Presentation on theme: "Cessna Citation II Flight Controls"— Presentation transcript:
1Cessna Citation II Flight Controls Dr. Kurt BarnhartAST 473
2Flight Controls Overview Primary Flight Controls Ailerons Rudder Elevator-Manually actuated by rudder pedals and control column-Can be immobilized by control locks on ground-Mechanical Trim in all three axis + elec. Elev. trim
3Flight Controls Secondary Flight Controls- Electric flaps Hydraulic speedbrakes-Stall Warning- stall strip on leading edge of each wing- aerodynamic buffet-Yaw damping- autopilot
4Flight ControlsGeneral- control inputs are transmitted via cables and bellcranksRudder pedals are 3 position adjustable via a spring latch on rudder pedals-sideFences on inboard edge of rt. Aileron and inboard edge of left aileron trim tab- air ailerons in returning to neutral
5Flight ControlsRudder, rt. Elevator and left aileron- mechanical trim tabs actuated from cockpitPilot’s and co-pilot’s (optional) cnt’l wheel have a pitch trim switchControl locks- on primary flight controls and throttles- operated from cockpit:Neutralize controls & idle throttlesRotate handle (CW) 45 deg. & pull until handle returns to horizontal- to release- rotate CCW & push in until horizontal- DO NOT TOW WHEN LOCKED!
6Flight ControlsTrim systems- standard mechanical- cockpit actuated & indicatedRudder trim- only servo tab on aircraft- deflects at half rate of rudder- aids pilot movementElec. Trim- outboard horn of ea. cnt’l wheel- pilot’s inputs overrides co-pilotsAP/TRIM DISC on cont’l wheel or pulling PITCH TRIM CB- controls runaway trim
7Flight Controls Secondary control Fowler flaps- 0 – 40 deg., mechanically interconnected- prevents flap asymmetry and allows operation by one elec. ActuatorSpeedbrakes- slotted panels on top & bottom of ea. Wing fwd. of flaps:Used for increased descent ratesIncreased drag and lift destruction on lndg.
8Flight Controls Flaps- Detented @ 15 deg. Position (T/O & lndg.) Handle movement actuates switch- energizes two motors- position mechanically indicated on cockpitMotors interconnected mechanically & actuated mechanically- normally operate in unison but one motor provides sufficient for normal operation
9Flight Controls Flap Operation- Moving flap handle- activates 1 of 2 switches in center pedestal- supplies pwr. To motorsAt selected position- position indicator mechanically repositions cnt’l sw. to remove pwr. From motorsMechanical drag- holds flaps in positionLimit sw.- prevent overrun up or downNo D.C.- N Flaps- fail in positionTravel time- 6 sec. 0 -full down, 3 sec. back
10Flight Controls Speedbrakes- 2 positions- up & down 2 hyd. Actuators Solenoid valve4 speedbrake segmentsSPD BRAKE EXTENDED annunciatorPedestal control switch
11Flight Controls Speedbrake Operation: Placing speedbrake sw. in EXTEND-Closes hyd. Bypass valve (HYD. PRESS ON lt.)Energizes speedbrake solenoid valve- press. To speedbrakes- forces them out of mech. DownlocksSafety valve- also closed2 position switch- spring loaded to retract- (can be held ext. above 85% N(2)- early models only)At full travel press. Builds, bypass valve opens, annunciator goes out- solenoid valve neutralizes- trapping hyd. Press in actuators- holding extension
12Flight Controls Speedbrake Retraction- Place switch in retract Hyd. Sys. PressurizesSafety valve opens (de-energizes)Solenoid valve directs press. For retractionAnnunciator goes out- “Boards” retract into mechanical locks- system depressurizesLocks- 2 pins on lower board panel- hydraulically forced into retaining clips.
13Flight ControlsMost models- if throttles above 85% N(2)- solenoid valve and bypass valve position for retractionSafety valve- if elec. Failure w/ boards out- spring loads open- allows boards to blow downIf elec. Failure w/ boards retraction- no actuation possible
14Flight ControlsStall Warning- stall strip on leading edge of ea. Wing for aerodynamic buffetBuffet- VS(1) +10 (clean) and VSO + 5 (dirty)
15Flight Controls Yaw Damping- function of autopilot Consists of automatic application of rudder against transient motion in YAWYD automatically engaged w/ autopilotNot required for flightCan be engaged w/o autopilot by pushing YD ENGAGE sw. on autopilotDisengaged by pressing AP/TRIM DISC on cnt’l wheel