BOMBARDIER BD-100-1A10, Руководство по эксплуатации

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FLIGHT CONTROLS
Sep 13/2004 Flight Crew Operating Manual Volume 2
REV 1 CSP 100-6
10-02-03
SECONDARY FLIGHT CONTROLS (Cont)
HORIZONTAL STABILIZER TRIM
The stabilizer trim can be moved manually by control wheel trim switches or automatically via computer-controlled inputs
from the autopilot, spoilers, or flaps.
Manual trim rates differ, depending on which channel is engaged. When the primary channel is engaged, the trim rate is a
function of airspeed (mach). When the pitch trim secondary channel is engaged, the trim rate is a constant 0.2 degrees per
second.
The primary channel trim rate limit is 0.4 degrees/second at airspeeds up to Mach 0.4, decreasing linearly to 0.1 degrees/
second at Mach 0.8, and 0.1 degrees/second above Mach 0.8. If Mach data is not available, the trim rate limit defaults to
0.2 degrees/second.
CONFIGURATION TRIM
The aircraft has configuration trim, which is automatic trim movement when the flaps are extended or retracted and the
spoilers are extended or retracted. The aircraft has a nose down pitching moment with flap extension and nose up pitching
moment with spoiler extension. When these control surfaces are deflected, the horizontal stabilizer trim moves so as
to reduce the control column forces.
MACH TRIM
The Mach trim function makes allowances for the rearward shift of the aerodynamic center of pressure as the Mach number
increases. Without correction, this shift in the center of pressure decreases longitudinal stability.
The horizontal stabilizer trim control unit automatically adjusts the stabilizer as a function of the Mach number when the
autopilot is not engaged.
The Mach trim system, using Mach information from the air data computers (ADCs), varies the angle of incidence of the
stabilizer by commanding movement of the horizontal stabilizer actuator.
When Mach trim is active, increasing speed from a trimmed condition results in Mach trim inputting slight nose up trim,
increasing the aircraft’s natural speed stability. Likewise, decreasing aircraft speed from a trimmed condition results in
Mach trim inputting slight nose down trim.
The Mach trim system is continuously monitored and any fault detected is displayed on the EICAS display.