
Boeing's very first jetliner, the 707, began commercial flights in 1958. A scant 10 years later, the demand for air travel was so great that Boeing unveiled its new 747 to the world, which held more than twice the number of passengers as the 707. Originally, the 747 was to be a double-decker configuration, but engineers struggled with freight capacity and the ability to rapidly evacuate passengers in the event of an emergency.
Eventually, a compromise was reached where the double-deck height was still present at the front of the aircraft, creating the 747's unmistakable, signature hump. On cargo-carrying variants of the 747, this clever design facilitated placing the cockpit above and out of the way of the hinged front nose section for loading. The resulting upper-deck area behind the cockpit could be utilized for additional seating or a swinging lounge and bar area. Total passenger capacity depends on how each 747 is configured, but fitting 660 of your fellow humans onboard is possible in a dense layout of exclusively economy seats.
For propulsion, the Boeing 747 relies on a brace of four turbofan engines that burn a whopping 3,500 to 3,800 gallons of fuel per hour at cruising speed. The exact fuel burn rate is dependent on the passenger capacity, as well as the particular make and model engines that are installed. Suffice to say, however, the average 747 burns about one gallon of fuel per second. Obviously, that insatiable thirst for kerosene-based Jet A-1 requires a massive fuel capacity to match.
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The Boeing 747 isn't just one of the largest commercial jets, it's also one of the fastest. Its impressive cruising speed of 580 MPH means that one mile is covered every 6.2 seconds. Using the fuel burn rate provided by BBC's Future Planet, that equates to fuel economy of 0.18 miles per gallon. While that figure is certainly shocking, one must also consider that, unlike the latest Toyota Prius, the 747 is carrying hundreds of passengers over which to amortize the expenditure.
In order to facilitate such high fuel consumption on the long-haul international routes that are typical of the Boeing 747, it carries approximately 48,400 gallons of fuel. That's enough to get you from, say, New York to London. However, longer routes like Los Angeles to Sydney require more fuel capacity still. Indeed, some variants like the 747-8i Intercontinental carry 63,034 gallons of fuel. So where does 50,000 to 60,000 gallons of fuel go? Primarily, the fuel tanks are located in the aircraft's wings, although select 747s are configured to store additional fuel in the plane's horizontal stabilizer at the tail.
Over the years, aviation authorities worldwide relaxed rules that prohibited jets with two engines from operating long overwater flights. That ushered in the dominance of modern aircraft like the Airbus A330 and Boeing's own 777 which are more fuel efficient with only two engines. Nowadays, the 747 passenger jet is disappearing, but it's not altogether gone. If you want to experience the Queen of the Skies one final time, check out our list of airlines that still operate them on certain routes.
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