021 AS PT3

Question 1

Wat is het verschil tussen resonance en flutter?

Answer 1

Flutter: uncontrolled oscillation that can occur on fixed surfaces
Resonance: vibration at a specific frequence that amplifies the flutter -> can lead to failure

Prevention: mass balancing & reducing play

Question 2

Wat is de ply rating?

Answer 2

Index of strenght for the tire (NOT THE NUMBER/AMOUNT OF PLIES)

Question 3

Wat zijn de limits voor creep?

Answer 3

1’ for <24cm

1,5’ for >24cm

Question 4

Wat is adverse yaw?

Answer 4

yawing in the opposite direction of the rolling moment due to more induced drag on the downgoing wing

Question 5

How to counteract adverse yaw? (3)

Answer 5

Differential ailerons
Frise Ailerons
Aileron-rudder coupling

Question 6

Wat zijn de advantages en disadvantes van FBW?

Answer 6

Advantages:
- Weight: less control cables, smaller stabilising surfaces
- Pilot work load reduced: autotrim, turn coordination
- Flight Envelope Protection: no pitching beyond the stalling AoA
Disavantages
- Reliability: a lot of redundancies need to be built in

Question 7

Wat zijn de drie pressurization controllers?

Answer 7

• Pneumatic controllers: metering valves for selecting the required cabin alt & rate of pressure change
• Outflow valves
• Ditching control

Question 8

Noem de 3 ice detectors

Answer 8

Rotary (napier): fixed knife-edge cutter (torque measured)
Rosemount: vibrating rod thatmeasures frequency drops
Sangamo Weston: detect moisture + temp difference sensing head

Question 9

Wat is het verschil tussen de-icing & anti-icing?

Answer 9

De-icing: als het ijs er al is, om het weg te halen

Anti-icing: voorkomen dat het ijs komt

Question 10

Wat is de sequence van discharging a fire bottle? (4)

Answer 10

1) Engine shutdown
2) Cartridge will be armed
3) Cartridge will be fired pressing on AGENT
4) Pressured extinguishant operates a electrical swich which illuminates DISCH caption on AGENT selectors

Question 11

Wat is het verschil tussen safe life / fail safe en damage tolerant?

Answer 11

Safe life: cycles, replaced after fixed amount of days, cycles, … -> known that no catatrophic damage would occur
Fail safe: redudancy, multiple load paths
Damage tolerant: OK until normal inspection, (eg by spreading load over larger area) certain amount of weaking without catastrophic failure

Question 12

Wat zijn de ideale eigenschappen van een hydraulic fluid?

Answer 12

Incompressible, low viscosity, low freezing point high flash point, non-flammable, themal stability, non- corrosive, lubricating properties

Question 13

Wat is het verschil tussen een reservoir en een accumulator?

Answer 13

Reservoir: only storage
Accumulator: story energy, fluid onder pressure -> damp fluctuations, emergency supply