Nobody has yet mentioned the optical illusion of the 'apparent slip' and the 'apparent skid' when turning from
(a) Upwind to downwind, and
(b) Downwind to upwind,
at LOW level.
Turning from downwind to upwind, for example, the aircraft is 'carried' by the wind in the sideways direction during the turn (Drift), in the direction of the wind, so the track made good (TMG) over the ground is elongated in the direction of the wind, downstream.
The illusion to the pilot looking out of the window at his intended landing area, is therefore that the aircraft is 'skidding' out of the turn, in relation to the ground.
The "obvious" 'cure' is to tighten the turn.... Not good.
The real 'cure' is to keep checking the Turn and Balance (Bat & Ball) and to keep that ball in the centre whilst continuing the balanced turn, at a given angle of bank.
If its still going 'pear shaped' into getting where you wanted to position the aircraft, then a 'go around' is the best cure and start again, taking the wind into full account next time.
The 'illusion' is the fatal flaw, ask any 'croppie'.
(Not intended to 'preach', but simply to explain to some here, the physics v the illusion v the 'various airspeed arguments'.
The airspeed (IAS) remains constant by the way, for a given rate of turn in a given wind, at a given altitude, gusts and wind shear / inertia excluded.....Groundspeed (GS) should never be confused with airspeed (IAS).
Last edited by Ex FSO GRIFFO; 29th Jan 2017 at 01:24.