On 05/04/2010 12:52 PM, David Joyce wrote:
> Frans, I like the single person life raft, although if flying with a
> passenger it would be psychologically good to be in the same boat as
> your mate.
I agree. But the best thing is being able to get the raft out, inflate
it before loosing it, and make sure the drift rate of the raft is lower
than the swim capabilities of the fully dressed passenger or pilot. ;-)
> Having flown a lot over water I have given the matter of
> ditching a fair bit of thought. With my mono my plan is to have max flap
> + wheel down to give minimum approach speed (water being awfully hard at
> speed) but I would leave the gear unlocked so that the wheel hitting the
> water would retract itself (I guess), and limit the tendency to trip
> over the wheel and bury the nose.
Yes, that could work I guess. The only flaw I see is that extending the
flaps lowers the nose somewhat, and with ditching you want to keep the
nose as long as possible out of the water, to prevent it from digging
in. And I have some doubts what will happen first; the wheel retracting
or the wheel dragging the nose down. Taking inertia in mind these things
may happen simultaneously. As I have a tri gear, this question is a
hypothetical one. I plan to get the main gear touching first, and bleed
off as much speed as possible before the rest of the plane makes contact
with the water. Big question of course is whether the gear will stand
the forces or gets ripped off immediately...
About the flaps: what I have read (on the same site you recommended) is
that a few things will happen if you extent the flaps:
1) The flaps will change the attitude of the Europa to a more nose down
position. This is what you want to avoid when ditching. The more you can
keep the nose up, the better chance you have.
2) With the low wing Europa's, the flaps are among the first things to
contact the water. As the flaps are behind the wing spar, they will
rotate the plan nose up/tail down upon contact with the water. This
might cause the airplane to dig in violently as soon as the flaps touch
the water.
3) Given the forces involved, the flaps might depart the airplane upon
contact with the water. If they both depart simultaneously, it might be
not such a problem, but if one departs before the other, it leaves you
with a very asymmetrical setup during the flare, probably leaving the
airplane out of control. The remaining flap will turn the airplane
sideways, not a good thing!
So, I plan not to use the flaps, or with a compromise of about 10 degrees.
The trade off of course is that with less flaps the approach speed is
somewhat faster.
Let's hope that we will never find out which approach is the best one!
Frans
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