When the aircraft is accelerating, the sense organs of the inner ear of the pilot send a signal to the pilot’s brain that is interpreted as tilting backwards instead of accelerating forward. If the aircraft nose is simultaneously raised, the pilot has a very strong sensation of climbing. The illusion of false climb tends to lead the pilot to lower the nose and descend. The aircraft then accelerates and the illusion can intensify.
This is part of the reason why one is taught a thing called
instrument flying.