Text 38666, 53 rader
Skriven 2006-09-08 14:05:21 av Ward Dossche (2:292/854)
     Kommentar till en text av Michiel van der Vlist
Ärende: Re: Bic lighter?                        was: Frank - take a break (was
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Michiel,
 
> WD> That mountain indeed is an issue as with reduced engine power the
> WD> plane will still clime-out but smack into the mountain.
 
> One thing that puzzles me: The mountain is only a problem when using
> runway 09. Runway 27 ends on open sea, so no problem there. But isn't the
> CaribBean one of those places where the wind always blows west? So runway
> 27 would be the one to use? What am I missing?
 
At SXM the wind nearly always blows, and it blows west. Most of the time at a
speed over 15 knots.
 
Every airplane is certified for a maximum tailwind operation and I know none
that exceeds 15 knots. The B747 has 15, most others are lower.
 
Landing or taking-off with tailwind requires you more runway for either braking
or accelerating and at SXM with a tailwind in excess of 15 knots when
taking-off from rwy27 (towards that funny beach in other words) the average
plane would get to the end of the runway before reaching Vr (the speed of
rotation) and hence crash off the runway straight into the sea ...
theoretically even a Cessna-150 or a PiperCub.
 
Another thing to contemplate is that taking-off with a tailwind requires higher
speeds, and airplane-tyres are certified up to certain speeds. So it may very
well be that at a certain moment there is enough runway length to take-off but
the plane would need such a speed that tyres would burst.
 
Have I made some sense?
 
Sometimes there are take-offs at SXM on 27 but these are rare.
 
There's the story of this American DC10 pilot who tankered 40.000 lbs of fuel
up to maximum-limits of the plane assuming he would be using 27 ("tankering"
means taking more fuel on board than you need, often done in places where it is
cheaper or with restrictions on the export of money) as winds had dropped away.
 
Then winds suddenly started again.
 
There was no way he would be able to get off the runway at 09 and over the
mountain, even without engine failure. The was also no way to de-fuel the
plane. So they had to unload 100 passengers and their bags, fly to San Juan in
Porto Rico, unload what he had, go back empty to SXM, load the 100 passengers
and their bags, fly to Porto Rico, pick-up the passengers left behind, then fly
to New York.
 
Instead of getting his company a good fuel duel, he eventually cost them a lot.
I don't know if anything happened to him afterwards.
 
 \%/@rd

--- D'Bridge 2.55
 * Origin: "Leonard will be free" - http://www.leonardpeltier.org (2:292/854)