Sensors Being Used By The Fms - Honeywell FMZ Series Pilot's Manual

Flight Management System (FMS) for the Agusta AW139/AB139 Helicopter

Sensors Being Used by the FMS

Each FMS tunes the on--side radios. Position sensors in use are
indicated by the letter U displayed before the latitude--longitude position
on the POS SENSORS page.
When the FMS is using VOR and DME data for navigation, a U is
displayed in front of the navaid identifier on the VOR/DME page. In
Figure 6--68, for example, the FMS is using FMN and TBS. When an
FMS is able to tune the VOR and DME and the letter T is displayed, the
FMS is tuning the station and verifying the data from the navaid before
the FMS starts using the station to compute the aircraft position.
The class of a navaid and the aircraft altitude determine when the FMS
can tune and use a navaid for navigation. The class of a navaid is
determined by entering the navaid identification on the DATA BASE
WPT or PILOT WAYPOINT page. The class of the navaid can differ in
the FMS from the published class. This is because the FMS database
class is adjusted to a lower class where stations on the same frequency
interfere with each other at the higher class range limits. Table 6--2
summarizes the range and altitude limits used in selecting navaids for
use.
Range and Altitude Limits for VOR/DME
VOR/DME
Navaid Class
Terminal
Low
High
Unrestricted
Navigation
6-86
Honeywell International Inc. Do not copy without express permission of Honeywell.
Table 6- -2
Aircraft Altitude
≤ 12,000 ft MSL
≤ 18,000 ft MSL
Any
≤ 12,000 ft MSL
> 12,000 ft MSL
Lateral Distance
≤ 40 NM
≤ 70 NM
≤ Lesser of 130 NM or
Line of Sight
≤ Lesser of 130 NM or
Line of Sight
≤ Lesser of 200 NM or
Line of Sight
A28- - 1146- - 181
REV 3 Mar 2009