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!





10 responses

10 03 2017
Chris Harries

I looked at a pelican taking off the other day and my thought was that “this bird is not engineered to fly, but it does”. That plane graphic looks like a flying pelican.

Every technology seems to have an upper limit on the size factor, beyond which it is no longer practical to get any bigger. Thus CRT televisions could only get so big, before they had to get rid of it so we could enjoy wall-sized TVs. We aren’t any better off, but in this day and age make something bigger (or faster) and you’ve got a ready market.

There are some surprises though. Back in the 1970s it was surmised that a 1 Megawatt wind turbine would be at the top end of size and that going any bigger would cause those problems that come with oversize. Wrong. The biggest wind turbine now is the Vestas V164 machine, having a rated capacity of 8 MW.

Yet, like you Mike, I reckon these technological dreamers have no idea how rapidly everything will unravel before their utopian products come close to production.

10 03 2017
Doone Wyborn

So let’s go flat out with Sydney’s second airport. Stage one about $5 billion before the inevitable cost overruns.

10 03 2017

It’s OK Doone, we’ll pay for it by selling gas to Japan and Korea…….

10 03 2017
Barry Vokes

Let us try to deal with this obvious crap with as much humor as we can muster. After all, the bumblebee, from an aerodynamic standpoint, cannot possibly fly. But being ignorant of that profound scientific fact, it goes ahead and flies anyway — and manages to make a bit of honey every day.

So much of what we are routinely told by our lords and masters is pure crap. It’s true here in the USA and I do not doubt that it is true “Down Unda” as well.

You are doing good work, Mike. I remember you from the CM days. Good luck to you and I enjoy reading your posts. Sam and I are still in close touch.

The world we live in is what it is. I find that a good belly laugh every day helps a great deal. It’s better than being miserable all the time. Not that you appear miserable; unlike most, you are actually attempting to cope with what we know is likely coming our way. I wish you well.

10 03 2017

“After all, the bumblebee, from an aerodynamic standpoint, cannot possibly fly.” Not true. If you make a false assumption, then you can prove anything. For example, assuming that only quasi-steady state aerodynamic forces are involved in insect flight, you can prove that the bumble bee cannot fly.

“The first attempts to understand flapping wings assumed a quasi-steady state. This means that the air flow over the wing at any given time was assumed to be the same as how the flow would be over a non-flapping, steady-state wing at the same angle of attack. By dividing the flapping wing into a large number of motionless positions and then analyzing each position, it would be possible to create a timeline of the instantaneous forces on the wing at every moment. The calculated lift was found to be too small by a factor of three, so researchers realized that there must be unsteady phenomena providing aerodynamic forces.”

11 03 2017
Barry Vokes

That comment was never intended to be taken literally. It is an old saying in the aviation community. The point is: we need to keep our sense of humor. Much of what is happening is beyond our control. What we can control is our level of preparation for what we think lies ahead. Many of us are doing that.

11 03 2017

“… in the very little time remaining before we hit the rapids, we need to develop, test, and practice the necessary rapid communication channels and the appropriate actions to have at least some control over the “attitude” of our carrier in the turbulent section.”

10 03 2017

Sydney’s second airport is a future Stranded Asset, like coal mines. And it will become so well before it is up and running.
Re the plane. I see a goose. Probably they’ll fly in a V formation for even greater aerodynamic efficiency?

Re oil and the airline industry, a good mate told me Boeing had forecast oil will be plentiful for 1000 years. In a perverse way Boeing might be right. We won’t be able to extract it.

10 03 2017

Oh make no mistake, we will NEVER run out of oil…… but it’s not the size of the tank that matters, it’s the size of the TAP!

10 03 2017

Airlines are very, very, fuel conscious. Tiny little savings wherever they can find them; Take off is rarely at full power, the first safe exit is always used on landing, continuous course adjustment and yes less than full speed in flight. Safety first, fuel second. However, there is very little margin for error at the higher, fuel saving, altitudes of airline flying. A little faster and the airliner breaks up, a little slower and it will fall out of the sky.

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