Chapter 18: Controls

Question 1

Control Column

Good Design Criteria (4)

Answer 1

Adequate force
Responsive
Adequate control column displacement
Harmonization pitch, roll

Question 2

Aerodynamic Balances (7)
Info

Answer 2

Inset Hinge - hinge close to CP (25% max)
Horned Balance
Internal Balance
Balance Tab
Imbalance Tab - makes controls harder
Servo Tab - moves tab, bad at low speeds
Spring - low V moves surface, high V moves tab

Question 3

Flutter Improvement

Answer 3

Mass forward of hinge

Question 4

Controls Type

Fully Powered vs. Power Assisted? How is Fully Powered Complemented?

Answer 4

Fully Powered: servo valve allows hydraulic P to move surface. No power, no input
Power Assisted: hydraulic P moves surfaces, pilot has natural feel
Q-feel: artificial force feedback prop. q

Question 5

Aerodynamic Damping

Answer 5

Roll -> wing going down sees higher AoA -> goes up -> resists roll

Question 6

All Moving Tailplane vs Classical Tailplane

Answer 6

All moving: changes AoA

Classical: changes camber

Question 7

Trim Horizontal Stabiliser

Other Name, Advantages (4)

Answer 7

Variable Incidence Tailplane:
Aerodynamic
Great CG range
No control authority loss
Flutter resistent

Question 8

Aerodynamic Balances

Disadvantages (2)

Answer 8

Loss control authority
Drag
Forward / Aft CG issues
Flutter

Question 9

T Tail Design

Advantages (2)

Answer 9

No downwash (flaps, wings ...)
No ground effect

Question 10

Rudder Stall

When is it bad? Solution?

Answer 10

OEI
Crosswind landing

Sweepback Rudder -> AoAs increases

Question 11

Rudder Travel Limit

Answer 11

Low V -> full deflection

High V -> low deflection

Question 12

Adverse Aileron Yaw

Answer 12

Wing going up -> Cl+, Cd+

Yaw around up wing

Question 13

Adverse Aileron Yaw Solutions (4)

Info

Answer 13

Frize Ailerons: up aileron creates more drag
Differential Ailerons: up aileron higher deflection
Spoiler: Compensates for D, less prone to flutter
Control coupling: automatic rudder