Sport Pilot Talk

Isabella County, Michigan. No fatalities, but the airplane is written off. The left wing clipped a tree taking off.

https://aviation-safety.net/wikibase/227677

Mt. Pleasant, Michigan.

That looked like rougher water than I'd take off from in a seaplane - and it seemed to take them an inordinate amount of time get airborne.

I’m not a sea plane rated pilot, nor do I play one on TV, that said, I can tell you from watching that video, the flight was doomed from the start. Thanks for posting Stan and thank god no one was seriously hurt. Very, very lucky...

It’s hard to tell in the video if the takeoff run was into the wind.

It also looks like a lot of flaps, but not sure what the takeoff setting is in an A5.

Seems like just another 5 or 10 seconds in “ground” effect to build speed would have avoided this accident entirely, regardless of what preceded it.

Looking at the waves early in the video and the sailboat off in the distance during his takeoff run, I think he took off into the wind, but took much longer that anticipated due to the rough water. Once airborne, he had to make a turn to the right to avoid the trees. Just as he was leaving ground effect, he turned downwind and lost a lot of lift (ground speed does not increase instantaneously). He started mushing down and then clipped a tree.

It looked to me he had a lot of water behind him when he started his takeoff run.

TimTaylor wrote:It looked to me he had a lot of water behind him when he started his takeoff run.

True, but perhaps unavoidable. According to news reports, there were a lot of boats on the lake at the time of the accident. Perhaps he had to water-taxi out of the way to avoid them.

Looks to me like the fact that he clipped the tree was a blessing in disguise - he was already stalled before that and started dropping his right wing - hitting the tree actually dissipated some of that energy and let him smash the water at quite a bit lower velocity.

TimTaylor wrote:Just as he was leaving ground effect, he turned downwind and lost a lot of lift (ground speed does not increase instantaneously).

Once airborne, the plane is simply flying in a parcel of air which is itself moving. Turning “downwind” is no different from turning “upwind” as far as lift goes.

This is also being hashed out over on the Pilots of America site. As usual, gusts and shear are creeping into the discussion. While they may have an effect on the plane, neither has anything to do with whether the plane is turning upwind or downwind.

As I said, the plane does not instantaneously increase in ground speed as you turn downwind. If you had a 15 knot headwind followed by a 15 knot tailwind, the plane doesn't instantly gain 30 knots groundspeed, but we may disagree on this.

Ground speed doesn’t matter. The plane has no “connection” to the ground once in the air. It’s no longer the frame of reference, the air mass is. And the direction of the movement of the airmass over the ground makes no difference to the plane’s aerodynamic performance, including tendency to stall.

Ground speed doesn't matter except as an indication of relative wind. The plane has a certain momentum to overcome. You don't agree so enough said.

A 15 knot loss of airspeed (as in a, non-microburst, wind shear event) would definitely impact the performance of the airplane. Once the shear event occurs (energy loss), there is a lag in the response time, for the aircraft to recover/overcome that loss in performance.

Wm.Ince wrote:A 15 knot loss of airspeed (as in a, non-microburst, wind shear event)...

Of course. Stipulated.

But not relevant to a discussion about the effect of a downwind turn on lift and/or stall.

FastEddie, you are correct but have an over-simplified understanding of the situation. You are ignoring the effects of momentum (energy) of the aircraft that must be overcome, especially if the turn is quick. Why does your car try to go straight when you go around a curve at high speed?