Altitude Preselect Operation; Vertical Speed Select Operation; Altitude Alerting - Honeywell KFC 150 Pilot's Manual

Altitude Preselect Operation
To select a new altitude, the KAS 2978
must be displaying feet
(FT). If
it is display-
ing feet per minute (FT/MIN), push the inner
concentric knob to the 'in' position.
Rotating the outer concentric knob will
select altitude in 1000 ft. increments up to a
maximum of 35,000 feet. The inner concen-
tric knob controls altitude in 100 ft. incre-
ments.
entered, push the ARM button to arm the
altitude capture mode. Use pitch attitude
hold or select a vertical speed to guide the
aircraft to the new altitude.
As the aircraft nears the selected alti-
tude, a pitch round out is computed by the
KAS 2978 based on the aircraft's vertical
speed. When the KAS 2978 determines the
round out should begin, the display will
change from arm (ARM) to capture (CAPT)
and Vertical Speed mode will be disen-
gaged if it was in use. At the selected alti-
tude, Altitude Hold is engaged and CAPT
mode is disengaged.
Once the correct altitude has been
Altitude Alerting
Regardless of whether the flight control
system is engaged, the KAS 2978 provides
altitude alerting to alert arrival at and devia-
tion from the selected altitude.
from the selected altitude, the KAS 2978 will
annunciate ALERT and a 2 second aural
tone will sound. The ALERT will stay
When the aircraft reaches 1,000 feet
on until 300 feet* from selected altitude.
When the aircraft reaches the selected alti-
tude, a 2 second ALERT annunciation and
aural tone alerts the pilot to the aircraft's
altitude.
Until a new altitude is selected, the
system will provide alerting any time the air-
craft's altitude varies more than 300 feet*
from the selected altitude.
at time of installation to be either selected
altitude i500 or i 3 0 0 feet. Particular STC's
may require the use of one of these set-
tings. Consult your aircraft Flight Manual
Supplement for details.
*The inner alerting altitude can be set
- .
Vertical Speed Select Operation
Vertical speed may be engaged in
either of two ways: by preselecting a verti-
cal speed on the KAS 2978 or by engaging
vertical speed at its present value and then
modifying a rate of climb or descent using
the vertical trim rocker switch on the KC
191/192, the CWS button or rotating the
select knob on the KAS 2978 with the inner
knob pulled
to
the out position.
NOTE: The pointer of a mechanical Vertical
Speed Indicator has a w i c a l accuracy of
i 5 to i 1 5 % depending on rate and altitude.
Therefore, the aircraft may actually be hold-
ing the selected vertical speed even if the
mechanical VSI disagrees. Timing altitude
changes (e.9. 500 ft/min for 3 minutes
should yield a 1,500 ft change in altitude) is
the most accurate method of determining
which is correct.
indication inherent in their design
(Instantaneous, or lVSl indicators, reduce
this lag considerably). Comparisons made
Also VSl's have a substantial lag in
prior to the stabilization of vertical speed
will not be valid.
90
.