I dont know what you mean.
You run a Stress Test
and you wondering why the fans running noisy?
My N275GTX Twin Frozr OC runs idle at 25% Fanspeed, temperature is 43°C and is barely to hear.
When i run a Stress test with FurMark Temperature rise to 75°C and the Fans adapt speed to hold that Temperature.
Then the card is louder, but not " like a airplain
i would say this is normal behaviour of your VGA card.