wrote:

On Sun, 24 Apr 2005 18:20:41 -0700, wrote:



wrote:

On Sun, 24 Apr 2005 19:05:36 GMT, Greg Esres
wrote:

What sort of climb gradient you end up with is due to chance.

Maybe in YOUR aviating world.

Climb gradients, especially when flying an obstacle departure
procedure in IMC, are WAY too important to leave to chance. Your
life may very well depend on them.

Unless you have a bird with great climb performance, it all becomes a
crap shoot of sorts.

Baloney.

Especially these days when ground speed is readily available from GPS
units, no climb gradient need be left to chance.

If for some remote reason, one cannot be certain that his climb
gradient exceeds the requirement of an IMC obstacle departure, he
ought to stay on the ground until the weather lifts.

You say baloney, yet you essentially agree with me in your second
paragraph. If, for example, a ODP at an airport with a density altitude
at departure time of 4,000 feet, msl, and a required climb gradient of 280
feet per mile to 7,500, you determine with "certainty" that your bird can
do 300 feet per mile. Further, you cannot possibly determine the wind
direction and velocity with certainty in advance.

You depart with your great GPS, and leaving 6,000 find out that your
average gradient thus far has been 230 feet per mile and getting worse.
What is your certainty at that point? Beats me. The controlling obstacle
may be to the side of the containment area, or it may be a granite
ridge-line all the way across the containment area. If you try to do a
180 you are now between a rock and a hard place. ;-)