Planning a flight

Well, excuuuuuuuuuuuuse meeeee.


On Wed, 23 Feb 2005 19:57:05 -0000, "Chris"
wrote:

Can you guys continue this discussion in another thread and leave this one
to deal with the original post.

Chris
wrote in message
.. .
On Wed, 23 Feb 2005 18:23:35 GMT, Jose
wrote:


Yes. I was addressing flight planning, and your contention that the
area of no (good) options is independent of winds. I claim that the
area location =is= dependent on winds, and the area's size in minutes is
also dependent on winds. The first is useful for flight planning (draw
a line on the chart) and the second is useful for a go/no-go decision.
One might be comfortable with a fifteen minute no-option time, but not
with a forty-five minute no-option time


The area in square miles that is available to you to glide to at any
given moment is independent of winds. It is an inverted cone around
your aircraft. The geographic center of this cone will be downwind of
the aircraft, but its area does not change. You can glide to the edge
of that cone, period. You can get farther in one direction (downwind)
than another, but that's merely a tradeoff, and you might not
necessarily strive for the furthest possible point (especially if it's
under water.)

The cone will move faster,as the aircraft moves faster over the
ground, so the cone will be completely surrounded by water (the "no
good option" time) for a shorter period, the greater the
groundspeed..

I don't know what you mean when you say the "area's size in minutes
is dependent on winds". One can only alter the distance one can
glide by using winds, by gliding in one direction or another. One
cannot alter the size of the area. What one gains in one direction,
he gives up in the other.

Chris wrote:
Can you guys continue this discussion in another thread and leave this one
to deal with the original post.

Well, hey, this is usenet after all, plus I thought your questions had been
pretty well addressed, as usenet questions/answers go.

But OK, I can answer one of your original questions. I have flown across L.
Michigan several times going and coming from Oshkosh, in a PA28-180 and a M20J.

You're going to find some people who say it's no problem, and some people who
say they'd never do such a foolish thing. Everybody has their own limits to the
amount of risk they're willing to assume.

Sorry, I can't answer any of your other questions.

Now addressing the drifted thread...

wrote:

snip

The cone will move faster,as the aircraft moves faster over the
ground, so the cone will be completely surrounded by water (the "no
good option" time) for a shorter period, the greater the
groundspeed..

I don't know what you mean when you say the "area's size in minutes
is dependent on winds". One can only alter the distance one can
glide by using winds, by gliding in one direction or another. One
cannot alter the size of the area. What one gains in one direction,
he gives up in the other.

cfeyeeye, what teacherjh means is exactly what you said in the first paragraph I
quoted above. You are just talking past one another talking about different
areas. You are describing the size of the circle once the fan quits. Teacherjh
is describing the size of the no-good-option time.

wrote in message
...
On Wed, 23 Feb 2005 18:23:35 GMT, Jose
wrote:
The area in square miles that is available to you to glide to at any
given moment is independent of winds. It is an inverted cone around
your aircraft. The geographic center of this cone will be downwind of
the aircraft, but its area does not change. You can glide to the edge
of that cone, period. You can get farther in one direction (downwind)
than another, but that's merely a tradeoff, and you might not
necessarily strive for the furthest possible point (especially if it's
under water.)

...One can only alter the distance one can
glide by using winds, by gliding in one direction or another. One
cannot alter the size of the area. What one gains in one direction,
he gives up in the other.

You're presuming the same glide speed in all cases, aren't you? But in the
presence of wind, you can increase the glide area by diving faster than
best-glide speed if you're heading upwind, and slowing toward best-endurance
speed if you're heading downwind. (In the absence of wind, flying faster or
slower than best-glide speed can only decrease the glide area.)

Also, it's worth mentioning that the foregoing all assumes level terrain.
The presence of wind can change the available glide area--even for a fixed
glide speed--if the terrain is uneven (though that's obviously inapplicable
to a lake).

--Gary

On Wed, 23 Feb 2005 15:34:21 -0500, "Gary Drescher"
wrote:

You're presuming the same glide speed in all cases, aren't you? But in the
presence of wind, you can increase the glide area by diving faster than
best-glide speed if you're heading upwind, and slowing toward best-endurance
speed if you're heading downwind. (In the absence of wind, flying faster or
slower than best-glide speed can only decrease the glide area.)


True enough, as any glider pilot knows.

But it seemed to unnecessarily complicate the issue, and mostly
irrelevant to what we were discussing.