1968

Boeing 747 Jumbo Jet

Joe Sutter (b. 1921)

The 747 jumbo jet appeared to the world in 1968. Commissioned by the Boeing Airplane Company, its chief engineer, Joe Sutter, managed the design team behind the jet. The 747’s immensity surprised everyone. Never before had the public seen a commercial aircraft with two floors and a staircase. The 747 also introduced the concept of a wide-body jumbo jet with two aisles and ten seats to a row. With over 600 passengers onboard in the densest seating configuration, the 747 would hold the passenger record for nearly four decades. It was two or three times bigger than other passenger planes at the time.

What happened? How could such a huge airplane pop into existence? Two engineering advancements made the 747 possible: the development of powerful high-bypass turbofan engines, and high-lift wings. The engines provided three big advantages: 1) much higher thrust than the low-bypass turbofans of that era, 2) much better fuel economy, and 3) noise reduction. Huge retractable flaps and slats increased wing surface area and curvature for short takeoffs and landings.

The size of the 747, combined with its high-efficiency engines, make possible a tremendous range. The 747-400 holds nearly 60,000 gallons (227,000 liters) of fuel in its wings, cargo area, and tail. Some variants of the 747 can fly over 9,000 miles (14,500 km) without refueling. That sounds like an abysmal 0.16 miles per gallon (.07 km/L). But if there are 600 passengers on board, it is 100 mpg (42 km/L) per passenger at Mach 0.85.

Where does the 747’s hump come from? One goal of the 747 is to be both a passenger plane and a cargo plane. A real cargo plane needs a door at the front, with the nose of the aircraft able to rotate up for full access to the cargo area. This requirement meant that the cockpit needed to be above the cargo area rather than in the nose. Aerodynamic considerations demand that engineers build a tapered area behind the raised cockpit to smooth out airflow. That tapered area extends all the way back to the wings, and became the second floor—an engineer’s creative use of the aerodynamically required space.

SEE ALSO Turbojet Engine (1937), C-5 Super Galaxy (1968).

Mock-up of 747-100 cabin, March 1967.