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On the figure above, you can see different values of speed to fly value related to
different flight conditions.
The X-axis shows horizontal speed, the Y-axis shows sink rate. In a head wind or sink
conditions, the best glide speed increases. In order to find the optimum speed to fly
value in sink, you simply add the sink of the air to the polar of your glider, drawing a new
polar and a new tangent line from the initial point of axes. The new tangent (point D)
meets the polar at the point giving a higher optimum flying speed VD.
To obtain the correct “Speed to fly”
you have to adjust your speed so
both McCready arrows are in the
same position.
6.6
McCREADY
To utilize the McCready functions, you must have an air speed
probe connected. The optional air speed probe should be
plugged in to the right hand socket on the bottom of the vario.
If this parameter (ADVANCED SETUP \ n. 8 POLA) is set to “OFF”, all display
information relating to McCready, McCready Equivalent, Thermal Sniffer is not
displayed on the instrument, creating a cleaner display for users not needing this
functionality.
The McCready value is the average lift value from last 10 minutes. The average time
can be adjusted, go to (ADVANCED SETUP \ n. 18 MCRA).
Equiv. McCready
McCready
Optimal Good Bad
- Speed to fly indications -
McCready
