Helping Pilots See Through the Soup
Langley Concepts Will Help Reduce Terminal Delays
Future subsonic flight decks are likely to have "enhanced
vison" for a "situation-at-a-glance"
advantage during low-visibility operations. Head-up displays
(HUDs) would display essential
information during critical phases of flight on a transparent
screen between the pilots and the
forward cockpit window. In advanced subsonic transports, HUDs are
likely to be accompanied
by additional upgrades of the cockpit like the large-screen,
flat-panel displays illustrated here.
NASA is studying advanced concepts that will allow airline pilots
to fly and land safely in very low-visibility conditions, thereby
increasing the number of flights in poor weather, reducing terminal
delays, and cutting costs for the airline industry and the flying
An extension of the same technology may allow safe and efficient
"windowless" cockpits for pilots of advanced U. S. supersonic
transports after the turn of the century. Eliminating
forward-looking windows and replacing them with "synthetic vision"
could dramatically reduce operating costs. Both applications will
make use of weather-penetrating sensors and innovative,
pilot-friendly cockpit displays.
Program is government-industry effort
Candidate sensor/display concepts and requirements are being
developed at NASA Langley Research Center, Hampton, Va. and NASA
Ames Research Center, Mountain View, with the FAA and industry.
Industry will be largely responsible for developing the technology
to implement these concepts in response to airline needs.
Sensor concepts being examined now will allow pilots to see
objects - including the runway and other aircraft - through fog,
heavy rain, and snow, which are usually to blame for flight
cancellations and airport closings. Sensor concepts include a
forward-looking infrared system that would provide heat-related
images from objects ahead of the airliner. This concept would be
used primarily at night and under light fog and haze conditions.
Another sensor concept would produce images using a passive camera
or active radar operating at millimeter wave frequencies -
frequencies which have demonstrated potential for penetrating heavy
fog. Each concept has its advantages and disadvantages. The
solution may be to electronically fuse the image data from several
sensors for a piercing, yet realistic, view of the scene ahead.
Computer-painted scenes may help pilots fly "blind."
This synthetic vision display presents a high-fidelity, color,
3-D pictorial image overlaid with helpful symbols.
Innovative, pilot-friendly cockpit displays
Future display concepts under test at Langley include
integrated, pictorial displays with "real-world" formats - possibly
with stereo vision-presented on large panoramic screens. For
example, one "real-world" display format being studied at Langley
presents guidance information in the form of a
"pathway-in-the-sky". These features contribute to giving a pilot a
"situation at a glance" advantage.
'Enhanced vision' for subsonic commmercial
For the nearer-term application, called "enhanced vision,"
airline pilots will likely have a "head-up" display (HUD), through
which they will view a sensor-derived scene complete with
superimposed aiding symbology . Together, they will give the pilot
precise landing guidance.
The HUD would supplement the head-down primary displays by
providing the pilot with essential information during critical
phases of flight (particularly, landing and takeoff) on a
transparent screen between himself and the forward cockpit window.
This concept would allow the pilot to see through the window at the
same time. Enhanced vision technology could be available for
retrofit on today's airliners before the end of the decade.
In the application of enhanced vision to new subsonic
transports, the HUD is likely to be accompanied by additional
upgrades of the cockpit. Here, large-screen flat-panel display
technology may enable the new pictorial display concepts to be
employed for head-down displays as well. Flatpanel displays promise
to extend the advantages of existing computer-driven cathode ray
tube (CRT) displays by being lighter, more reliable, and providing
the larger screen sizes required by pictorial display concepts -
without incurring the bulk, weight, and depth-behind-panel
penalties that the use of large CRTs would entail.
Synthetic vision would allow windowless
For the farther-term supersonic transport application, pilots
will likely have full-time "synthetic vision" with no forward
windows at all. And, of course, without forward windows, they will
not have head-up displays. As presently envisioned, computers will
paint a synthetic picture, derived from sensors and stored
geographic data bases, on two head-down or "virtual window"
panoramic displays that will serve both pilot and copilot - or each
pilot might wear a lightweight helmet-mounted display that senses
which direction the pilot is looking to provide a wider
In a synthetic vision experiment at Langley, 14 commercial
airline pilots "flew" a one-person cockpit simulator to help
evaluate the benefits of these new concepts and technologies. On
the simulator's 15-inch high by 40-inch (38 by 102 cm) wide screen
was displayed a color, pictorial scene representing a 70 degree
field of view. Overlaid were "pathway-in-the-sky" symbols to help
guide the pilots over curved, descending flight paths for precise
approach and landings. The pilots' demanding flight task was
representative of future requirements for precision approach to
closely-spaced parallel runways, while remaining aware of other
traffic in the terminal area. The pilots judged the pictorial
display concepts easier to fly than the flight system they are
flying today and that the pictorial concepts provided better
A NASA research techinician operates a rapidly reconfigurable
flight display Simulator.
Known as the Visual Imaging Simualator Transport Aircraft Systems
the simulator allows researchers to compare conventional flight
with wide field-of-view, integrated, pictorial display
Synthetic vision and windowless cockpits are at early stages of
evaluation by NASA and industry for a possible next generation
High-Speed Civil Transport (HSCT). Synthetic vision capability
would save weight by avoiding the droop nose of the British-French
Concorde and by reducing fuel reserves. The Concorde's nose swings
down at takeoff and landing for pilot visibility. Fuel reserves
could be significantly less in an aircraft with all-weather,
all-site takeoff and landing capability.
Technology being developed by NASA and others to help pilots
through fog and heavy rain may be extended to do away with
cockpit windows altogether on the country's first supersonic
Studies indicate that a fixed-nose design would trim up to 1,500
- 2,500 pounds (675 - 1, 125 kg) from the structural weight of a
supersonic transport and eliminate several times that weight in
additional fuel required for the droop-nose mechanism. Further, a
fixed-nose design (with synthetic vision) would allow for a longer
nose with reduced drag. In total, an all-weather, all-site
supersonic transport with fixed nose and synthetic vision could
trim up 40,000 pounds (18,000 kg) of reserve fuel, resulting in
significant savings in operating costs.