Autopilot System Flashcards
What 3 systems interact with the autopilot system to fly the aircraft?
Flight control system
Attitude and air data system
Engine control system
The autopilot controls what systems under autonomous flight? (6 systems)
Navigation system Transponder control system Airborne datalink control system An/Das-1 sensor control system Video data system Lynx SAR
What is SAS and when is it turned on?
automatically upon boot up of the PSO workstation or when/as commanded.
What is cruise mode?
cruise mode reduces control sensitivity. roll pitch and yaw gains are scaled with airspeed
In cruise mode, scaling limits roll to +/-_____ up to +/-_____ depending on airspeed.
10 up to 40
Cruise mode is on when _________.
any of the following conditions exist: any hold mode engaged, airspeed is over 110kias, or stall protect is enabled
Cruise mode is automatically turned on as the aircraft accelerates to greater than ___KIAS and will tun off as the aircraft decelerates below ___KIAS.
110, 100
What autopilot override function is automatically activated when cruise mode is on?
roll limit override
What is meant by ‘launch and recovery mode’?
heading, airspeed, altitude holds and stall protect off
WARNING when in cruise mode off, the aircraft may go lost link after the _sec arming time. Once lost link, it defaults to cruise mode on which forces the aiming time to __sec. To prevent this avoid flying cruise mode off when in Ku.
2, 10
What is the minimum allowable airspeed command?
a speed that would require a 1g CL of 1.25 for level flight
In altitude preference mode, the maximum allowable commanded airspeed is ___KIAS or ___KTAS, whichever is ______.
180KIAS, 240KTAS, slower
In airspeed preference mode, the maximum allowable commanded airspeed is ___KIAS or ___KTAS, whichever is ______.
190KIAS, 240KTAS, slower
With altitude hold on, airspeed is limited by which safety mode?
Dive priority mode
What does the airspeed limit override feature do?
prevents the pilot from commanding an airspeed that would result in a CL lower than 1.25 (1.05 when the auto flap schedule is not active or the gear is down). automatically overrides the commanded airspeed and sets minimum airspeed
When is airspeed limit override automatically activated?
when airspeed hold is on
In altitude preference mode, the aircraft attempts to maintain airspeed for the commanded altitude by adjusting ______.
the THROTTLE SETTING calculated by the closed loop power function
In airspeed preference mode, the aircraft attempts to maintain airspeed for the commanded altitude by adjusting _____.
PITCH, maintaining the commanded throttle setting.
Commands for both climbs and descents default to ____fpm
1000
Climb rates are selectable between ___ and ____fpm
100-3000fpm
Descent rates are selectable between -___ and ____fpm.
-100-2000fpm
For aircraft in speed preference mode CL___ or greater, airspeed hold takes precedence over altitude hold. The aircraft will remain in speed preference until CL is ___or less.
1.0, 0.9 0.8,0.7 (903.8)
If the aircraft is unable to maintain the set speed and altitude, it will achieve the fastest possible airspeed while maintaining commanded altitude. The aircraft will remain in altitude preference mode until CL is greater than ___. Once the CL decreases to ___, the aircraft will again be in altitude preference mode.
1.0, 0.9
What is dive priority mode?
prevents the aircraft from inadvertently exceeding Vne during a dive by setting power to idle and controlling airspeed with pitch.
When does dive priority mode automatically engage?
during a descent in altitude preference mode when indicated airspeed comes within 5 KIAS of Vne (190IAS or 240TAS)
What is the point in speed priority override?
In altitude pref mode, the aircraft will maintain altitude via pitch command. As altitude takes preference over airspeed, its necessary to have additional protection to prevent a stall.
If the indicated airspeed slow to a corresponding CL of ___or ____, whichever is ______, the aircraft enters speed priority override mode.
1.1 or stall +9 kts, greater
What 3 things happen when the aircraft enters speed priority override mode?
airspeed-to-pitch is enabled
airspeed command is set to the approx. best climb speed,
a speed that will achieve a CL of 1.0
The warning “best climb speed override” is sent to the GCS
Under what 2 conditions will the aircraft exit speed priority mode?
- airspeed is not less than 2kias below best climb speed and the aircrafts VSI is > the altitude-to-pitch controller’s commanded VSI
- aircraft is above the commanded altitude and KIAS is above min airspeed command (CL = 1.25)
What is the first level of stall protection provided by the autopilot and how does it work?
aileron tip stall override. automatically decambers the ailerons proportionally if AOA increases above +5 units to prevent wingtips from stalling.
Aileron tip stall override is activated when _____ or _____. It is only deactivated if ______ and _____.
cruise mode is off or stall protect is on. cruise mode is on AND stall protect is off
Aileron tip stall’s added deflection the ailerons varies from ___ additional deflection at ___AOA and ___ of aileron deflection at ___AOA.
0 at 5 and 8 at 9
TRUE or FALSE. Added aileron deflection from the tip stall override function is added to any pilot commanded aileron deflection?
TRUE
Stall protect feature attempts to ______ by ________.
prevent stall by limiting aircraft AOA
Stall protect is turned on/off by the pilot, but only takes effect at speeds below __KIAS and automatically turns off at speed greater than __KIAS.
120, 120
Stall protect automatically turns on when airspeed is below ___KIAS and ____is engaged
120, autopilot
TRUE or FALSE. Stall protect will not turn on, if the pilot has it commanded off and with no autopilot engaged.
TRUE
Stall protect prevents stall by deflecting ruddervators ______ when AOA exceeds a threshold value of ___. Stall protect disengages when the AOA is less than ___.
down, 7 , 3
Turning on stall protect automatically turns on _________.
cruise mode
The roll limit override feature uses CL ____ to maintain a safety margin between the aircrafts _____ and its _____ due to roll angle.
1.25, indicated airspeed and stall speed
Roll limit override is automatically activated when (4 conditions)
airspeed or heading hold is on, stall protect is on, or the aircraft is in LOS link mode
Stall speed _____ as roll angle ______.
increases, increases
What autopilot feature is always enabled and what purpose does it serve?
Sideslip protect. keeps the aircraft from entering an unwanted sideslip condition during turns.
The autopilot calculation of aircraft weight is based on ______, minus ________, minus ______.
ramp weight entered by pilot, fuel burned, weight of released stores
Why is it important to correctly enter ramp weight in presets?
various flight factors are calculated based on this data such as CL and stall speed
What functions are turned off when landing configuration is commanded?
Airspeed/Heading/Altitude hold, preprogram mode and stall protect
If a rack switch is required, which 4 items must match between pilot and sensor stations?
Flap lever -3 to +3
Condition lever 0-5
Throttle 10-100
Engine Speed >= 96%
