Systems - Flight Controls

Question 1

All flight control surfaces are FBW except:

Answer 1

Ailerons

Question 2

Briefly explain the signal path for a pitch change from control column to elevator in normal mode. Direct mode?

Answer 2

Normal Mode: Control input to P-ACE. P-ACE talks with FCM, which takes into account external factors (airspeed, AoA, etc) to generate an appropriate response that is sent back to the P-ACE. The P-ACE then then commands that response to the PCU, which physically moves the control surface(s).

Direct Mode: Same as above, however the FCM is removed from the loop, resulting in loss of higher level functions.

Question 3

What is the purpose of the ACE?

Answer 3

Actuator Control Electronics. Connects the control column electronically to the respective control surface. Essentially an Analog to Digital Converter.

Question 4

What is the purpose of the FCM?

Answer 4

Flight Control Module. Provides software-based assistance to control inputs based on external data (airspeed, AoA, etc).

Question 5

Name a few Higher Level Functions.

Answer 5

Elevator Control Laws scheduling with airspeed.

Auto-Thrust compensation with elevator

Angle-of-Attack limiting with elevator offset.

Rudder airspeed gain scheduling and stroke limiting

Yaw Damper and turn coordination via AFCS

Rudder Flight Authority

Roll spoiler scheduling with airspeed and speed brake deployment.

Configuration change compensations with horizontal stabilizer due to speed brake actuation

Question 6

Flaps are ____ actuated through the SF-ACE.

Answer 6

Electrically

Question 7

What is the difference between Flaps 4 and Flaps 5?

Answer 7

Lever is gated vs detent. Also, logic based to tell computer what phase you’re in (takeoff/landing).

Question 8

What flap settings are used for takeoff? Landing? Go-Around?

Answer 8

Takeoff: FLAPS 1, 2, 4

Landing: FLAPS 5, FULL

Question 9

Maximum Flap Speeds are:

Answer 9

FLAPS 1: 230 kts

FLAPS 2: 215 kts

FLAPS 3: 200 kts

FLAPS 4 or 5: 180 kts

FLAPS FULL: 165 kts

Question 10

Speed brakes are ____ activated and ____ actuated.

Answer 10

Electronically / Hydraulically

Question 11

What is the difference between Ground Spoilers and Multifunction Spoilers?

Answer 11

Ground Spoilers: Inboard 2 panels that are dedicated ground spoilers (dump lift on landing)

Multifunction Spoilers: Outboard 3 panels that bleed energy (speed brakes), assist in roll control, and are ground spoilers.

Question 12

Under what three scenarios will the speed brakes automatically retract in flight?

Answer 12

Airspeed slower than 180 kts

Thrust near TOGA (70 deg TLA)

FLAPS 2 or greater

Question 13

What are the “functions” of the multifunction spoilers?

Answer 13

Bleed Energy (Speed Brakes)

Assist in Roll Control

Ground Spoilers

Question 14

All pilot commands are limited to ____ seconds before the trim cuts out.

Answer 14

3 seconds

Question 15

What does pressing SYS 1 CUTOUT and SYS 2 CUTOUT buttons do?

Answer 15

Disables HS-ACE (Horizontal Stabilizer-Actuator Control Electronics) Channel 1 (SYS 1) or Channel 2 (SYS 2)