A downwind take-off into higher terrain is a bad thing.
There are no hard and fast rules. With a landing on a
one-way runway or with a tailwind, there will be a point at
which a go-around can be made safely and once you are below
that point, a landing is your only option. That's why
mountain and hill flying is a challenge



"Tony Cox" wrote in message
ups.com...
| Here's a problem which seems to have a non-trivial
solution.
| At least, I've not been able to find a definitive answer
to it, but
| what do I know??
|
| Suppose one wishes to land at an airport with a runway
| that slopes at X degrees. The wind -- assumed to be
directly
| aligned with the runway -- is Y knots from the "high" end
of
| the runway.
|
| Clearly, if Y is positive, one should try to land in the
| "up-slope" direction to minimize one's ground roll. One
| will be landing "up" and into a headwind. But what if
| Y is negative? Clearly, if Y is just a few knots neg, one
would
| still land "up-slope", because the braking effect of
rolling
| out up-hill more than compensates for the higher landing
| speed due to the tail wind.
|
| If Y is negative and more substantial, which way should
| one land? At some point, it makes sense to switch to the
| other end of the runway -- landing downhill -- to take
advantage
| of the (now) headwind. But how does one establish which
way
| to land, assuming no clues from other traffic in the
pattern? The
| aim is to select a direction, given X and Y, which would
result
| in the smaller ground roll.
|
| Rule of thumb responses are interesting, but better would
be
| a full mathematical treatment. Presumably, a proper
treatment
| would need to include touch-down speed too, and perhaps
| gross weight as well.
|
| Its more than an academic question for me. My home airport
| has a 3 degree runway, and some local airports are even
| steeper.
|