Susan,

This has to do with something called 'ground effect.' Can't get to my flight manuals/books right now, but this Wiki explanation is pretty good. He was doing the right thing at that time.

"As it pertains to fixed wing aircraft, "ground effect" refers to the increased lift and decreased drag that an aircraft airfoil or wing generates when an aircraft is about 1 wingspans length or less over the ground (or surface). This often gives light aircraft the feeling that they are "floating", especially when landing.

When an aircraft is flying at an altitude that is approximately at or below the same distance as the aircraft's wingspan there is, depending on airfoil and aircraft design, an often noticeable ground effect. This is caused primarily by the ground interrupting the wingtip vortices and downwash behind the wing. When a wing is flown very close to the ground, wingtip vortices are unable to form effectively due to the obstruction of the ground. The result is lower induced drag, which increases the speed and lift of the aircraft while it is in the ground effect.

A wing generates lift, in part, due to the difference in air pressure gradients on the wing surfaces: both upper and lower. During normal flight, the upper wing surface experiences reduced static air pressure and the lower surface comparatively higher static pressure, these air pressure differences also accelerate the mass of air downwards. Flying close to a surface increases air pressure on the lower wing surface, (the ram or cushion effect) improving the aircraft lift to drag ratio. As the wing gets lower the ground effect becomes more pronounced. While in the ground effect, the wing will require a lower angle of attack to produce the same amount of lift. If the angle of attack and velocity remain constant, an increase in the lift coefficient will result, accounting for the "floating" effect. Ground effect will also alter thrust versus velocity in that reducing induced drag will require less thrust to maintain velocity.

Low winged aircraft are more affected by ground effect than high wing aircraft. Due to the change in up-wash, down-wash and wingtip vortices there may be errors in the airspeed system while in ground effect due to changes in the local pressure at the static source."