Ashling
and as Owain says as he enters ground effect his alpha will increase.
That is not at all what I am saying
As he enters ground effect the lift at a given alpha will increase and the drag at a given CL will decrease. This is not the same as saying that alpha will increase.
With regard to the effect of ground on stall, the maximum lift coefficient is hardly affected, but the AoA at which it is achieved is reduced, as is the stall AoA. This effect was mentioned by IIRC one of the Boeing lecturers at the recent RAeS conference on flight testing of stalls, but the relevant graph was not dimensioned.