Chapter 31: Limitations

Question 1

Limit Load
AC Types (3) and LL

Answer 1

Normal: 2.5g
Utility: 4.4g
Aerobatic: 6g

Question 2

Va

What is? How much faster to reach UL? UL = failure? How does mass affect Va

Answer 2

Max speed with full elevator deflection without structural damage (LL)
Meeting point of stall and LL
1.23% Va = UL
UL for max TO, therefore not necessarily destroys AC

Question 3

Va

What affects Va (3)

Answer 3

Lighter mass = decreases Va
High alt = Va increases
Flaps = Va decreases

Question 4

Vb

What is, where on n diagram

Answer 4

Can withstand max vertical gust

Between Va and Vc

Question 5

Vra/Mra

Answer 5

Turbulence penetration speed (ra = rough air)
fast enough to not stall
slow enough to avoid structural damage

Question 6

Vc/Mc

Vd/Md

Answer 6

C: Speed for severe turbulence
D: Max structural limit, is a function of Vc/Mc

Question 7

Limiting Velocities
Large AC (2), Small AC (2), gear (2), flaps (1)

Answer 7

Vmo: max operating (large AC)
Mmo: max operating (large AC)
Vne: never exceed (small AC)
Vno: operating cruise outside of turb (small AC)
Vle: gear extension
Vlo: gear operating
Vfe: flap extension

Question 8

Gust

Affects (5)

Answer 8

Altitude: higher TAS, less change in α
Airspeed: higher %increase in CL with high V
Cl/α function: high change Cl/α is bad (straight wing)
Wing Loading: low wing loading
High AR

Question 9

Flutter Resonance

What is, how affected (6)

Answer 9

Wing twist around torsional axis due to resonance
Elasticity, mass distribution, structural properties
backlash (too much slack), IAS, aero-elasticity coupling

Question 10

Danger with Outboard Ailerons at High speed

Answer 10

High speed aileron reversal
flutter -> aileron acts opposite way
outboard ailerons are locked at high speeds