Piper SENECA III - Page 289

PIPER
AIRCRAFT
CORPORATION
SECTION 9
PA-34-220T,
SENECA IH
SUPPLEMENT
5
(4)
Altitude Hold Mode
(ALT):
When
the
AP
is
engaged
and the ALT
switch
on
the Mode
Controller
is pressed,
the
airplane
will
maintain
the
pressure
altitude existing
at
the time the
switch
is
depressed. For
smooth
operation,
engage
the ALT
at
no
greater
than 500 feet
per
minute climb
or
descent. The
ALT
will automatically
disengage
when
the
glide
slope
couples. ALT bold
may
be turned
off
at
any
time
by depressing the
ALT
switch.
ALT
engagement
is
displayed
on
the
annunciator
panel.
NOTE
The
"Vertical Trim"
switch,
located
on
the
Mode
Controller,
may
be
used
to
change
or
trim
the
command
altitude
up
or
down
at
500
to
700
FPM
without
disengaging the mode.
The
new
pressure
altitude
that
exists
when
the
switch
is
released
will
then
be
held.
(5)
Heading Mode
(HDG):
Set
the
heading
bug
to
the
desired heading
on
the
PNL
engage
the AP,
depress
the
HDG
switch
on
the Mode
Controller
and
HDG
will
be
displayed
on
the
annunciator
panel.
The AP
will
command
a
turn
to
the
heading selected. The pilot
may
then
choose
any
new
heading by merely
setting
the bug
on
a
new
heading. The AP
will
automatically
command
a
turn
in
the
direction
of
the
new
setting.
To
disengage
the
HDG
mode,
depress
the
HDG switch
on
the Mode Controller and
observe
the
HDG light
go
out
on
the annunciator. The HDG
mode
will
automatically
disengage
when
APPR
or
NAV CPLD is
achieved,
(6)
Navigation Mode
(NAV):
The
Navigation mode
may
be
selected by tuning
the
NAV
receiver
to
the
desired
frequency,
setting
the CDI
to
the
desired
radial
and
depressing the NAV
switch
on
the
Mode Controller.
The
annunciator will
indicate
NAV
ARM
until
capture
of
the
selected
course,
unless
the
NAV
switch
is
engaged
with
wings
level
and
a
centered
needle
on
the
CDI. Then the
mode
will
go
directly
to
NAV CPLD
as
displayed
on
the annunciator
panel.
The
system
can
intercept
at
any
angle
up
to
90°
and will
always
turn
toward
the
course
pointer.
If
a
condition
requiring
a
ISSUED:
APRIL
21,
1981
REPORT:
VB-1110
II
of
16, 9-43