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Principles of Flight Lesson 2 – Stability and Control Stalling

Principles of Flight Stability and Control

3 aircraft axes

Why do we want stability?

Longitudinal Stability • Response to bumps • Response to aircraft not being trimmed correctly

Lateral Stability • Response to bumps that lift one wing only

Lateral Stability

Lateral Stability

Directional Stability • Response to side forces – 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

Trim Tabs

Trim Tabs

Other control surfaces • 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 • Increase in AoA increase lift

What we learnt last week • Lift increase with AofA until it stalls

Things that affect the stall - weight

Things that affect the stall – ‘g’

Things that affect the stall – angle of bank

This is what happens!

Things that affect the stall – power

Things that affect the stall – 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

Principles of flight lesson 2  

Stability and control, stalling