Flight Control Systems PDF

# Flight Control Systems ## Hydraulic Systems 1. Which Hydraulic System(s) normally power the primary flight controls? [FCOM 9.20.1] - Hydraulic System A and B 2. What powers each primary flight control surface with the loss of both Hydraulic Systems A and B (manual reversion)? [FCTM 8.46]...

# Flight Control Systems ## Hydraulic Systems 1. Which Hydraulic System(s) normally power the primary flight controls? [FCOM 9.20.1] - Hydraulic System A and B 2. What powers each primary flight control surface with the loss of both Hydraulic Systems A and B (manual reversion)? [FCTM 8.46] - Ailerons: Mechanically through cables - Elevator: Mechanically through cables - Rudder: Standby Hydraulic System 3. With the loss of Hydraulic System B, how are the Leading Edge (LE) Flaps and Slats and the Trailing Edge (TE) Flaps operated? [FCOM 9.20.1] - Leading Edge (LE) Flaps and Slats: Standby Hydraulic System - Trailing Edge (TE) Flaps: Electrically 4. With a jammed or restricted Aileron System, how is roll controlled? [FCOM 9.20.3] - Force applied to the First Officer's control wheel provides roll control from the spoilers 5. With a jammed or restricted Spoiler System, how is roll controlled? [FCOM 9.20.3] - Force applied to the Captain's control wheel provides roll control from the ailerons 6. Why is aileron trim prohibited with the autopilot engaged? [FCOM 9.20.3] - With the autopilot engaged, aileron trim is not reflected in the control wheel position - The autopilot overpowers the trim and holds the control wheel where it is required for heading/track control - Any aileron trim applied when the autopilot is engaged can result in an out of trim condition and an abrupt rolling movement when the autopilot is disengaged 7. How many degrees of control wheel displacement initiates Flight Spoiler deflection? [FCOM 9.20.4] - More than 10° (approximately) 8. What does an illuminated FEEL DIFF PRESS light indicate? [FCOM 9.10.3, 9.20.7] - Excessive differential pressure in the Elevator Feel Computer - Caused by either Hydraulic System A or B loss or the Elevator Feel Pitot System failure 9. If either the Captain's or First Officer's control column is jammed, how would you regain elevator control? [FCOM 9.20.6] - Applying force against the jam will breakout either the Captain's or First Officer's control column - Whichever column moves freely after the breakout can provide adequate elevator control 10. When would you use the Elevator Jam Landing Assist system? [FCOM 9.20.6] - When there is a jam in the aft elevator control mechanism 11. How does the Elevator Jam Landing Assist system aid when a landing is made with a jammed elevator? [FCOM 9.20.6, 9.20.7] - During approach and landing, the Elevator Jam Landing Assist system uses the flight spoilers for small changes to the flight path - A push on the control column causes the spoilers to extend farther, increasing the descent rate - A pull on the control column causes the spoilers to retract, decreasing the descent rate 12. How do you activate the Elevator Jam Landing Assist system? [FCOM 9.20.6] - Elevator Jam Landing Assist switch must be selected ON and - Actual flap position must be 1 or greater and - Autopilot must be disengaged 13. How is stabilizer trim accomplished? [FCOM 9.20.8, 9.20.9] - With the autopilot engaged, stabilizer trim is accomplished through the autopilot stabilizer trim circuit - Main Electric Stabilizer Trim switches on each control wheel actuate the electric trim motor through the main electric stabilizer trim circuit when the airplane is flown manually - Manual stabilizer control is accomplished through cables which allow the pilot to position the stabilizer by rotating the stabilizer trim wheels 14. When is the Autopilot Trim or Main Electric Stabilizer Trim active in the high speed mode and low speed mode? [FCOM 9.20.8] - High Speed when Flaps are extended - Low Speed when Flaps are retracted 15. What is the purpose of the STAB TRIM Cutout (PRI and B/U) switches on the Control Stand? [FCOM 9.20.8] - If either switch is positioned to CUTOUT, the following trim inputs are disconnected from the stabilizer trim motor: - Autopilot Trim - Main Electric Stabilizer Trim - Speed Trim System (Speed Trim function and MCAS function) 16. If the STAB TRIM Cutout switches have been set to CUTOUT, how would you trim the stabilizer? [FCOM 9.20.9] - Manually trim by rotating the stabilizer trim wheel 17. What is the purpose of the Control Column Actuated Stabilizer Trim Cutout switches? [FCOM 9.20.8] - When control column movement opposes trim direction, the Control Column Actuated Stabilizer Trim Cutout switches - interrupts operation of Main Electric Stabilizer Trim, Autopilot Trim and the Speed Trim function - Forward control column movement interrupts MCAS nose up trim command - Aft control column movement does not affect MCAS nose down trim commands 18. What is the purpose of the Flight Control Computer (FCC) software column cutout function? [FCOM 9.20.8] - Adds a layer of redundancy to mitigate a latent failure of the Control Column Actuated Stabilizer Trim Cutout switches - Cuts out automatic stabilizer commands beyond the cutout position of the Control Column Actuated Stabilizer Trim Cutout switches - Main Electric Stabilizer Trim commands are not inhibited 19. What is the purpose of the STAB TRIM switch on the aft electronics panel? [FCOM 9.20.8] - When positioned to OVRD, allows operation of the Main Electric Stabilizer Trim regardless of control column position 20. What will occur if you attempt to takeoff with the stabilizer trim out of the green band? [FCOM 9.20.9] - An intermittent horn sounds (Takeoff Warning horn) - TAKEOFF CONFIG light illuminates 21. What does the Speed Trim System (STS) provide? [FCOM 9.20.9] - Speed and pitch stability augmentation - Speed stability augmentation is provided by the Speed Trim function in the Speed Trim System - Pitch stability augmentation is provided by the MCAS function in the Speed Trim System 22. Will the Speed Trim System (STS) operate when the autopilot is engaged? [FCOM 9.20.9] - No 23. What does Speed Trim function accomplish? [FCOM 9.20.10] - Improve flight characteristics during operations with low gross weight, aft center of gravity and high thrust when the autopilot is not engaged - Return the airplane to a trimmed speed by commanding the stabilizer in a direction opposite the speed change 24. What are the conditions for Speed Trim function to operate? [FCOM 9.20.10] - Up to Mach 0.68 - 10 seconds after takeoff - 5 seconds following release of the Main Electric Stabilizer Trim switches - Autopilot not engaged - Sensing of trim requirement 25. What speed does the Speed Trim function control the stabilizer trim motor? [FCOM 9.20.10] - High rate with Flaps extended - Low rate with Flaps retracted 26. What does the Maneuvering Characteristics Augmentation System (MCAS) function accomplish? [FCOM 9.20.11] - MCAS is a pitch stability augmentation function designed to operate at elevated Angles Of Attack (AOAS) - The purpose is to increase control column forces by commanding the stabilizer in the nose down direction at elevated AOAS 27. What are the conditions for Maneuvering Characteristics Augmentation System (MCAS) function to operate? [FCOM 9.20.11] - AOA above threshold - Autopilot not engaged - Flaps up - Up to Mach 0.84 - 10 seconds after takeoff 28. Will MCAS activate with an autopilot engaged? - No 29. What speed does the Maneuvering Characteristics Augmentation System (MCAS) function control the stabilizer trim motor? [FCOM 9.20.11] - High rate 30. Where does the Flight Control Computer (FCC) get its data to activate MCAS? [FCOM 9.20.11] - Both AOA vanes 31. How can MCAS stabilizer operation be inhibited and reversed? [FCOM 9.20.11] - By using pilot Main Electric Stabilizer Trim switches 32. After Main Electric Stabilizer Trim is used to inhibit Speed Trim or MCAS, how long is the delay before Speed Trim or MCAS will operate if needed again? [FCOM 9.20.10, 9.20.11] - Inhibited for 5 seconds - After the 5 second inhibit, the Stabilizer will be commanded to the specified value based on detected AOA and Mach 33. Why does the MCAS function contain logic that limits the amount of nose down stabilizer trim movement? [FCOM 9.20.11] - To preserve elevator authority for pitch control 34. What occurs when MCAS has reached its command limit logic nose down stabilizer trim limit? [FCOM 9.20.11] - SPEED TRIM FAIL light illuminates - Speed Trim System (Speed Trim function and MCAS function) is inhibited for the remainder of the flight 35. What causes the SPEED TRIM FAIL light to illuminate and remain illuminated after a FLT CONT Master Caution is reset? [FCOM 9.10.3, 9.20.10] - Failure in the Speed Trim System (Speed Trim function or MCAS function) - If one function fails, the other function is inhibited 36. What if you only get the FLT CONTROL Master Caution on RECALL and see this light, and the light extinguishes when the Master Caution system is reset? Would you perform the QRH Non-Normal Checklist in this scenario? [FCOM 9.10.3] - Single FCC channel failure - No 37. Can the pilot override the Speed Trim System (Speed Trim function and MCAS function) nose up or nose down stabilizer trim commands? - Yes, by using the Main Electric Stabilizer Trim to oppose STS/MCAS commands - Control column cutout switches inhibit electric trim commands - Exception: does not interrupt MCAS nose down stab trim commands 38. What is the purpose of the Elevator Feel Shift (EFS) module? [FCOM 9.20.13] - Increases Hydraulic System A pressure to the Elevator Feel and Centering Unit during a stall - This approximately doubles control column forces 39. What protection do the Flight Control Computers (FCCs) provide with regards to stall identification? [FCOM 9.20.13] - Protection against possible runaway stabilizer conditions caused by erroneous FCC stabilizer trim commands - The FCCs continuously monitor each other's stabilizer trim commands, - If erroneous commands are detected, stabilizer trim commands, autopilot trim commands, and Control Wheel Steering (CWS) trim commands are stopped and inhibited for the remainder of the flight for that FCC. 40. What does the Autopilot Elevator Monitor protect against? [FCOM 9.20.13] - Erroneous elevator commands that can result in erroneous autopilot stabilizer trim commands 41. What does the Stabilizer Cross-FCC Trim Monitor protect against? [FCOM 9.20.14] - Erroneous stabilizer trim commands 42. What does illumination of a STAB OUT OF TRIM light indicate? [FCOM 4.10.20] - In-flight - Autopilot is not properly trimming the stabilizer - Partial failure of a Flight Control Computer - Illuminates only with autopilot engaged - Remains extinguished when the autopilot is not engaged - On the ground - Partial failure of a Flight Control Computer - Illuminates after landing when groundspeed is less than 30 knots 43. What does illumination of a FLT CONTROL LOW PRESSURE light indicate? [FCOM 9.10.2] - Low Hydraulic System (A or B) pressure to ailerons, rudder and elevator - Deactivated when associated FLIGHT CONTROL switch is positioned to STBY RUD and standby rudder shutoff valve opens 44. How can the standby rudder system be pressurized? [FCOM 9.10.1, 9.20.16] - By either Flight Control switch in the STBY RUD position or - Automatically during takeoff or landing or - Automatically by the Force Fight Monitor 45. What does the illumination of the STBY RUD ON light indicate? [FCOM 9.10.2] - Standby rudder system is commanded on to pressurize the standby rudder power control unit 46. What is the purpose of the Force Fight Monitor (FFM) on the Main Rudder PCU? [FCOM 9.20.15] - Detects opposing pressure (force fight) between A and B actuators - This may occur if either Hydraulic System A or B input is jammed or disconnected 47. How would you know that the Force Fight Monitor (FFM) has sensed a jammed rudder? [FCOM 9.20.15] - Illuminates the STBY RUD ON, Master Caution, and Flight Control (FLT CONT) lights - The FFM output is used to automatically turn on the Standby Hydraulic pump and open the standby rudder shutoff valve to pressurize the standby rudder PCU 48. What does the Rudder Trim control switch do? [FCOM 9.20.16] - Electrically repositions the Rudder Feel and Centering Unit and displaces the Rudder pedals 49. Will the rudder trim operate with the autopilot engaged? - Yes 50. How many yaw dampers does the yaw damper system consist of? [FCOM 9.20.16] - Main Yaw Damper - Standby Yaw Damper 51. What protections does the yaw damper provide? [FCOM 9.20.16] - Dutch roll prevention - Gust damping - Turn coordination 52. When will the Yaw Damper switch automatically move to the OFF position? [FCOM 9.20.16] - SMYD senses a yaw damper system fault or - SMYD senses that the yaw damper does not respond to a command or - B FLT CONTROL switch is positioned to OFF or STBY RUD 53. When is the Standby Yaw Damper available? [FCOM 9.20.16] - During manual reversion (loss of Hydraulic System A and B) when both FLT CONTROL switches are positioned to STBY RUD - and the YAW DAMPER switch is reset to ON 54. The loss of Hydraulic Systems A and B will render which spoiler panels inoperative? [FCOM 9.20.21] - All Spoiler panels (Flight and Ground spoilers) 55. What happens when electrical power is lost to the Spoilers Control Electronics (SCE) Unit? [FCOM 9.20.18] - All spoilers are inoperative and will retract if extended 56. Which Flight Control switch(es) are used for maintenance purposes only? [FCOM 9.10.1, 9.10.2] - SPOILER A and B 57. During landing or rejected takeoff, when would the auto speedbrake system operate if the speedbrake lever was in the down position? [FCOM 9.20.20] - Main landing gear wheels spin up (more than 60 kts) - Both thrust levers are retarded to IDLE - Reverse thrust levers are positioned for reverse thrust 58. What does illumination of a SPEED BRAKE DO NOT ARM light indicate? [FCOM 9.10.9] - Fault within the auto speedbrake system 59. When does the SPEED BRAKES EXTENDED light illuminate? [FCOM 9.20.18] - In-flight, the light illuminates to warn the crew that the speedbrakes are extended while in the landing configuration or below 800 feet AGL - It also illuminates if the speedbrakes are extended and the thrust levers are greater than idle for 15 seconds, or a thrust lever is greater than approximately 40 degrees for 3 seconds - On the ground, the light illuminates when hydraulic pressure is sensed in the ground spoiler shutoff valve with the speedbrake lever in the DOWN position 60. What would cause the Leading Edge (LE) FLAPS TRANSIT (amber) light to illuminate? [FCOM 9.10.12, 9.10.13] - Any LE device in transit - Any LE device not in programmed position with respect to TE Flaps - Two (2) or more LE Flaps or Slats moved from their commanded position 61. What are the normal landing flap settings? [FCOM 9.20.22] - Flaps 15, 30, 40 - Flaps 15 is normally limited to airports where approach climb performance is a factor 62. Why do we have Flap gates at Flap positions 1 and 15 on the Flap track? [FCOM 9.10.11] - Prevent accidental Flap lever movement beyond: - position 15, to check Flap position for a normal Go Around - position 1, to check Flap position for a One-Engine-Inoperative Go Around 63. What is the purpose of the Flap Load Relief function? [FCOM 9.20.22] - Protects the Trailing Edge Flaps from excessive air loads - When the Flap Load Relief function activates, the FLAP lever does not move, but the flap position indicator shows flap retraction and re-extension 64. How far do the Flaps move during load relief? [FCOM 9.20.22, 9.20.23] - One Flap setting lower than selected Flap setting (from 40 to 30, from 30 to 25, from 25 to 15, from 15 to 10, from 10 to 5) 65. What does illumination of an AUTO SLAT FAIL light during Master Caution RECALL indicate? Would you perform the QRH Non-normal checklist in this scenario? [FCOM 9.10.4] - Failure of a single Stall Management Yaw Damper (SMYD) - No 66. With the failure of Hydraulic System B, is it possible to extend/retract the Leading Edge (LE) Flaps & Slats and Trailing Edge (TE) Flaps? [FCOM 9.20.23] - Yes, using the alternate flap extension - Leading Edge (LE) Flaps & Slats extend only (uses Standby Hydraulic System) - Trailing Edge (TE) Flaps extend and retract (uses electric motor) 67. What happens when you place the ALTERNATE FLAPS master switch to ARM? [FCOM 9.20.23] - Activates the Standby Hydraulic Pump - Closes the Trailing Edge Flap Bypass Valve - Arms the ALTERNATE FLAPS position switch 68. What happens if you momentarily place the ALTERNATE FLAPS position switch to the DOWN position? [FCOM 9.20.23] - Extends the LE Flaps and Slats using standby hydraulic pressure to the full extend (FULL EXT) position 69. When using the alternate flap extension method, how long is the extension time from Flaps Up to Flaps 15? [QRH 9.40] - About 2 minutes 70. What is an asymmetry condition? [FCOM 9.20.25] - If a device on one wing does not align with the symmetrical device on the other wing 71. What is a skew condition? [FCOM 9.20.25] - Symmetrical TE flaps do not operate at the same rate causing the panels to twist during extension or retraction 72. When using alternate flap extension, is asymmetry or skew protection provided? [FCOM 9.20.23] - No 73. What protection does the Flap Slat Electronic Unit (FSEU) provide when it detects a TE asymmetry or a skew? [FCOM 9.20.25] - Closes the TE flap bypass valve - Displays a needle split on the flap position indicator - Shows position of left and right wing Trailing Edge Flaps 74. What protection does the Flap Slat Electronic Unit (FSEU) provide when it detects an uncommanded motion of Leading Edge (LE) devices on one wing? [FCOM 9.20.25, 9.20.26] - Shuts down the LE control and illuminates the amber LE FLAPS TRANSIT light - To prevent uncommanded motion from occurring on the LE devices during cruise, the FSEU maintains pressure on the retract lines and depressurizes the extend and full extend lines 75. What protection does the Flap Slat Electronic Unit (FSEU) provide when it detects an uncommanded motion of Trailing Edge (TE) devices? [FCOM 9.20.26] - Shuts down the TE drive unit by closing the TE flap bypass valve - The TE Flap shutdown cannot be reset