Ideal Tilt Angle; Earth's Curvature - Honeywell PRIMUS 660 Pilot's Manual

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PRIMUS 660 Digital Weather Radar System
Tilt management is often misunderstood. It is crucial to safe operation
of airborne weather radar. If radar tilt angles are not properly managed,
weather targets can be missed or underestimated.
The upper levels of convective storms are the most dangerous because
of the probability of violent windshears and large hail. But hail and
windshear are not very reflective because they lack reflective liquid
water.
The figures that follow show the relationship between flight situations
and the correct tilt angle. The first describes a high altitude situation; the
second describes a low altitude situation.
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The ideal tilt angle shows a few ground targets at the edge of the
display as shown in see figure 5–8.
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Earth's curvature can be a factor if altitude is low enough, or if the
selected range is long enough, as shown in figure 5–9.
Radar Facts
5-10

Ideal Tilt Angle

Figure 5–8

Earth's Curvature

Figure 5–9
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