Antenna Size And Impact On Tilt Management; Rules Of Thumb - Honeywell Primus 880 Pilot's Manual

The antenna size used on the aircraft alters the best tilt settings by
D
about 1_. However, tilt management is the same for either size, as
shown in figure 5- 16.
10- IN. ANTENNA
HAS 10 BEAM

Antenna Size and Impact on Tilt Management

NOTE: A 10- inch antenna is shown for illustration purposes only.
Some of the rules of thumb are described below and shown in figure
D
5- 17.
- A 1_ look down angle looks down 100 ft per mile
- Bottom of beam is 1/2 beam width below tilt setting
- A 12- inch antenna grazes the ground at 100 NM if set to 0_ tilt
at 40,000 ft.
A28- 1146- 102- 00
PRIMUSr 880 Digital Weather Radar System
12- IN. ANTENNA
HAS 7.9 BEAM
Figure 5- 16
TILT

Rules of Thumb

Figure 5- 17
18- IN. ANTENNA
HAS 5.6 BEAM
24- IN. ANTENNA
HAS 4.2 BEAM
BEAM WIDTH
AD- 35702@
Radar Facts
5-15