On Wed, 23 Sep 2009 01:45:02 +0000, Nyal Williams wrote:

I've heard pilots say that the departure of an aircraft will kick off a
thermal from the runway. Worth watching if you are relatively low over
the field and your timing is right to search it out.

Its well known in the free flight model flying world that in the right
conditions a few people running about flapping T-shirts can kick off a
thermal. I once made my own thermal just by running about circle towing
an F1A class competition glider in sparse foot-high dry grass on calm
early morning conditions. It wasn't strong though - just enough to make a
model with a 0.3 m/s min sink speed climb slowly.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |