Reading a book on Soviet WWII fighter aircraft, the altitude gain during a “combat turn” is mentioned, not as a measure of climb, but as a “virtue” (some English close lost in my dusty vocabulary) in itself. It would typically be 800-900m (-3000ft) for 1941 prototypes to 1500m (5000ft) for the late war Yakolev prototypes.
A 1500m height gain for a late war Yak would take at least a minute.
A 360deg turn would take about 18seconds (conditions not specified.
This leaves me with few clues to what a COMBAT TURN is…