Honeywell PRIMUS 1000 Pilot's Manual page 48

R
PRIMUS 1000 Integrated Avionics System
By using the SET knob and selecting the correct button, the crew can
enter either the start–of–descent or start–of–climb distance to (TO) or
from (FR) a station, the station elevation (ST EL), and the target altitude
(ALT). From these inputs, vertical flight path angle (VANG) and vertical
speed (VS) are calculated and displayed. The operation of the SNGP
VNAV differs depending on the NAV source.
D
VOR NAV Source – On power–up, the data field under the TO label
contains dashes. When the TO button is pushed the first time, a
white box is displayed around the dashes, as shown in Figure 3–8,
signifying that the TO distance is in the set mode. The TO button
toggles between TO and FR. Use the SET knob to enter the distance
to the VOR. TO and FR values cannot be entered at the same time.
The most recently set value remains while the earlier set value is
removed and replaced with dashes. TO and FR distances range
from 0 to 99.9 NM, with a resolution of 0.1 NM.
The station elevation (ST EL) must be entered. When the ST EL
button is pushed, a white box appears around the ST EL data field,
and station elevation can be entered using the SET knob. The
setting can range from 0 to 10,000 feet, in increments of 100 feet.
A descend–to or climb–to target altitude must also be entered, using
the ALT knob.
Once data has been set, and if the VNAV problem is valid, a
calculated VANG and VS solution is displayed. The maximum valid
VANG is 6.0° or less, with a resolution of 0.1°. The vertical flight path
angle can be refined by pushing the VANG button and setting a new
angle with the SET knob.
The VS button performs no function. The label and value show only
predicted vertical speed, giving an estimate of the climb or descent
rate for the existing airspeed and selected vertical flight path angle.
On power–up, or if the VNAV problem is invalid, dashes are
displayed in the VANG and VS data fields.
The VNAV setup data is routed to the flight director when the pilot
pushes the VNAV button on the fight director mode selector. Once
this occurs, the VNAV problem is frozen and any attempt to change
the VANG, ST EL, and/or TO/FR data fields is ignored. However, if
the selected altitude is changed, the VNAV mode can be dropped.
Electronic Flight Instrument System (EFIS)
3-10
A28–1146–134
REV 1 Jan/03