co-pilot 
noun
A second pilot in an aircraft.The government regulator also issued a written warning to the two co-pilots of the charter flight....
- After the second rattling, the co-pilot can be heard asking for maximum power, Black said.
- On February 15, pilots and co-pilots voted 97.5 percent in favour of holding strike action in pursuit of their pay claim.
verb [with object]
Act as the co-pilot of (an aircraft): he still co-pilots private planes...
- In 1986, his brother Dick co-piloted an aircraft called Voyager on the first nonstop flight around the world.
- Early in the morning on Dec.13, 1968, 1st Lt. Joseph P. Fanning was co-piloting a C - 123 Provider making a ‘Candlestick Run’ over Laos.
- The performance, which involved him co-piloting a fighter plane and striding around the deck of an aircraft carrier wearing a military flight suit, reportedly cost around $1million and delayed the return of the ship.