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(c) directional stability:
(i) large fore/aft displacement of the CG
(ii) large versus small fin and rudder moment
2.6.2 Describe the relationship between directional and lateral stability (spiral instability)
and state the effect of spiral instability on the control of an aeroplane
2.6.3 Recognise statements/diagrams which describe static and dynamic stability
2.6.4 Describe the controllability problems associated with flight in the region of reverse
command
2.6.5 Explain the purpose of the following:
(a) trim tabs (fixed and cockpit controlled)
(b) balance tabs
(c) anti-balance tabs
(d) aerodynamic balance
(e) mass balance.
2.6.6 Explain the function of the items mentioned in 2.6.5 in relation to the movement of a
main control surface.
2.7
Taxi, take-off and landing
2.7.1 Describe the stability and control characteristics of nose wheel aeroplanes during
ground operation
2.7.2 Describe the result of the following factors on the controllability of an aeroplane:
(a) propeller torque and slipstream effect
(b) gyroscopic effect
(c) asymmetric blade effect
2.7.3 Describe the term “ground effect” and its effect on aeroplane performance.
2.8
Stalling, spinning and spiral dives
2.8.1 Describe the following:
(a) the symptoms when approaching the stall
(b) the characteristics of a stall
2.8.2 Explain the following:
(a) the effect of using ailerons when approaching and during the stall
(b) why an aeroplane may stall at different speeds
2.8.3 List the effect (increase/decrease/nil) of the following variables on the level flight stall
IAS:
(a) power
(b) flap
(c) wind shear vertical gusts
(d) manoeuvres
(e) weight
(f) frost and ice
(g) altitude
2.8.4 Describe the aerodynamic principles of stall recovery.
2.8.5 Describe manoeuvres during which an aeroplane may stall at an angle which appears
to be different to the true stalling angle
2.8.6 Differentiate between a spin and a spiral dive in a light aeroplane and describe the
standard recovery technique for each manoeuvre.