Commercial or passenger aircraft are usually designed for optimum performance at their cruise speed or VC. Combustion engines have an optimum efficiency level for fuel consumption and power output. Generally, piston engines are most efficient between idle speed and 25% short of full throttle.
The blood to your head rushes when you do a quick movement, so, naturally, dizziness is expected. I think the blood rushes from your head too fast. it is called postural hypotension.. whereby, due to getting up suddenly to a upright position, there is lower blood supply to th head.
1 Light headedness: The medical term for this feeling is âpresyncope.â This feeling of being lightheaded can involve feeling dizzy and nauseous, having pale or clammy skin. 2  Blood pressure drop: A sudden drop in your blood pressure can cause this type of dizziness.