View Single Post
  #4  
Old October 26th 14, 04:04 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 19
Default alternative McCready theory and variometers

On Sunday, October 26, 2014 8:43:45 AM UTC, Tibor Arpas wrote:
My ideas for features:

* showing equivalentMC http://www.lk8000.it/new-20-features...t-mcready.html
* automatic MC set from equivalent MC


As I understand it, 'Equivalent MC' reverses the STF calculation, and produces a figure from your averaged airspeed and the polar for your aircraft.

For example, assume MC theory for a glider states a STF of 150kph for a 2.0m/s estimated climb. 'Equivalent MC' reverses this equation; If you fly this glider at a constant 150kph IAS for the averaging period, the 'Equivalent MC' will be 2.0m/s.

The way I've heard it described, the idea is that you directly compare your 'Equivalent MC' figure with your MC figure and adjust your airspeed accordingly. If 'Equivalent MC' = 2.1m/s and MC = 2.0m/s, slow down. If 'Equivalent MC' = 1.9m/s and MC = 2.0m/s, speed up.

Climb and sink does not directly influence 'Equivalent MC', which is one reason why 'Equivalent MC' might be a poor value to display on a vario.