Aviation: Emerging technologies are ushering in more fuel-efficient, comfortable and exotic aircraft. Get ready for the future of flight

It's quite ironic that as aircraft boffins seeks to strip out unnecessary weight, passengers are growing ever more obese. Personally, on those occasions when I must take a flight in the US mid-West, I wonder at what point the designer's assumptions about gross passenger weight and acceptable take-off load become invalid. At some point we're going to read about a flight that failed to get into the air because everyone on board was dozens (or even hundreds) of kilos larger than the designers expected.

My vision of the future: Enormous cattle car airplanes, travelling slowly but efficiently, with passengers not seated in chairs but strapped into a harness in a more-or-less standing position. All emergency exit doors, few windows. Mild drugs fed through the air system to keep people semiconscious during long flights. Few business travellers; most will use videopresence technology instead.

Don't overstate the pace of change. Change has been evolutionary rather than revolutionary since the 707 made transcontinental passenger jet travel common. I'm not going to hold my breath for anything supersonic, much less hypersonic.

CA-Oxonian - what you worry about has already happened at least once, with Air Midwest flight 5481 in 2003.

If wingspan is constrained by current airport infrastucture, the solution might be fold-in/out wings which are operational only once the aircraft is on the runway. Carrier based aircraft have been using these for decades, and it should not be to difficult to adapt the concept for civilian use.

Hypersonic planes could be used as missiles to deliver a "surprising hammer blow" to the enemy? Sounds like they'd be perfect for a first-use nuclear strike.

Which means that the enemy would be encouraged to launch their own nukes as soon as one of these popped up on radar.

Which means that hypersonic planes have no advantage over standard missiles.

This is the sort of story that could have been written in 1970...and probably was. Supersonic passenger travel in 2040? Back then, some people thought we could have manned missions to Jupiter by 2001 and space planes run by Pan Am. The sad reality is that what was sci fi then remains sci fi now. Another sad reality is that air travel is hellish and expensive, and growing increasingly so. Promise to reverse that trend and we the people can start caring about techie improvements.

we can instead make the wings fatter so that some people can be seated inside the wings. the front of the wing could be transparent so that the passengers can see straight ahead ... these wing passengers could be charged extra.

One of the absolute limits for wing lift is the narrow airport departure gates between airplanes. A longer thinner wing gives more lift than a short stubby wing. Having a 200 m wingspan would give remarkable lift and efficiency, but it will be untenable for airport design. And current gate distances do not allow for anything bigger than a 747 span and even then it is for special international and large craft gates.

IT is one thing to change aircraft design. It is another thing to have to revise the infrastructure for every airport in the world.

Hypersonic scramjets @ Mach 20? Thank you for trying!

What is Economist's expectations for speed of travel from my office to home everyday by 2040?

I think its great that they are trying to improve planes. In the long rune this will save money and save lives. Unfortunaly i think this will take a while to get were they want to be and be expensive to get there.

The bulk of the article wasn't all that interesting. Shedding weight seems to be an old, longstanding goal. Although the reference to 3D printing was intriguing. Hence, held off from hitting the recommend button.

However, I did find the last two paragraphs about ZEHST really interesting. Would have liked to hear further details - Like what kind of rocket would boost the craft to ramjet operating speeds?

Are ramjets more established technologies than the scramjets mentioned(I think the SR-71 operated with a hybrid engine that acted like a ramjet at high speeds)? If so, how?

Personally I think the US will push scramjet technologies for unmanned vehicles in the future, for military purposes (spying and weapons platform). Of course recent shortcomings if not failures with two tests seem to highlighted the difficulty in engineering reliable, working systems..

"Last year a lightweight, piloted Swiss aircraft, Solar Impulse, captured enough solar energy during the day to fly throughout the night."
Thats whats up, it says that that Solar Impulse flew without any fuel for 26 hours. It relied solely(lol) on solar power. With the rate at which new technology is getting out there I'm fired up to see what comes next in this category or solar power.

I'm still waiting on the flying car.

There is actually quite an easy way to reduce the weight of passengers, seat less of them. Giving more than the industry standard .5cm of leg room would cut down on the cargo weight a bit, I'm not gonna hold my breath though (cause you can't get down the 3 inch wide aisles holding a full breath).

The article says: "Some military types have enthused that...".
'Enthused'? I'm surprised to see such an ugly word in The Economist . Wouldn't "Some military types are enthusiastic that..." sound much better?
From Strunk and White's 'The Elements of Style':
'Enthuse'; an annoying verb growing out of the noun 'Enthusiasm'. Not recommended.
Maybe you should also warn against this word in your excellent Economist Style Guide.