The announcement went on: Ladies and gentlemen, please fasten your seatbelt again, we just experienced some unexpected air turbulence, the airplane was dropped 500 feet and then tossed up 400 feet. For your safety, please remain the seatbelt on. The turbulence you experience in this flight might be bigger since we have shut the engines down, letting the aircraft do its free sliding. Yes, we are free sliding because we are looking after your money in your pocket to fight the sky rocking gas price. This is a cost effective flight and we are sure that you will be enjoying the most quiet and ammusing roller coaster flight.