A pilot once told us a story about an accident on an early morning flight in the 1950s. As the aircraft accelerated to take off, the captain noticed his flight engineer’s sullen expression and called out, “Cheer up, George.” But in his sleepy state, what the engineer heard was, “Gear up, George” — and he duly raised the landing gear — prematurely as they were not quite airborne. The aircraft sank onto its fuselage and slid to a halt, causing much damage. Luckily, nobody was hurt.