Obstacle generated ’Curl Over’

What happens to the smooth flowing air as it passes over obstacles on the ground. Hedges, buildings and woodland for example, can produce a turbulence at different heights above the ground. This is often felt by light aircraft particularly. It is common for example to feel an effect on the aeroplanes flight characteristics at heights of about 1000 feet. This is not a worry! In fact it demonstrates the density of the air around us and is why flight is possible at all. It is this dynamic quality demonstrated by turbulence that is essential for gliders to stay aloft for example. It is near the ground that the effect deserves greater attention. Especially where hedgerows or ground hugging obstacles affect the air that flows across a runway for example. The unwary pilot can be caught out by the curl over produced on the lee side of these obstacles. The danger is that the aircraft can lose height very quickly in the final stages of a landing. This simulation helps us to visualise the invisible and reveals how ai