Piper SENECA III - Page 396

SECTION 9
PIPER
AIRCRAFT
CORPORATION
SUPPLEMENT 21
PA-34-220T,
SENECA
III
Figure
7-!
(cont)
.7°
per
second.
In
ALT
mode,
actuation of the
pitch
modifier will
cause
the
autopilot
to
enter
the
ATT
mode
with
subsequent
operation
as
described
above-
8.
ALT (Altitude)
Mode
Selector
Switch
Selection
of
ALT
mode
will
cause
the
autopilot
to
maintain the
pressure
level
(altitude)
at
the
point
of
engagement.
Because
of
the
pitch
rate
control
provided by
the
autopilot,
altitude
mode
may
be
engaged
from
any
rate
of climb
or
descent,
however,
for
maximum
passenger
comfort,
rate
of
climb
or
descent
should
be
reduced
to
1000
FPM
or
less
prior
to
ALT
mode
engagement.
9.
Test
-
See
Section
4
for
test
procedures.
(a)
SPECIAL
MODES
AND
OPERATIONS
(1)
Glide Slope
(GS) Mode
-
The
GS mode is
fully
automatic.
therefore,
no
GS
engage
switch
is
used.
The
GS
mode
may
be
emered
írom
either
ATT
mode
or
ALT
mode,
from
above the
GS
centerline
or
below
the
centerline.
Activation
of
the
GS
mode
depends
upon
satisfying
two
setsof
conditions:
completion
of
the
ARMING
sequence
and
the
sansfying of
an
equation
relating
to
the
aircraft's
position
relative
to
the
GS
centerline and
the
rate
at
which
the
aircraft
is
approaching
or
departing
from the GS
centerline.
For GS
mode
arming, the
following
conditions
must
exist
simultaneously:
a.
No.
I
NAV
radio
must
be
channeled
to
a
localizer
frequency.
b.
Localizer
deviation
must
be less
than
80W.
c.
Localizer
flag
not
extended
-
valid
LOC
signaL
d
GS Flag
not
extended
-
valid
GS
signal.
e
Svstem
in
APR
mode.
f. Svstem
in
either
ATT
or
ALT
mode.
When the
GS
mode
arming
conditions
are
met,
the
GS
mode
annunciator
will
illuminate
in
conjunction with
the
active pitch
mode.
Loss
of
any
arming
condition
prior
to
GS
capture
will
cause
the
GS
annunciator
to
extinguish
REPORT:
VB-1110
ISSUED: FEBRUARY
10, 1984
I
9-146,
12
of
20