Published Report (DOT/FAA/CT-94-36)

Technical Center. Indicated air speeds of 180 knots (kn) were
assigned for turbojets, 150 kn for turboprops, and 120 kn for
twin engine piston aircraft. Preliminary data indicated that
during the simulation, a total of 746 blunders were initiated,
376 for the triple approach configuration and 370 for the
quadruple approach configuration. Approximately 74 percent of
all blundering aircraft did not respond to air traffic control
(ATC) commands.
Preliminary data analyses indicated that the test criterion
violations (TCV's) (aircraft separated by less than or equal to
500 feet) exceeded the test criterion rate of 2 percent set to
evaluate the operation. However, the number of NBO's and NTZ
entries was acceptable based on the criteria set by the TWG.
Qualitative data from the controller questionnaires indicated
that when the ARTS IIIA display was used, it was "very difficultvv
to perform the monitor controller task. The controllers also
disagreed with the statement that Ittriple independent IFR
approaches to runways spaced 5280 and 7600 ft apart can be safely
conducted as simulated.11
After reviewing the preliminary data, controller opinions, and
technical observer comments, it was decided that an additional
high density altitude simulation should be conducted using the
Full Digital ARTS I11 Display System (FDADS) and data specific to
DIA. To make this simulation site specific to DIA, additional
information about air traffic and airport operations was
requested from representatives from the Northwest Mountain Region
and the Air Traffic Division of the FAA.
1.1.1.2 Simulation Usina the FDADS.
A second simulation was conducted to evaluate the performance of
controllers monitoring triple simultaneous approaches to parallel
runways using the FDADS. In this simulation, assigned aircraft
speeds were kept at 170 kn for all turbojet and turboprop
aircraft. Additionally, twin-engine piston aircraft were
assigned a 150 kn IAS. The three-week simulation began on
November 16, 1992, but was terminated on November 18, 1992,
because preliminary data indicated that the operation would not
meet performance goals set by the TWG.
Preliminary data for aircraft separation, NBO's, and NTZ entries
were reviewed daily. At the end of the second day of simulation,
1169 aircraft were handled, 87 blunders were initiated into
flight simulators, and 5 TCV's were reported. Although the data
for NTZ entries and NBO's appeared to be within the goals set by
the TWG, this sample of data (5 TCV's out of 87 blunders = 5.7
percent TCV rate) exceeded the blunder resolution performance
goal set by the TWG. Additionally, TWG members, simulation
participants, and observers from FAA Headquarters and the
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