FROG SWALE REVISITED

You might fly hundreds of launches without needing to abort for some atmospheric reason, but have no doubt, eventually it will happen. One condition that multiplies the probability is a strong direct crosswind. Aside from the usual problems of ordinary quartering crosswinds, a ninety-degree cross raises the possibility of sudden tailwind component, and that’s not all. Enter a specter normally associated only with landing, the slowing of wind near the surface, called wind gradient. In this case it’s the increase in wind with height that becomes a problem.
Say you begin with a crosswind near the limit, fifteen knots or more depending on many variables. Halfway up the strip both aircraft have lifted off when, about twenty feet high the wind abruptly doubles. If the tow pilot responds properly your crab angle also may double, which is okay so long as you swing out downwind to stay in good tow position. Trouble comes when that stronger wind blows both birds sideways, off the runway and low over ground that may not be entirely clear. If the increase in ambient wind is 10 knots, five seconds later you’re a couple wingspans from the centerline! This can wake you right up. It happened to me once long ago in jolly old New England, then again here at Crystal, and then became part of my usual spiel for Flight Reviews.
In the first mindbender we were swept sideways over deep grass rolling downhill into a swale. As good a place as any for a crash landing except for the pesky cattle fence and a clan of darling frogs. Beyond that fence and lower than the runway is where the tug’s wheels started nicking brush. Expecting to be cut loose, I reached to release, thinking better to crash without the tug than into it. Exactly then we started pulling away from the ground, and climbed on up normally, as if…
But that’s not the point. Stack of bubbles, this very thing occurred again in the exact same place with someone else not long after.
The second time it happened to me was here at Crystal, where we have no handy swale. I could have aborted even as we skimmed over the fuel truck, but every moment of indecision made that less feasible. If a double-wide mobile home had not been recently removed, into it is where we might have crashed. On we drifted in ground effect, sidewise across the entrance road and past the hangers — on the wrong side! By then it was too late to do anything but hang in and pray we hit no sink.
Getting away with such a thing doesn’t mean we deserved to. What I should have done in each case was RELEASE IMMEDIATELY and land while we still had half the airport right there ahead, upwind of us.
Nutshell: with direct crosswinds be more than ever ready to abort NOW and get safely back on the ground while you still can. Otherwise… here at Crystal we have only Joshuas, not frogs to cushion your impact.
Soaring Is Learning