Principles of Flight Lesson 2 â€“ Stability and Control Stalling
Principles of Flight Stability and Control
3 aircraft axes
Why do we want stability?
Longitudinal Stability â€˘ Response to bumps â€˘ Response to aircraft not being trimmed correctly
Lateral Stability â€˘ Response to bumps that lift one wing only
Directional Stability â€˘ Response to side forces â€“ e.g crosswinds
Pilot Controls • Easiest way to show you is…..
How can we make it easier for the pilot? • Constantly having to adjust the controls is tiring • The balance of the plane is always changing due to the weather, weight changes and power settings • To make life easier for the pilots, the thoughtful designers add Trim Tabs
Other control surfaces â€˘ Flaps - revision
Flaps • Flaps can extend to different positions – 0, 30, 60, 90 typical
• Flaps greatly increase lift with not much drag penalty up to around 60° • From 60° to 90° the drag shoots up • To maintain speed, the pilot lowers the nose – giving a better view of the runway
Flaps and Slats working together
Principles of Flight Stalling
Stalling • What is a stall? • Why does a stall occur? • What affects the speed at which the stall occurs
What we learnt last week â€˘ Increase in AoA increase lift
What we learnt last week â€˘ Lift increase with AofA until it stalls
Things that affect the stall - weight
Things that affect the stall – ‘g’
Things that affect the stall â€“ angle of bank
This is what happens!
Things that affect the stall â€“ power
Things that affect the stall â€“ flaps
Things that affect the stall – other things! • Ice – build up changes the shape of the wing and can greatly increase the stall speed • Wing damage – damage can disrupt airflow and increase stalling speed