2003 IMTA Proceedings - International Military Testing Association

Fig. 4b: Heading performance of the volunteer (as RMS error in degrees) for light turbulence
over the complete run, alternating between OZ and the CD.
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Figure 4 shows that the flight performance obtained with the two displays is different.
Among the most obvious differences is that flight performance with OZ has smaller RMS values
than that obtained with CD. This was true for altitude as well as heading control. With CD, this
participant frequently lost control of heading (over 135° error) and/or altitude (over 200 feet
error); but never lost control of either with OZ. Furthermore, there was a difference in how
performance changed as the run progressed. Performance with both displays improved at about
the 40 minute mark. OZ’s superior flight performance improved slightly. CD’s relatively poor
starting flight performance improved by over a factor of 8 for altitude and a factor of 4 for
heading by the end of the run nonetheless, performance was still far worse with CD than with
OZ.
To evaluate the effect of display, turbulence, and experience, data from each combination
of conditions were divided chronologically into a first and last half for each run, and each half
averaged to produce a mean RMS error. Thus, the data of Figure 4 produced four mean RMS
altitude values and four mean RMS heading values, two for OZ and two for CD. Panel (a) of
Figure 5 shows mean RMS altitude error; panel (b) shows mean RMS heading error. The
horizontal axis of each panel is divided into the first half and the second half of the run.
45 th Annual Conference of the International Military Testing Association
Pensacola, Florida, 3-6 November 2003
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