Re: Question: Vertical speed on landing?

Date:         18 Mar 97 03:14:51 
From:         "Andre Neves" <andre.neves@individual.eunet.pt>
Organization: EUnet Portugal
References:   1 2 3 4
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RydellSCB <RydellSCB@prodigy.net> wrote in article
<airliners.1997.682@ohare.Chicago.COM>...

> As the FAR's show, the vertical decent rate limit is governed
> by max landing weight.  The 12 fps is taken as an ultimate (failure)
> condition, and 10fps is limit (i.e. yielding).  I don't know
> if gear is actually _tested_ to 12, I think only to 10.
> (I've seen the drop test videos - what an explosive event!)
> BTW, that rate applies to all jet transport airplanes.
>
> For any sort of a max takeoff weight landing
> situation, the airplane is already committed to flight and
> would dump fuel to get the weight down to landing weight
> before it tried to land again.  I don't
> think _any_ airplane could land at more than 7 or 8 fps (approx)
> at max takeoff.

All this seems strange to me as I believe that 500 fpm landings
are quite frequent specially in bad weather or with some "less skilled"
pilots and aircraft hold just fine (somebody told me an A340 could handle
2000 fpm prior to collapse! that's 33fps).
10 fps is only 600 fpm, it's not enormous!
The only explanation I can think of is that these figures grow fast with a
lighter than MLW ladden aircraft.