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Just been reading some journalistic bumpf about electric aeroplanes. Nothing of any technical value, but the author seemed to intimate that we would all be flying around in electric aeroplanes by the 2030's. Whilst I recognise that electric motors driving propellers may be a feasible proposition for smaller aircraft, fail to see how one could derive the kind of thrust that a RR Trent 1000 donk generates by electrical means from batteries however big.

Thinking outside the box, replacing big aeries with lots of small aeries - max SLF of ten say, and long distance flights achieved via low space orbits. Perhaps, needs lots of thought on economics.

Alison

Think outside the square Alison. By 2030 they will have invented lightweight extension leads so all you have to is plug the airyplane in at the airport, kick the tyres, and off you go!

Alison, we're talking GREEN here not economics. Anyway, Greens were proposing emergency flights only and other mere mortals one flight in 5 years.

As people will still demand intercontinental travel they will have to travel by ship. As oil is a pollutant and nuclear is not clean I guess is will be wind power or solar.

At least the technology is proved and tested

Always thought nuclear could be the way to go given present tech:

https://en.m.wikipedia.org/wiki/Nuclear ... d_aircraft

Ah sorry. Forgot greenies hate anything fission.

Dr Quatermass designed a nuclear fuelled and recoverable rocket. Quite short and fat and weighed 1,000 tons. The experiment failed I believe.

Slasher wrote: ↑

Fri Apr 26, 2019 2:27 am

Always thought nuclear could be the way to go given present tech:

https://en.m.wikipedia.org/wiki/Nuclear ... d_aircraft

Ah sorry. Forgot greenies hate anything fission.

Get Boeing to manufacture and certify it, what could go wrong

..

Pontius Navigator wrote: ↑

Fri Apr 26, 2019 7:41 am

Quite short and fat and weighed 1,000 tons.

So after Dr Quartermass's failure he went on to invent Diane Abbot?

Wasn't the Saro Princess once mooted as the test bed for nuke powered flight?

Get Boeing to manufacture and certify it, what could go wrong ?

Ladies and Gentlemen, welcome aboard the World's first fully automatic, pilotless, aircraft. Now please sit back and enjoy the flight secure in the knowledge that nothing can go wrong, go wrong, go wrong, go wrong. click.

If it ain't Boein' I ain't goin'.

My briefcase still carries the sticker collected on a visit to Seattle .... "Boeing My Way"

Forty years ago, when I was driving an MGB and a Jag XJ6, if you had told me that forty years thence I'd be driving an electric car, which can effortlessly convey one 550 miles in a single day, mostly on autopilot in near silence and with a ride smoother than silk, and could do 0-60mph in 2.4 seconds and can do 155mph, I would not have believed you.

If you had told a British Airways pilot in 1936 that forty years from then a propellerless British Airways aircraft would be flying 99 passengers non-stop from London to New York at 55,000' and twice the speed of sound, he'd have instructed the steward to serve you no more drink.

Nowadays manned electric aeroplanes are pissy wee things the size of a Cessna 150 and are not really fit to leave the circuit. Good for a bit of basic ab-initio training, but not much else. In forty years time that will have changed beyond recognition.

Sure, the dinosaur companies such as Boeing/Airbus/R-R/GE/Exxon/Shell etc will fight tooth and claw to prevent progress in electric aeroplanes in exactly the same way that GM and Big Oil fought to suppress electric cars in the late 1990s. They will eventually fail because an innovative company will come along, probably in an advanced country like China, and produce the aeronautical equivalent of Tesla's Model S which will totally break the mould and disrupt the entire industry. The product will be vastly superior to oil-burners and will make them look as ridiculously obsolete as piston-engined cars look nowadays.

It's instructive to look at how the corporatocracy of America sought to destroy the electric car. This documentary was made a quarter of a century ago, but it's still relevant today.

Presumably it would currently be possible to build an aircraft the size of an airliner (yes, I know they vary in size) capable of flying from London to New York powered only from electricity from batteries carried onboard - maybe without passengers or any payload other than the batteries.
The drawback (based on current technology) would be the time taken to recharge the batteries (and, maybe, the speed of travel), but possible nevertheless.

Whether 'hybrids' (capable of recharging en-route) would ever be contemplated is questionable IMO.

Of course, when nuclear fusion is possible then all bets are off.

Electric vehicles have always been feasible, having both a drive chain/transmission and where battery weight can be handled, but aircraft ..... Other than propellers, cannot envisage any methodology whereby electrical energy can be efficiently turned into thrust. Suspect current battery technology max output would just be a few milliseconds of the output of a RR Trent 1000.

Alison

Heard recently that range and power on EVs is severely compromised by cold temperatures. Anybody any gen on that?

Yes, available battery capacity depends on temperature. If it's really cold then you've got problems, partly due to the fact that chemical reactions slow down at colder temperatures.
Mind you, some lithium technologies don't like heat (>40C) either. There you have the opposite problem that some reactions speed up and can get a bit over-enthusiastic if they get a bit warm.

Although hardly what we consider to be an 'airliner', there are battery-powered aircraft in existence (one of which circumnavigated the Earth) with the batteries charged and recharged solely by solar power.
Technology has to start somewhere, and it seems that electric-powered aircraft are 'possible', albeit as yet hardly competitive for commercial operation.

Sisemen wrote: ↑

Sun Apr 28, 2019 12:53 am

Heard recently that range and power on EVs is severely compromised by cold temperatures. Anybody any gen on that?

Alisoncc wrote: ↑

Sun Apr 28, 2019 12:20 am

Other than propellers, cannot envisage any methodology whereby electrical energy can be efficiently turned into thrust.

I'm pretty sure that electric aero-engines will be ducted fans. Three-quarters of the thrust of a modern 'jet' engine comes from the fan, so most of the thrust technology is already here.

At the beginning of the 20th century New York's taxi fleet was entirely electric. Lead-acid batteries were good enough for the job and much more efficient than the absurd piston-rattling technology which displaced them at the behest of the immensely powerful cabal of Rockefeller and Ford and Chrysler. Anyway, Lead-acid really wasn't up to the job for cross-country car travel.

Then along came Lithium batteries and everything changed. Quite suddenly long-haul electric driving became practical and much more enjoyable that sitting on top of a stinky noisy smoke-breathing piston-wobbler. You could never have driven Route 66 with a lead-acid battery propelling the car, but with Lithium it's a breeze.

Sure, Lithium batteries aren't the right technology for commercial air transport, but a new chemistry will come along, just like Lithium replaced Lead-acid.

Undried Plum wrote: ↑

Sat Apr 27, 2019 6:28 pm

Sure, the dinosaur companies such as Boeing/Airbus/R-R/GE/Exxon/Shell etc will fight tooth and claw to prevent progress in electric aeroplanes in exactly the same way that GM and Big Oil fought to suppress electric cars in the late 1990s.

Back in the mid-90's the then head of BP pointed out that BP is an energy company and it would be present on any new form of energy. OK they are not really active on batteries but I feel he has a point. And also I need to admit I have to watch the video.