Re: Steep turns on takeoff and landing

From:         Andy Tompson <andy@lll-winken.llnl.gov>
Organization: Lawrence Livermore National Laboratory
Date:         22 Jun 95 03:07:40 
References:   1
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Christopher Stone <cbstone@flagstaff.Princeton.EDU> wrote:
>
>Yesterday I landed on a TWA 727-200 at Albuquerque.  As we approached the
>airport, we made a steep turn to the right, then the left, then the right
>again.  Each turn was *very* steep -- it felt like we were tilting at
>about 45%, although I'm sure it must have been less than that.  During
>the final turn, the nose was pointing rather sharply towards the group,
>and we weren't that high up -- I could make the ground out quite clearly
>out of the window, and it didn't look like the wing was that far from the
>ground.

My guess is you were coming in form the north and made a big right turn to come
into runway 26 (or whatever the westbound main runway is there), and the first
right turn was too sharp to get lined up properly. This kind of turn is
required because of the Sandia hills off to the east, and it is a standard
approach there. The nose was pointing down because you were on final approach,
and it may have been required for getting in a lot of quick decent and for
angle-of-attack purposes (i.e., so as not to stall in the turn). I think (and
others may correct me about real operational capabilities) that these turns are
certainly within the operational envelope of the airplane, but are not used
that frequently so as to not alarm passengers.
>
>Usually I love flying, but I must admit that steep turns near the ground
>-- right after takeoff, or before landing -- always make me a tad
>nervous.  Is this merely an irrational fear on my part?  What are the
>limits upon how steeply an aircraft such as a B-727 can turn?  Is it any
>more dangerous to turn near the ground than high up?  Do pilots ever get
>dioriented as a result of this sort of turning?

Again, others may be able to cite the operational statistics. Irrational? Well,
you feel the way you feel, but I don;t think these kinds of turns are that
uncommon. I think it is always safer higher up because there is room to
compensate for uncertainties, either because of an inadvertant stall in the
kind of approach you describe, a stall in a straight-in approach (no turn),
wind shear for thunderstorms, etc. A friend of mine departed Las Vegas a year
or so ago on a 737, which had to return to the airport because of an engine
problem. One engine was shut down (I think it was the right one), and they were
coming back by looping around to the left to the same runway they departed on.
This was a little tricky because the pilot had to compensate for the lack of an
engine on the outside part of the turn (I recall that in single engine
situations, the operating engine should be on the outside parts of approach
turns, but I'm not sure). Anyway, in the left bank approach, there was a stall
which forced the captain to step on it, gain altitude, and go around again. But
it all worked out fine. I don't think the pilot had the spins, either.


>

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   Andrew F. B. Tompson                         (510) 422-6348
   Earth Sciences Division, L-206               (510) 422-3118 FAX
   Lawrence Livermore National Laboratory       afbt@llnl.gov
   P.O. Box 808, Livermore, CA 94551            andy@s50.es.llnl.gov
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