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.
Why does my blood pressure drop when i stand up? Okay so i'm 13 and i went to a naturalpath and she asked if i ever got dizzy and I said ya when I stand up so she made me lay down and she put the thing on that shows your blood pressure and she made me stand up and it dropped a lot.