Peak Airplane Speed

10 03 2017

Having just flown over 5000km (return) to visit my family for my recent retirement milestone, I was attracted to this story… and I have to say that while everyone else in the plane takes the experience for granted, it never ceases to amaze me when it takes off that we are able (still..?) to do this.

Recently, a story surfaced on Facebook that had me in stitches…:

Airbus is looking to a future faster than the speed of sound as it filed another patent intended to help aircraft fly supersonically.

Details have emerged of a (sic) application filed in the US by the pan-European aerospace company for a design of a spaceplane capable of taking off and landing like a normal aircraft but able to fly at supersonic speeds at altitudes “of at least 100 kilometres”.

Even funnier, it was illustrated with the following image……

Image result for patented supersonic airbus

Just look at that thing…….. it doesn’t even look like it can fly, way too fat for its wings, almost a cartoon of an airplane actually. And I doubt any plane manufacturer has ever taken out a patent for an entire plane. Bits of planes, for sure, but a whole plane..? Which goes to show you can’t believe anything you read in the Telegraph, though mind you, it seems quite a few other media outlets were also taken in…… there’s a hilarious video by some unknown Indian man demonstrating how little he knows about aerodynamics there too.

Even if this were serious, it would never fly, because it takes years to develop projects like this, and I doubt that plane manufacturers are not aware of our energy predicaments, even if they son’t say so publicly.

Then along comes this latest article from Ugo Bardi……

So, it is true: planes fly slower nowadays! The video, above, shows that plane trips are today more than 10% longer than they were in the 1960s and 1970s for the same distance. Airlines, it seems, attained their “peak speed” during those decades.

Clearly, airlines have optimized the performance of their planes to minimize costs. But they were surely optimizing their business practices also before the peak and, at that time, the results they obtained must have been different. The change took place when they started using the current oil prices for their models and they found that they had to slow down. You see in the chart below what happened to the oil market after 1970. (Brent oil prices, corrected for inflation, source)

It is remarkable how things change. Do you remember the hype of the 1950s and 1960s? The people who opposed the building of supersonic passenger planes were considered to be against humankind’s manifest destiny. Speed had to increase because it had always been doing so and technology would have provided us with the means to continue moving faster.

Rising oil prices dealt a death blow to that attitude. The supersonic Concorde was a flying mistake that was built nevertheless (a manifestation of French Grandeur). Fortunately, other weird ideas didn’t make it, such as the sub-orbital plane that should have shot passengers from Paris to New York in less than one hour.

If this story tells us something is that, in the fight between technological progress and oil depletion, oil depletion normally wins. Airlines are especially fuel-hungry and they have no alternatives to liquid fuels. So, despite all the best technologies, the only way for them to cope with higher oil prices was to slow down planes, it was as simple as that.

Even slower planes, though, still need liquid fuels that are manufactured from oil. We may go back to propeller planes for even better efficiency, but the problem remains: no oil, no planes, at least not the kind of planes that allow normal people to fly, something that, nowadays, looks like an obvious feature of our life. But, as I said before, things change!