The Perils of
Wind Gradient
Like stepping into a hole
IT HAD BEEN A wonderful flight, and I was savoring the last mile or
two as I descended to the home field. There was enough wind out of
the northeast to compel a landing on the northeast runway, so
I checked for traffic, did my usual Quicksilver GT400
pre-landing checklist, and set up an approach—a
pretty decent approach, it seemed, until I dropped
it in from about four feet up.
I had not felt or seen any loss of airspeed in the
moment before the airplane fell. In fact, the ground
was clearly going past at its usual clip, everything
looked and felt normal, and I’d lulled myself into
thinking that the landing was pretty much
done; at just that moment the airplane ran out
of lift and began to drop. I ran the throttle
forward to soften my contact with the ground
and pulled the yoke back to ensure that the
mains, and not the nose wheel, took the brunt
of the hit. Maybe these actions helped
slightly, but like the doofy-looking bird in my
drawing, it was as if I’d stepped off a curb to
discover that there was an open manhole
located in just the wrong place. The airplane
struck hard, bending the right main-gear leg.
OF KITES AND SAILING SHIPS
The cause was wind gradient. That’s the term
(in case you weren’t listening during flight
training) for the fact that wind flows more
slowly near the ground than it does higher up.
The difference can be significant, especially
72 Sport Aviation May 2010
