Piper SENECA III - Page 273

PIPER
AIRCRAFT
CORPORATION
SECTION
9
PA-34-220T,
SENECA
III
SUPPLEMENT
4
(3)
Flight
Director Mode:
The
FD
must
be
engaged
before
the
AP
can
be
engaged.
The
FD
mode alone
indicates
PAH and wings
level.
The pilot
may
choose
to
fly
the
FDI
commands manually, without
the AP
engaged,
by
depressing
the
FD
switch
on
the
Mode
Controller
or
selecting
any
of
the
other
modes
he
wishes
to
follow.
When
the
AP
is
engaged,
the
airplane will
automatically
follow
the
FDl
commands.
The
FD
may
be
disengaged
by depressing
the
FD
switch
on
the
M
ode
Controller,
If
the
A
P
is
engaged the
FD
cannot
be
turned
off without
first
disconnecting
the
A
P
or
by
pressing
the
AP
DISC/TRIM INTERRUPT
switch
on
the
pilot's
control wheel.
FD mode
engagement
is
displayed
on
the
annunciator.
NOTE
The
"Vertical
Trim"
switch,
located
on
the
Mode Controller,
may
be
used
to
trim
the
command
pitch
attitude
at
a
rate
of
one
degree
per
second
(the pitch
attitude
degrees
legend
on
the
airplane
attitude
indicator
will
not
indicate
accurate
FDI pitch
steering
bar
pitch
attitude
in
degrees).
(4)
Altitude Hold
Mode (ALT):
When the
ALT
switch
on
the
Mode Controller is
pressed,
the
FDI
will
provide
commands
for
maintaining
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/descent.
The
ALT
will automatically
disengage
when
glide slope
couples
or
the
go-around
switch is
depressed.
ALT hold
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.
ISSUED:
APRIL
21,
1981
REPORT:
VB-Ill0
(
11 of
16,
9-29
i