Dolphin flying

On Monday, February 15, 2016 at 1:48:59 AM UTC-5, krasw wrote:
On Sunday, 14 February 2016 04:57:42 UTC+2, Dave Nadler wrote:
On Saturday, February 13, 2016 at 10:34:32 AM UTC-5, Soartech wrote:
Hint:
http://www.onlinecontest.org/olc-2.0...htId=185517315

See ya, Dave

Dave, What is your point here?

MacCready theory is not always applicable.
Consider:
- What are MacCready theory's assumptions, and when are these not valid?
- Why do good flights often beat expected MC speeds (after accounting
for start-finish altitude differential)?

Hopefully this will be covered in the V3 talk at the convention;
Tilo tells me by analyzing OLC piles of flight logs, the actual
behavior of top pilots shows this, thus better informs how the glider
should be optimized...

Hope this helps,
Best Regards, Dave

Are you saying that MC theory is not valid for gliding long distances using continuous lift?

Read Brigliadori as he describes extended glide. MC is based on a a model of climb and glide that does not apply directly much of the time, especially with higher performance gliders.
UH

On Monday, February 15, 2016 at 4:45:15 PM UTC+3, wrote:
On Monday, February 15, 2016 at 1:48:59 AM UTC-5, krasw wrote:
On Sunday, 14 February 2016 04:57:42 UTC+2, Dave Nadler wrote:
On Saturday, February 13, 2016 at 10:34:32 AM UTC-5, Soartech wrote:
Hint:
http://www.onlinecontest.org/olc-2.0...htId=185517315

See ya, Dave

Dave, What is your point here?

MacCready theory is not always applicable.
Consider:
- What are MacCready theory's assumptions, and when are these not valid?
- Why do good flights often beat expected MC speeds (after accounting
for start-finish altitude differential)?

Hopefully this will be covered in the V3 talk at the convention;
Tilo tells me by analyzing OLC piles of flight logs, the actual
behavior of top pilots shows this, thus better informs how the glider
should be optimized...

Hope this helps,
Best Regards, Dave

Are you saying that MC theory is not valid for gliding long distances using continuous lift?

Read Brigliadori as he describes extended glide. MC is based on a a model of climb and glide that does not apply directly much of the time, especially with higher performance gliders.

It was initially derived that way, but I believe it *applies* to other situations too.

If you are running along under a cloud street, the slow thing is to fly just under the clouds speeding up in the lift so you don't get sucked into them, and slowing down when that danger is past. The fast thing is to increase your MC setting (and fly it) enough that you fly fast and drop below cloudbase sufficiently in weaker lift that you can slow down and pull up in lift without entering the clouds.

For high performance gliders the main modification to MC theory is that the conventional output is "speed to fly". The real output should be "angle of attack to fly".

At speeds around 40 - 60 knots they are quite quickly the same thing. But over 100 knots it means that you are simply pulling increased Gs in lift and decreased Gs in sink and you might well pass through the area of lift of sink with very little change in airspeed.

Intuitively, you're "bouncing off" the lift. And sink can't rob energy from you while you're in a low drag near zero lift configuration.

maanantai 15. helmikuuta 2016 15.45.15 UTC+2 kirjoitti:

Read Brigliadori as he describes extended glide. MC is based on a a model of climb and glide that does not apply directly much of the time, especially with higher performance gliders.
UH

I have and have read Brigliadori. It's still challenge to prove MC theory invalid, it has been attempted many times. MC theory applies under cloudstreet, there is optimum speed for current lift or sink.

BTW Brigliadori has nonsense in some parts of the book. I would take everything with at least a grain of salt.

MacCready theory is perfectly valid for both thermal soaring and cloud-street dolphin flying as long as the assumptions under which the theory is valid hold. Since this is almost never, flying at an appropriate MacCready setting may not be optimum under any conditions!

Out west, you run the risk of flying into the ground when thermals are widely spaced and perhaps short-lived - hence the recommendation to slow as you get lower.

Under a solid cloud street, MacCready can give you good guidance overall, but goes out of the window if you have to fly fast in lift to stay out of cloud!

Mike

McR theory are correct in almost all conditions, could be that on the ridge with dynamic lift should other theories be used.

But with that said di I also have to say:
The master of McR theory will never outperform the master of finding good climbs and the master of finding the best route.
I spend very little time and energy in decisions on STF, I try to spend most of my time and energy to find the best route and to get the best climbs. And most important of all, avoid the bad climbs.

On Tuesday, February 16, 2016 at 8:46:08 AM UTC-5, Per Carlin wrote:
McR theory are correct in almost all conditions, could be that on the ridge with dynamic lift should other theories be used.

But with that said di I also have to say:
The master of McR theory will never outperform the master of finding good climbs and the master of finding the best route.
I spend very little time and energy in decisions on STF, I try to spend most of my time and energy to find the best route and to get the best climbs. And most important of all, avoid the bad climbs.

Yep- right and left is much more important than up and down.
UH