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Hi Philip...My wife asked you for you advice on landing a DA40 a few
days ago, and your reply was very helpful. But the real issue is
this: I was landing my plane about two weeks ago when an unexpected
wind gust caught me. Just as I was about to touch down, the plane
ballooned up about 30 feet. It seemed to me that this was a
tailwind, because my ground speed seemed to increase. I don't
remember if I had touched down or not before the ballooning. I tried
to cushion the impact from this ballooning by lowering the nose ( I
was fairly nose-up pitched at the height of the ballooning) and tried
to fly the plane onto the runway. After this first ballooning, the
plane bounced pretty hard and high off the runway surface, and I felt
as though the plane was going to start porposing. There were two or
three more bounces after these first two. The result is that I got a
prop strike. I guess the essential questions I want to ask are these
1 - when the plane balloons up for any reason ( such as flairing to
much too quickly), is the best thing to do is to keep the nose up
even if it results in a hard (but nose-up) landing rather than trying
to fly the plane onto the runway? 2 - Going around during this
attempted landing did not seem feasible in retrospect, probably
because it seemed as I was landing that I had too much ground speed
and had used up too much runway. Also, the first ballooning
surprised me so much by the height of the plane above the runway
surface that I was suddenly preoccupied with getting the plane down
safely. The runway at this airport is 2500 feet, and there is a hill
at the departure end making good climb performance mandatory. As I
was landing I of course had landing flaps. My question is this: Can
the DA40 take off and climb from flairing airspeed (say 60 knots)
with full flaps in about as much distance as taking off with take-off
flaps? In other words, if I had tried a go-around, would I have been
able to gain as much altitude starting with an airspeed of 60 knots
and full flaps as I can during a normal take-off? I keep kicking
myself for not doing a go-around, but even in retrospect, I'm not
sure I could have done it given runway behind me and full flaps in.
Also, I did not know I had a prop strike until I shut the engine
down, and if the strike occurred during the first bounce, I never
could have climbed out because of the damage to the prop. Any advice
you can give on the best way to save a botched landing (including
when to go around and when not to) would be greatly appreciated. --
-- John Swanson, May 5, 2006
Ouch. First of all, you can check out the climb performance with full flaps as soon as you've got your airplane back up and running. It is remarkably good, actually. A DA40 is not like an older Cessna in having flaps that are so dramatic that climbing becomes impossible. I think you can certainly get 500 fpm at gross weight with full flaps and full power.
On the "what to do after a bounce", Brad (below) is right in that a go-around is the best procedure. At my home airport, Hanscom, which has a 7000' runway and a busy pattern, I have often been tempted to cheat with students and if they end up flaring too high, it does work to add a few inches of manifold pressure, push the nose forward a touch, and salvage the landing. We do get down reasonably smoothly in the end, but it uses up 4000' of runway and sets a bad example. (The same technique works after a bounce; you're in a high attitude and several feet off the runway; more power and a lower attitude (higher airspeed) will reduce the sink rate and result in a smoother impact.)
In gusty conditions, I think it is essential to plan for a go-around on every approach, as Brad says. In a light slow plane such as the DA40, a big wind gust can destabilize the roundout and flare enough that landing smoothly becomes uncertain.
One thing that might help is flying, with an instructor, very low over a 12,000' military runway in your neighborhood. Touch the mains down every now, keep an eye on the attitude that the plane has at various reasonable airspeeds and vertical descent rates. Also try some approaches and landings with the airspeed indicator covered up. The DA40 will use more runway if you don't nail the airspeed, but if you get the attitudes right, every landing will be reasonably smooth.
John: As an aside, I think you may need to learn to spell "porpoising" if you're going to be chewing over this incident :-)
-- Philip Greenspun, May 9, 2006
Anytime is a good time to go-around. If the thought ever crosses your mind during a landing or approach, go-around and figure out why you had that incling while you are far away from the ground. In the airline environment anybody in the cockpit can call a go-around and it will be done immediately and questions asked later.
I think that sometimes people feel executing a go-around is an admission of defeat or sub-par performance. That cannot be more untrue. As you are rolling down the runway for takeoff, with your hand on the throttle, you should be thinking to yourself "abort, abort, abort, abort" until the airplane is flying or you are past a point of no-return. The same on approach and landing. Set-up some stablized approach criteria for yourself from 2000' AGL - sfc. and be thinking "go-around, go-around" until the airplane is safely stopped off the runway. Of course don't let the prospect of a go-around preculde good thinking on the landing.
-- Bradrick Pretzer, May 6, 2006