Boeing 727 " a tri motor".

The Boeing 727 is a mid-size narrow-body three-engine jet aircraft built by Boeing Commercial Airplanes from the early 1960s to 1984.^[1] It can carry 149 to 189 passengers and later models can fly up to 2,400 to 2,700 nautical miles (4,400 to 5,000 km) nonstop. Intended for short and medium-length flights, the 727 can use fairly short runways at smaller airports. It has three Pratt & Whitney JT8D engines below the T-tail, one on each side of the rear fuselage with a center engine that connects through an S-duct to an inlet at the base of the fin. The 727 is Boeing's only tri-jet aircraft.