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

TABLE 8. TCV DATA, TWA621/AAL204
Blundering Aircraft Evading Aircraft
11
II
11
Runway 17L 17R
I
I
I
Call Sign
TWA621
AAL204
Groundspeed at
Blunder Start (kn)
Altitude at
Blunder Start (ft)
CPA (ft)
200 184
8307 8457
301 at 7.9 nmi from runway threshold
The pilot of the evading aircraft was flying by hand (i-e., raw
data) at the time of the blunder. The site coordinator log
indicated a llnormalll breakout maneuver with a maximum observed
bank angle of 30 degrees. The site coordinator noted that the
initial ATC instruction was a turn to 270 and a climb to 11,000.
A second heading of 320 was later given.
Table 9 is a record of the dialogue between the controllers and
pilots during the conflict. Transmission times were extracted
from the video tape of the run and reflect real-time minutes and
seconds of the simulation clock.
One technical observer attributed the TCV to slow pilot and
aircraft response. The observer wrote, VWA 621, NORDO. 17R
pilot slow to turn."
The controller for the 17R runway (i.e., evading aircraft runway)
wrote that the blunder was self-identified. He noted that he saw
the blundering aircraft right of the 17L localizer, but not in
the NTZ. The controller stated that he immediately turned and
climbed AAL204, before TWA621 entered the NTZ. The controller
identified pilot action and a slow aircraft turn as the causal
factors in the conflict. The controller also wrote that, Vwo
factors contributed to the conflict: 1) speed overtake -
blundering aircraft was flying 20 kn faster than the evading
aircraft, and 2) the evading aircraft was slow in turning and
climbing.11 It was recommended that to prevent a recurrence of
this type of conflict, the evading aircraft should use a faster
turn rate.
The controller for the blundering aircraft runway (i.e., 17L)
noted that he self-identified the blunder when TWA621 deviated
from course. The controller attempted to turn TWA621, but he did
not get a response. The controller also identified pilot action
29