Instruments give a vast amount of information on the aircraft's behavior. It allows the pilot to see how he aircraft is behaving without outside reference. With use of information provided by the instruments, a pilot can determine speed, height (altitude), attitude, heading, and rate of climb or descent without outside visual reference. In the event a VFR pilot looses outside visual reference or is confused of the aircraft's behavior caused by deteriorating weather, vestibular illusions, darkness, or anything degrading vision to the outside, the pilot can always rely on the instruments for aircraft information in order to safely return to outside visual reference again.