18th annual conference on manual control.pdf - Acgsc.org

shown by a hexagon if the aircraft was within 500 feet of
ownship. Only the top half of the hexagon showed if the
aircraft was more than 500 feet above and the bottom if more
than 500 feet below. For the no CDTI condition, the display
showed the position of ownship only relative to the navigational
map.
The flight and engine instrument information was
updated every one tenth of a second. The ownship information
on the CDTI including the navigational information, was
updated five times a second. The information on the other
aircraft was only updated every four seconds. No radar
errors were simulated in this study.
Procedure
The subjects were paid for the two days they participated.
Initially, the controller and pilots were briefed on
the experiment and the simulation. The controller's task was
to provide spacing and sequencing for all seven aircraft on
the approach and l_nding. During the first few minutes of a
run, all the aircraft became airborne (randomly placed) at
the navigational fixes south of the San Jose Airport. From
this position the pilots flew their simulators under ATC
control according to the published ILS approach procedures
and landed at San Jose Airport. After an aircraft landed it
was repositioned (with equal probability) at one of the
three outer most positions, 35 miles from the airport. All
the aircraft remained on an instrument flight plan with normal
radio communications carried out with the controller.
The airline pilots flew the simulators manually. The GA
pilots provided autopilot inputs to their aircraft until the
outer marker where an autopilot took control of their aircraft
for the landing.
Ten minutes after the run began, the airport was closed
and the aircraft were put into holding patterns until the
airport reopened five minutes later. Each run lasted thirty
minutes. There was a 25 knot wind above 2000 feet decreasing
linearly to 15 knots on the ground. No turbulence was
simulated.
Training - The first three flights were flown without a
CDTI to familiarize the pilots with the simulators. The
forth and fifth flights were made with the CDTI available
but pilots were not required to use the information for
separation. For the sixth and seventh flights, only two air
carrier aircraft had CDTI.
Experimenta ! Flights - There were six experimental
flights. The first two were made with no CDTI (i.e.
549