General Interpretation

Specific Power curves have been produced for the two MiG variants and the three Sabre variants for an altitude of 20,000ft. Additional curves for the MiG15 and F86a have also been produced for 10,000ft and 30,000ft. For each curve it is possible to extract the following information:

Maximum Instantaneous Turn Rate

This occurs at the intersection of the lift limit line and the maximum g line. So for instance, on the F86a at 20,000ft this occurs at 20 deg/sec and a speed of 0.62M. In practice this condition is very difficult to achieve. If a break turn is initiated at high speed, then the speed bleeds off quickly and will be below 0.6M before the maximum turn has been achieved. Turn rates of about 16 degrees/ sec have been achieved on the model.

The Maximum Instantaneous Turn Rate is lift limited and cannot be sustained.

Sustained Turn Rate

The sustained turn rate, which depends on available thrust and the drag on the airframe, is obtained by finding the maximum on the Ps = 0 curve. On the F86a at 20,000ft this occurs at about 6.5 degrees/sec at a speed of 0.42M.

It is important to realise that a pilot does not fly his aircraft at this condition by pulling back hard on his stick and flying the lift line. Inspection of the diagram shows that the pilot flying in this way will only achieve a turn rate of 5 degrees/ sec and he will have slowed down to about 0.25M. He will be flying at the point where the Ps=0 line intersects the lift limit.

It is easier for the MiG pilot to fly the sustained turn rate at 20,000ft because the maximum turn rate coincides with the lift limit line.

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Minimum Turn Radius

Turn radius lines are displayed on the diagrams. On the F86a at 20,000ft, it can be seen that the minimum radius is between 1500-2000ft. Generally the minimum turn radius is obtained by drawing a line from the origin which produces a tangent to the lift limit line.

Maximum Climb Speed

This is a difficult quantity to determine from the curves and so, at some point, we will present the data in a table. However for the MiG15bis at 20,000ft the Ps=100ft/s line is available. From this it is possible to estimate the maximum Ps position on the x axis. For the MiG15bis it will be just over 0.7M.

To download the set of energy charts for MiG and F86 variants click HERE 750K.