Ch 13 - Stalling Flashcards
Low Speed Stall
Caused by excessive AoA
- Boundary layer separates earlier as it no longer has the energy to stay on as the adverse pressure gradient is high
- Lift can no longer keep up with demand = Lift collapse
TO recover, reduce AoA
The Effective Airflow
The Aerofoil only cares about the Effective AoA
Rectangular Wing Stalling Characteristics
Elliptical Lift distribution
Increased vortices at the tips
CL highest at the root
Roots stall first as they reach the critical AoA first
They provide stall warning felt as light/heavy buffet
No violent wing drop
Elliptical Wing Stall Characteristics
Decreased wing tip vortices
Trailing edge vortices are consistent
Whole wing will stall together
Potential violent wing drop
Moderately Tapered Straight Edge wing stall characteristics
Wing is efficient
Stalls in the middle of the wing first
Can be violent
Swept Wing and highly tapered wing stall characteristics
Tips work harder than root
No stall warning
Bad wing drop
CofP moves Fwd -> Pitch up -> increased downforce from HS ->more pitching up ->unstable aircraft
Deep Stall (Locked in Stall)
Horizontal stabiliser will no longer produce downwash to pitch the nose down
- Stick pusher will kick in and force aircraft nose down or to limit it rising too far
- Airbus wont allow you to get to that point