The Balance between "% Circling" and "MacCready Speed to Fly"

On Jul 5, 5:33*am, Papa3 wrote:
On Jul 4, 10:06*pm, Nine Bravo Ground wrote:



Overall, you need to set your cruise based on McCready for your
expected ACTUAL climb rate, including centering time and other
considerations such as changes in climb rate at the top or bottom of
the climb (Cochrane explains this pretty well in his papers) -
different pilots estimate this in different ways, some computers give
bottom-to-top averages as well. *The net effect is slower climb rates
than you might otherwise estimate based on staring at you 30-second
averager.

9B

Just a quick note on this point. *I've been informally checking with
pilots for several years after flights on our local DIY contest here
to calibrate the actual conditions against my weather forecasts.
Often times, I'll hear that it was a "great day - I was hitting
5-6kts". * Post flight analysis of several traces reveal that achieved
climbs were more like 3-4kts at best. *It's very clear that we don't
do a great job of accounting for our centering losses and hanging in
for too long once the lift tails off. By the way, * in the good old
days before flight recorders, it seems that lift was a lot stronger.
Maybe it's weight of the FRs that's slowing things down :-)

I think I know where most of the weight changes in my ship have come
from...

This has been discussed before, but bears mentioning in this context:
It is not really worth spending much attention on the speed director
of your vario/computer. It takes a fair amount of attention that is
far better spent on race strategy and tactics. This applies both to
setting the McCready for general speed to fly and chasing the speed
director for localized lift/sink.

I tend to fly three speeds - 80-85 knots for "normal" conditions,
90-95 knots if it is super strong and consistent with clouds and
streeting and 70-75 knots if it is weak, I need a long glide or I am
low (this is all dry - add 5-10 knots for water). This is pretty
consistent for most racing pilots I know. Best L/D for my ship is 60
knots so there is no point in ever flying less than 70 (McCready 1).
There just isn't that much difference in glide angle (L/D of 45
instead of 47 on the factory polar) so slowing down by the additional
15% is just giving speed away. Similarly, the knee in the polar is
somewhere around 85 knots, so it has to be really strong to motivate
me give away altitude at a higher rate.

9B