Honeywell Bendix/King KMD 550 Pilot's Manual Addendum page 15

Introduction
See our website at www.bendixking.com for VDL network status and
coverage. Continuous coverage of most of the continental US is possible
at altitudes as low as 5,000 ft. AGL, except for regions of precipitous ter-
rain. As with all VHF communications, the line-of-sight range increases
with altitude. However, there is no appreciable increase in coverage
above 17,500 ft MSL. The following illustration shows how altitude influ-
ences FIS VDL coverage.
The following diagram illustrates how XM Wx data is received in the air-
craft.
The XM Satellite Radio weather system provides continuous coverage
down to ground level over the entire continental United States. A good
view of the southern horizon must be available in order to receive at least
one of the two satellites.
To receive FIS or XM WX products, an aircraft must be equipped with a
compatible VDL receiver (KDR 510) or XM receiver (KDR 610), dedi-
cated VHF antenna or satellite antenna, and appropriate display (KMD
550/850). FIS VDL uses a one-way (ground-to-air) broadcast protocol.
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Revision 6 Feb/2009
KMD 550/850 FIS Addendum