Piper SENECA III - Page 397

PIPER
AIRCRAFT
CORPORATION
SECTION 9
PA-34-220T,
SENECA
IN
SUPPLEMENT
21
GS
mode
activation
(GS
capture)
is indicated
by
the active
pitch
mode
annunCL3(Of
CXtinguishmg,
leaving
only the
GS
annunciator
lighted.
Since
GS
made
activation
results
from
a
combination
of
position
and
rate
information,
GS
capture
will
probabÌy
occur
before the US
needic
centers
in
such
a manner
that the
transition
on
to
the
GS
centerline
will
be
anticipated
and
therefore,
very
smooth.
After GS
capture.
loss
of
valid
GS
signal
will
cause
the
GS
annunciator
to
flash. Also selection of
HDG.
NAV
or
REY
mode
will
cause
GS
to
flash. indicanng
an
inconsistent
GS
tracking
condition.
APR
mode
must
be
selected
while tracking
glide
slope.
The
GS
mode
may
be
deactivated
by
selection of
any
other
pitch
mode
(ATT,
ALT).
however,
automatic
reactivation
is
possible
from
any
pitch
mode
if
APR
mode
is
selected.
NOTE
If
valid
glide
slope
data is lost
after
coupling,
the
autopilot
will
NOT
automatically
decouple.
however
the
GS light
will
flash. The
pilot
must
monitor
raw course
guidance data during
the
approach
to
assure
signal qualty.
Since
GS
arm
and
capture
are
automatic
when
the arming
and
capture
sequence
is
met.the
GS
must
be
locked
out
for
holding
operations
on
the
localizer
at
the
L.O.M.
When localizer
holding
is desired. localizer
tracking
must
be performed in
NAV mode
which will offer
the
same
tracking
dynamics
as
APR
mode
but
will
inhibit GS
arm
and
capture.
When
APR
clearance
is
received,
select
APR mode for
completion of
the
approach.
(2)
Selected
Angle Intercepts
-
If
an
H.S.l
type
heading
system
is
installed,
selected
angle intercepts
may
be
made
during
VOR
or
localizer
intercept
situations
by
selecting
HDG
and
NAV,
HDG
and
APR,
or
HDG -and REV,
simultaneousiv,
as
appropriate.
During
a
selected angle
intercept
operation, the
autopilot
will
follow
the
heading
bug
until
reaching
the
computed
On
Course
Turn
Point
at
which
time
capture
is
indicated by
extinguishing of the
HDG
mode
annunciator.
Selected
angle
intercepts
of
over
60°
are
not
recommended.
ISSUED:
FEBRUARY 10,
1984
REPORT: VB-1110
13
of
20, 9-147