Frans, Certainly the nose will be further down with flaps than without but
either way it is still up as long as the plane is flying, and being able to
see a bit more over the nose and being in the landing attitude that you are
used to landing the plane with seem to me to be significant advantages,
quite apart from hitting the water at an appreciably lower speed ( and of
course the energy of impact varies with the square of the speed. so for my
plane 49x49 = 2401 vs 39x39=1521, so barely 60% of the energy with flaps
down. If you were flying into a 10kt wind the difference would be closer to
half) Unless you are landing on a dead still inland lake I suspect that the
landing will be a major fairly abrupt splosh rather than a skidding along
the surface and lower energy will be very beneficial.
Regards, David Joyce, G-XSDJ
----- Original Message -----
From: "Frans Veldman" <frans@privatepilots.nl>
Sent: Tuesday, May 04, 2010 1:56 PM
Subject: Re: Europa-List: Ditching checklist
>
> 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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