Complex sentence: Note that at high flight speeds (ignore the change in altitude), the hot nozzle is usually in, or close to, a choking condition, because the ram rise in the air intake factors-up the nozzle pressure ratio.
Split into simpler sentences: Note that at high flight speeds (ignoring the change in altitude), the hot nozzle is usually in, or close to, a choking condition. This is because the ram rise in the air intake factors-up the nozzle pressure ratio.