Go-Around (Pitch Axis) Mode; Autopilot Pitch Trim - Honeywell SPZ-8000 Maintenance Manual

3. B.
(8) (i) 3 Go-Around (Pitch Axis) Mode
The go-around mode is normally used to transition from an
ILS approach to a climb out condition
when a missed approach
has occurred. The pilot selects go around by pressing the
TOGA button located on either outboard throttle handle.
With go-around selected, all armed and active flight
director modes are cancelled and the autopilot is
disengaged. The GA switch changes state, and a fixed
15-degree GA up bias is routed to the pitch command cue on
the PFD. The 15-degree angle is determined by the aircraft
manufacturer and represents the best climb angle. As the
pilot flys the GA command, pitch attitude information from
the IRS nulls the command and centers the pitch command cue
on the PFD. (A 12-degree GA up bias is
used in the
-906/-907 FGC).
The go-around mode is cancelled by selecting another pitch
mode, engaging TCS, or engaging the autopilot. The
go-around mode is annunciated on the PFD by a green GA.
(j) Autopilot Pitch Trim (See Figure 260, sheet 8)
There are three modes of electric trim operation available:
Manual electric trim
. Mach trim
. Autopilot trim
The trim function will control trim tab motion via digitally
processed closed-loop control laws which utilize motor rate
(tachometer) and motor position (synchro) feedbacks. Each FGC
provides excitation for its own-side trim synchro.
Trim servo travel is limited such that the trim servo does not
drive into the mechanical stops by use of the trim limit
switches in the trim servo bracket. The manual trim wheel can
be used to override the electric trim via a slip clutch (for
emergency use only).
Trim override inputs via the slip clutch
will
cause a change in the relative positions of the trim limit
switches. Therefore, readjustment of the servo linkage may be
required to realign the trim limit switches. When a trim limit
is reached, the trim servo will not continue to drive
in the
current direction, however, the trim servo can be driven in the
opposite direction.
Manual Mode - The manual electric trim mode is active
whenever the electric trim is engaged with the autopilot
disengaged. This mode responds to
trim inputs from the
pilot and copilot yoke mounted trim switches.
The maximum
trim rate shall be t2° tab/see in this mode at low
airspeeds. This speed limit shall decrease with true
airspeed increasing.
22-14-00
Page 298:124
Apr 15/93
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