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MAINTENANCE MANUAL
(i)
Roll Channel Signal Processing
1) Roll channel signal processing generates the cosine of the roll attitude command which is used for the versine computation.
(j)
Pitch Flight Director Signal Processing
1) Pitch flight director signal processing generates the pitch F/D bar command from the pitch path command input.
(8) Vertical Speed Control Logic
(a) Vertical Speed Mode Inactive
1) The logic zero condition for vertical speed engage shown in Fig. 10 is generated with the following 3 conditions: a) F/D ON with the CMD switch selected to CMD. This
generates a F/D DISENG momentary high pulse. b) Altitude hold mode selected. This causes the input to vertical speed engage gate to go high.
c) Vertical speed entry conditions not satisfied. This causes the input to vertical speed engage gate to go low.
2) Any of the above conditions generate a vertical speed engage logic zero which allows synchronization of the existing V/S command. The vertical speed engage valid computation is normally set to one as a configuration management interlock.
3) The logic zero condition for vertical path control is generated when: a) Vertical speed engage is zero (disengaged) b) Glideslope engage or altitude hold engage and a
one-shot pulse for a vertical position mode change is
generated.
4) Both of the above conditions generate a vertical path control logic zero. This opens the path for pitch rate compensation which is composed of wind acceleration and AOA rate filters.
(b) Vertical speed Mode Engaged
1) Vertical speed engage logic one is generated to provide vertical speed command control with the following conditions: a) The F/D switch ON and a REQUEST and CMD VALID pulse
gone low provide a zero state for F/D Disengage.
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MAINTENANCE MANUAL
b) Altitude hold is not engaged. c) Manual or automatic V/S mode entry conditions are satisfied for V/S mode transition generates a high. d) V/S engage valid equals one.
2) When vertical speed engage equals one, the pitch rate compensation path to the pitch attitude integrator is closed. This logic one condition for vertical speed control is generated when: a) Vertical speed engage is equal to one or b) Glideslope engage, flare engage, or altitude hold
engage is high and the one-shot input to G11 is low due to no mode changes.
(9) Vertical Speed Control Signal Flow and Monitoring
(a) Gain Schedule Signal Processing
1) The cosine of the PHI CMD gain schedule shown in Fig. 11 is developed from a cosine computation of the roll attitude command.
2) The angle of attack (AOA) and true airspeed (TAS) gain schedule computation is computed from impact pressure (IAS) and TAS which have been modified by flap position.
3) The TAS inverse gain schedule computation is computed from TAS modified by flap position. 4) The versine compensation gain schedule computation is computed from impact pressure and flap position.
(10) Vertical Speed Command Processing
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