated with the powerful new graphics technology are being tackled first in the business aircraft market. "There are more degrees of freedom in business aviation," Fuhrer says, because there is no dominant manufacturer - no Airbus or Boeing - to provide a rigid specification. The air transport industry will be slower to adopt the new concepts because of its different operating regimen.
"Airlines will not revolutionise flightdecks because of their massive installed base," says Ray, citing their need to standardise training across their fleets. Where airlines are expected to lead is in the use of head-up displays (HUDs). "This tremendous safety device is really changing the industry," he says. Integrating the HUD with a terrain database will allow the display to be used from gate to gate. Certificating a HUD as the primary flight display will also improve despatch reliability, he says.
While development of airliner HUDs is under way using a research flight deck, the next generation of human-machine interface is taking shape in the company's advanced display concepts laboratory. Here Collins is looking five to 10 years ahead, using a fixed-based simulator with sidestick controllers, simulated HUD, 3D audio and voice recognition.
Work on a head-up interface with the FMS has just been completed. This uses cursor and voice to select and enter information. Intelligent automation assists the pilot when planning a flight. Work has begun on human-factors issues associated with controller-pilot datalink communications. Possible improvements to the human-machine interface include using speech synthesis and voice recognitions.
The laboratory's major effort is on NASA's synthetic vision programme, which is developing a perspective-view PFD showing the aircraft's flightpath as a highway in the sky over three-dimensional terrain. The goal is to avoid controlled flight into terrain, loss of control and runway incursions by integrating terrain, obstacles, traffic and even airport representations into an intuitive 3D flight display.
While significant safety benefits are predicted for synthetic vision, its successful development will challenge the avionics industry's hard-won awareness of human factors.
Source: Flight International