Re: What operational measures avoid hydroplaning?


tscottme wrote:
<snip>

> Read a story about a 737 (classic) landing accident. Landing in heavey rain
> with a big crosswind on the older design 737, combined with "sub-optimal"
> crew techniqe the aircraft landed long and fast, on a short runway. The
> aircraft's weight-on-wheel switch only sensed one of the main gear, the one
> that happened to be touching down last. This delayed the automatic
> deployment of spoilers and activation of thrust reversers. All this coupled
> with faster approach speed to cope with "dynamic weather" contributed to the
> accident.
>
> One recomendation I remember when hydroplaning was possible was to make a
> "solid arrival" not a squeaker. Get the weight on the ground solidly to
> begin the braking sequence. In the above accident aircraft, the wheels
> seemed to land in a hydroplaning condition, the wheels didn't spin up, the
> autobraking or anti-skid system therefore didn't begin it's job promptly.
>
> --
<snip>

I'm sure i've seen something similar to above for a small airbus (320?)
overrun in heavy rain somewhere in europe.
>>From memory (not reliabale) it showed issues with the control software
as event went something like this : land, aquaplane, wheels don't spin
up, control logic needs wheel speed to confirm landing before deploying
spoilers, no spoliers and little retardation means wings still lifting
('float'?), therefore oleos still extended (no weight on wheels
signal), thrust reverse need weight on wheels signal to deploy, no
brakes and no rev thrust. By the time it settled it overran I think
into an earth bank.

Proberbly unrelated but interesting all the same.

Finally congrats to the cabin crew all off in under 5 mins, certainly
made me listen to the briefing on my flight last night.

.

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