Unique flight display concept simplifies the instrument scan

 - October 12, 2007, 7:20 AM

Researchers at the University of West Florida’s Institute for Human and Machine Cognition in Pensacola are developing a symbol-based, flight-deck display that is capable of providing an instantaneous presentation of an aircraft’s flight situation to the pilot. Named Oz, the surprisingly intuitive concept is seen as applicable to all fixed- and rotary-wing aircraft, large and small, civil and military.

The Institute’s research team, headed by David Still, a former U.S. Navy commander with two doctorates in vision science–and also a private pilot currently building a Rutan Long-Eze–developed the Oz concept with $1.2 million in grants from NASA and the Navy’s Aerospace Medical Research Laboratory. (The Oz name came from the need, during early experiments, to have a rear projector operator behind a curtain, reminiscent of the 1939 movie.)

Still claimed that trained pilots typically spend half a second–and often longer–per instrument during a conventional instrument scan. They then must integrate these readings with those from engine instruments and other system indicators–most of which use different units, scales and values–to derive an overall understanding of the current flight environment, which they finally compare to the optimum aerodynamic flight profile. Oz is aimed at eliminating this process.

Instantaneous Situational Awareness
In addition to providing airspeed, attitude, altitude, heading and vertical speed in symbolic form, Oz also graphically portrays the configuration of power settings, lift/drag cues, gear, flaps, trim, navaids, airports and a variety of other data. All information is tailored via software to the specific aircraft’s characteristics, with certain display elements altering smoothly under differing aerodynamic conditions. For example, flap deployment lowers the symbolic stall speed limit, while increased weight and bank angle increase it. Other than heading, which is permanently displayed on an upper horizontal bar, all other numerical target values, such as airspeed, altitude and vertical velocity are initially selected by the pilot to set the graphical display and, once set, can be removed or minimized. From then on, the display provides a complete and instantaneous symbolic picture of the total flight regime.

Oz also replaces the traditional blue/ brown, sky/earth ADI background with a “star field” that moves outward from the center of the screen–somewhat like the opening shots of a “Star Trek” TV serial–to provide powerful attitude and angular heading cues, even when viewed peripherally, to use a word frowned on by vision scientists.

Try It for Yourself
The system’s extensive graphics repertoire includes vertical airspeed bars, which move inward to stall speed and outward to Vne, and also show power available, while the cranked “wings” represent the individual aircraft’s lift/drag ratio curve across its speed range, and kinked at the maximum lift-over-drag point. In more advanced aircraft, the kink is flattened to indicate the best climb rate (Vy) and best climb angle (Vx). Rolling to align an outer wing section with the horizon establishes a standard-rate turn, appropriate to type and airspeed, while setting the lower or upper edge of the center steering circle on the horizon respectively establishes a preset climb or descent rate. And there are many other features, too numerous to describe here.

Still told AIN that military and airline pilots have been impressed by Oz. The system is now ready for flight tests, and Still is shopping around at NASA and elsewhere for an appropriate aircraft. He noted that Oz is compatible with later versions of Microsoft’s Flight Simulator and he can provide interested pilots with data to allow them to test fly the system on their home computers. For more information, contact Still at dstill@ai.uwf.edu.