Hi Gripen,
>Yeah, HoHun is mostly right but it should be noted that structural strenght is not allways limiting factor at high speed turns because compressebility constrains maneuverability specially at high altitudes.
Good point! It fits well with what I wrote, however, if you consider that corner speed increases with altitude until the aircraft will have difficulties actually reaching corner speed.
For example, an aircraft with a 110 mph stall speed at 1 G and a 9 G structural limit has a corner speed of Mach 0.43 at sea level. At about 23000 ft, it's corner speed will be Mach 0.68 - which is the P-38's critical Mach number. If our fictitous aircraft is similarly Mach limited, at higher altitudes, corner speed simply is beyond its capabilities.
By my definition, it can only make "low-speed turns (below corner speed)" above that altitude, though I admit that this term might be somewhat misleading as actually, the aircraft is going very fast :-)
Regards,
Henning (HoHun)