The latest video from Flugsnug.com, Shall we land, shall we not, shows up perfectly what is called ground effect.
Put simply ground effect is the increased lift and decreased drag that the wings produce when close to the ground.
Pilots will often struggle with an aircraft floating.
Of course low-winged aircraft are more affected by ground effect than high-wing aircraft.
This video captures perfectly the impact of ground effect, particularly on the first plane the Grumman Gulfstream.