By: Toby Martin-Kohls
Airlines have flown many routes over the course of their existence, mergers, recessions, and some routes we have today were the same as routes that were used in the 1960s. American Airlines has flown between New York and Los Angeles for many decades. They have had a daily service leaving New York at 12:00pm daily since the 1960s.
The 1967 version of this flight took a grand total of 5 hrs and 43min long for travel time. Today’s version of this flight is listed at 6hrs and 27min. In reality, in this example, the time spent in the air is the same. Today’s schedules now account for congestion and delays at airports, and things going wrong.
We have made many advancements in technology in the last 50 years, so why is the flight time longer or still the same?
Let’s take a look at how airplane engines have evolved. There are 3 main types of engines. They are the turboprop, the turbofan, and the turbojet. Each of them has a range of speeds at which they are most efficient.
The turboprop is what you will most likely see on propeller aircraft. Almost all of the thrust from turboprop engines comes from the propeller. These engines are typically inexpensive to buy and operate so a lot of smaller commuter planes use these engines. Of course, the trade-off here is that they are not as fast. They are most efficient at speeds of 325mph to 375mph. Any faster than that and it is better to use a turbofan.
Turbofans are the type of engines that you can see pretty much everywhere. Almost every commercial aircraft is turbo fan-driven. Turbofan engines are most efficient at the speeds most aircraft fly at today, 400mph to 620mph.
If you want to go supersonic, you would have to go above 767mph, and you would need a turbojet engine. Turbojet engines are very similar to turbofan engines, except all the air goes through the engine’s turbine. This lets the engines reach really high speeds, but they also require immense fuel. The engines are really only efficient between 1,300mph and 1,400mph.
The Concorde used a turbojet engine to go supersonic. It burned 46.85lbs of fuel per every mile flown. To put this in comparison with an aircraft used today, that is using new technology to become the most efficient, the new B787-Dreamliner consumes 18.7lbs of fuel for every mile flown.
Compared to today’s commercial planes, the Concorde was pretty small. It held 100 passengers, compared to 291 passengers on the Dreamliner. The per-person fuel economy on the Concorde was around 14mpg, compared to 104mpg per passenger on the Dreamliner.
There were only two commercial airlines that flew the Concorde, which was British Airways and Air France. They could not afford to keep flying the plane. Less than one-third of the seats were actually occupied by paying customers. Other seats were occupied by using miles to pay for their seat or upgrades from first class on normal flights. It cost a minimum of $7,500 (adjusted for inflation) to fly one way from London to New York in 3hrs, in seats that look very similar to economy class today.
British Airways introduced its first Business Class lay-flat seat in 2000, and many opted to choose this 7hr flight in comfort instead of the Concorde.
The whole idea of the Concorde was to create the most efficient way to cross the Atlantic for business travelers, but now in the early 2000s, travelers from the U.S. could book 7hr flights leaving in the evening, sleep on the plane, and wake up in Europe.
The Concorde is not the best luxurious or efficient option anymore. Its last flight came on October 24, 2003, ending the era of commercial supersonic flight.
For the airlines, speed doesn’t really matter. It really only exists as a selling point for the consumer. The cost of the airplane is a relatively small part of the overall cost to fly so you’ll never see an airline fly faster so they can use their planes more.
Plane’s lifespans are generally rated in cycles; the number of times a plane takes off and lands. The Dreamliner we talked about earlier has a lifespan of 44,000 cycles and a list price of $224.6 million, which is often higher than the actual sale price. That means the cost of the airplane per flight is $5,104.54, while the fuel cost to operate a flight from New York to London is $18,727. Therefore, airlines just always fly their aircraft at the most efficient speeds. That speed is almost always between 500-550mph.
That is well below the speed of sound, which is 767mph. Why don’t planes fly just below the speed of sound? Flying at just below this speed is flying in the Transonic Range, which increases drag, and destabilizes the aircraft, which would be quite dangerous. Flying in this range (Mach 0.8-Mach 1.2) actually requires more fuel than flying above Mach 1.2. So essentially, the speed limit for commercial aircraft to be economically viable is 613.8mph.
With current speeds, airplanes are able to fly anywhere on earth within 24hrs. The barrier for most people to travel is cost, not speed, so manufacturers and airlines will continue to focus their efforts on driving down the cost of travel, not the time. In the end, time is the money of only a privileged few and cost is the enemy of the masses.
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