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650 Captain's Questions > Flight Controls > Flashcards

Flight Controls Flashcards

1
Q

The fly-by-wire flight control system has different modes of operation. What are they?

A

Normal, Alternate, Direct, Backup, and Maintenance

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2
Q

During taxi, Blue CAS - “FCC Single Channel Fail”.

Can you dispatch?

A

Yes.

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3
Q

What keeps the flight control surfaces ‘locked’, in the absence of a gust lock?

A

Damped bypass mode in which hydraulic pressure is trapped to resist movement of surface (up to 60 kts).

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4
Q

An Amber CAS - “Spoiler Panel Fail” illuminates in flight.

What should pilot do?
Any limitation with this failure?

A

Complete QRH checklist for Spoiler Panel Failure.

Max airspeed of 285 kts/0.90 Mach.

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5
Q

How many ADS must be heated for NORMAL mode on the FCCs?

A

2

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6
Q

How can pilot(s) select the STBY ADS?

A

Pilot selection of the STBY ADS is not available. It’s ONLY available to the Standby Flight Display or automatically to DUs 1, 2, 3, or 4 during certain avionics and power failures

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7
Q

Amber CAS - “FCC Alternate Mode”.

What would cause this?

A 
< 2 valid Inertial Ref signals, one of which MUST be from an IRU
Or,
< 2 valid ADS
Or,
Loss of comm from FCC to HSCU
Or, 
Yaw Damper Failure
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8
Q

Amber CAS - “FCC Alternate Mode” in flight.

Can Flight Controls be recovered in this Mode?

If so, how?

A

Yes, if the problem that put FCCs in to the mode is corrected.

Press the FLT CTRL RESET iaw the QRH/AFM checklist

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9
Q

What is the purpose of the A/P DISC Switch?

A
  1. Disengages the autopilot
  2. Stops runaway trim
  3. Silences the AP DISC warning
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10
Q

How can the pilot disconnect the Auto Pilot, other than with the A/P DISC Switch?

A
  1. Physically override the flight controls
  2. Select AP OFF on the Guidance Panel
  3. Use and of the pitch trim switches
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11
Q

Name the four flight control modes

A
  1. Normal
  2. Alternate
  3. Direct
  4. Backup
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12
Q

What happens if all four FCC channels are invalid?

A

System reverts to the “Direct” mode.

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13
Q

What happens if all four FCC channels are unable to compute the control law?

A

Backup Flight Control Unit (BFCU) will activate to provide a ‘get home’ capability.

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14
Q

What’s the function of the FLT CTRL RESET switch?

A

Used to reset flight control computers and control surface actuators when directed by a checklist.

Removes lockouts for the FCCs

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15
Q

When are automatic ground spoilers not available?

A

Not selected to ARM, no WOW or wheel spin up.

In DIRECT or BACK UP flight control laws.

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16
Q

What is the return to zero feature of the stab?

A

When the flaps and stab reach 0° at simultaneously after landing when pilot retracts the flaps.

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17
Q

Name the primary flight controls.

A

Ailerons, elevators, rudder, and multi-function spoilers (i.e., mid-board and outboard spoiler panels).

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18
Q

Name the secondary flight controls.

A

Horizontal stabilizer, flaps, and inboard spoilers

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19
Q

How is pitch trim accomplished?

A

From either yoke mounted switch or center console mounted BACKUP PITCH trim switch

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20
Q

What’s the purpose of A/P DISC switch?

A

It disengages the autopilot and stops runaway trim in all three axes.

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21
Q

What’s the function of FLT CTRL RESET switch?

A

Used to reset flight control computers and REUs/control surface actuators when directed by a checklist.

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22
Q

What effect does loss of one hydraulic system have on the flight controls?

A

Loss of one spoiler pair Airspeed limitation 285/.90

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23
Q

What is common among primary flight control surfaces?

A

They have two (2) actuators and two (2) REU’s for each primary flight control surface except outboard spoilers. One of the actuators is an EBHA

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24
Q

What are control laws?

A

Software in the FCC’s that translate electrical commands from cockpit control sensors and aircraft motion sensors (inertial/air data) into flight control surface commands

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25
How many computers control the flyby-wire flight control system?
Three (3) computers: two (2) flight control computers for normal operation and Backup Flight Control Unit in case both flight control computers fail.
26
What’s the minimum number of FCC channels that can command all flight control surfaces on the aircraft.
One.
27
What’s the purpose of Backup Flight Control Unit (BFCU)?
It’s designed to provide what Gulfstream calls “get home capability” if both primary FCC’s fail.
28
What happens once the BFCU becomes active?
It communicates directly with EBHA remote electronics units (REU’s) on separate backup data buses, and is active for the duration of flight.
29
Describe the Electric Backup Hydraulic Actuator (EBHA).
It’s a special actuator with self contained electric motor/pump and hydraulic reservoir.
30
What type of sensor input is provided to FCC’s?
Input from IRS’s, AHRS, ADS’s and radio altimeters
31
Describe the AOA limiting feature.
As AOA approaches 0.75, the PLI appears. As it increases toward 0.93, AOA limiting feature is entered. The stick shaker will activate at 0.94, but In this mode, full aft column input commands the maximum nose angle of-attack of 0.96.
32
Which mode protects from surface flutter and separation that would occur greater than Vdive speed?
High speed protection It limits nose down authority by 75%. Above 60 degrees of bank, protection is faded out.
33
Will flight controls enter high speed protection law while autopilot is engaged?
No. It's inhibited with AP connected. Also, you can't engage AP if the flight controls are in high speed protection mode.
34
What’s the auto-retract feature?
It retracts speed brakes at high power settings (90% or higher)
35
Describe requirements for the flight control mode to remain in normal.
Normal mode requires 1 FCC channel, 2 air data (multifunction probes) and 1 inertial data source. HSCU must also be capable of receiving FCC commands on one of its two (2) channels.
36
What happens if all four (4) FCC channels are invalid?
Flight control system reverts to direct mode
37
What happens if all four (4) FCC channels are unable to compute the control law?
Backup Flight Control Unit (BFCU) activates to provide “get home” capability
38
What term is used to describe the amplification, attenuation, boosting, or magnification that’s applied to the forward signal to achieve the desired aircraft response?
Gain
39
The normal mode has five (5) primary operating sub modes. What are they?
On ground, Takeoff and landing, Cruise, AOA limiting, and High speed protection
40
What sub mode is the flight control system in when flying with the gear and/or flap handle down and autopilot disengaged?
Takeoff and landing mode. Here’s a clue: you’ll see a number in the pitch trim digital readout.
41
Describe how the flight control system operates in alternate mode.
Pitch, roll, and rudder pedal inputs are multiplied by a set of fixed gains to command the elevator, ailerons, roll spoilers, and rudder
42
How many sets of gains are associated with degraded flight control modes?
Two: one set of generally smaller numbers used when flap handle and gear handle are up (and aircraft is presumed to be traveling at higher speed – 340 kts), and a set of generally larger numbers that are used if flap handle or gear handle is down (and aircraft is presumed to be traveling slower – 250 kts).
43
What functions with the ailerons to improve roll
Mid and outboard spoiler panels extend to a maximum of 55°
44
Name the two types of flight control actuators.
Hydraulic Actuator (HA) and Electric Backup Hydraulic Actuator (EBHA)
45
Describe HA operation.
It’s controlled electrically by its Remote Electronics Unit (REU) and uses hydraulic power to move the control surface.
46
What’s the function of REU?
It’s mounted on associated hydraulic manifold, averages FCC1 and FCC2 commands and electrically controls a valve in hydraulic manifold to control actuator position to match FCC commands.
47
What additional features do EBHA’s have?
Able to operate in electric backup mode if normal source of hydraulic pressure is lost or operate in MCE direct control mode for failure of both REU’s
48
Describe EB operation.
Within EB hydraulic manifold, an electric motor turns a hydraulic pump that draws fluid from self-contained reservoir: it acts like third hydraulic system. The fluid is trapped from normal source of hydraulics.
49
What’s the purpose of Motor Control Electronics (MCE)?
EBHA REU normally controls MCE when EBHA is in EB (electric backup) operation and MCE controls operation of backup electric motor. For REU failure, MCE can directly control the EBHA.
50
What does the color of HA or EBHA status border indicate on flight control synoptic page?
Green for active/healthy and amber for inactive/unhealthy
51
Which actuator has an electric backup mode?
EBHA
52
When does the EB mode function?
Only if both HA and EBHA systems cannot function in their normal hydraulic mode. There will never be mixed operation where an HA is operating in its normal hydraulic mode, and EBHA is in electric backup. This mode is designed to operate when there’s a complete loss of hydraulics to critical flight control surface.
53
What action is required for a jam in cockpit roll controls?
A force-based roll override device under cockpit floor is provide to overpower and isolate the jammed portion of roll controls. Activation of roll override device is accomplished by applying approx 10 lbs to overcome breakout force of roll override device. Roll control is recovered by using unrestricted side of roll controls. IMPORTANT: Sensor input from roll controls is averaged.
54
What pilot action is required for an aileron surface, elevator, or spoiler surface jam?
Both pilot and copilot roll control wheels remain available to control the unrestricted aileron and spoiler surfaces: fly normally and trim, and refer to QRH.
55
What happens when ROLL MOTOR CONTROL switch is selected to OFF?
Roll trim switches bypass control columns and send signals directly to FCC's. The only downside to this is lack of corresponding control wheel movement.
56
What’s the primary purpose of ROLL MOTOR CONTROL switch?
To remove electrical power from Roll Control Motor (under the floor) in the unlikely event of Roll Motor Control runaway or mechanical jam,... and at the same time enable direct trimming of ailerons via the FCC's
57
What action is required for a jam in cockpit elevator controls?
A force-based elevator override device under cockpit floor is provided to isolate the jammed portion of elevator controls. Activation of this device is accomplished by applying approx 40lbs force to overcome breakout force of elevator control device. Elevator control is recovered by using the unrestricted elevator surface.
58
Under what condition would BACKUP PITCH switch have to be used?
Loss of input from both FCCs (ie: Backup Mode). If this were to occur, BACKUP PITCH switch bypasses FCCs and controls the horizontal stab directly at a constant, minimum rate. (0.15 degrees/min)
59
What pilot action is required in the unlikely event that rudder pedals become mechanically jammed?
The pilots would have to use other flight controls or differential power to control the aircraft: there is no breakout capability.
60
What happens with selection of AUTO CENTER switch?
FCCs electronically direct rudder trim actuation system to center the rudder.
61
What component is responsible for moving the stabilizer surface?
Horizontal Stabilizer Trim Actuator (HSTA), which is a dual electric motor (Main AC buses)
62
Describe HSTS operation in primary or normal mode.
FCCs provide rate commands to Horizontal Stab Control Unit (HSCU)
63
True/False: Standby mode of Horizontal Stab, indicated by an amber Stabilizer Failed CAS message, occurs when you lose the ability to trim the stab (e.g., dual motor failure, jam or dual HSCU channel failure).
True: In STBY, you're trimming elevators as opposed to horizontal stab and there's no off-load feature. Don't use backup pitch trim switch.
64
When is backup mode of HSTS entered (Amber CAS: Stab Primary Trim Fail)?
With loss of input from both FCCs (ie Backup Mode). In this mode, BACKUP PITCH switch on pedestal is used to move the stab.
65
What is the elevator off-load feature?
Once elevator deflection exceeds a preset value for predetermined amount of time, horizontal stabilizer and elevators move simultaneously: horizontal stab moves to the new trim position as elevators move to “faired” position (0 degrees relative to horizontal stab surface). It’s controlled or commanded from FCC’s to reduce elevator deflection.
66
Describe how the flaps operate.
Manually operated, electrically controlled, hydraulically powered, and mechanically actuated
67
What happens if there’s any sort of malfunction (e.g., flap jam, asymmetry, runaway, etc.) during flap operation?
Flap motion is interrupted
68
When do the spoilers function?
Six spoiler panels (three on each wing) operate as speed brakes/air brakes and ground spoilers; four operate as flight spoilers (i.e., two outboard)
69
What is maximum Spoiler deflection?
55°
70
What’s the maximum deflection with full speed brake extension?
30° in-flight or 55° on ground with flap handle not up
71
What will happen if after descending with speed brakes extended, you level off and power advances before you retract SB?
As power is increased during level off, the blue Speed Brake Extended message changes to amber and you get the associated two bong caution chime
72
What happens if speed brakes are extended and pilot advances throttles to a high power setting?
Above 90% throttle setting, the speed brakes automatically retract although speed brake handle remains in extended position, and an amber Speed Brake Auto Retract message displays.
73
What function do ground spoilers perform on touchdown or during rejected takeoff?
They provide a method for full and automatic deployment of all spoiler panels in order to reduce lift and increase braking effectiveness on ground.
74
What are the requirements for ground spoiler deployment?
Switch must be ARMED, power levers - idle, wheel spin up >47 kts OR WOW-Gnd
75
What happens when GPWS/GND SPLR FLAP ORIDE switch is selected to ON?
Automatic ground spoiler deployment occurs with wheel spin up if flaps < 22° and all other parameters are satisfied. GPWS voice alarm, “TOO LOW, FLAPS”, is inhibited.
76
How many times can the flight crew press the FLT CNTL RESET switch?
There’s no restriction. Crew should wait 10 seconds between activation though.

650 Captain's Questions (15 decks)

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