Primarily for general aviation discussion, but other aviation topics are also welcome.
#1884512
In the interests of making sure nobody is airbrushed out. POD flew the 5km record flight and Steve Jones flew the 15km and the time to height flights.

All three are claimed as records for verification by FAI.

Great stuff from the Electroflight/RR team, but I don't really see batteries as a major part of the future of aviation. Energy density/range, failure modes, recharge time, limited raw materials resource...
Dave W liked this
#1884519
Of course where's it really all at is a translantic crossing - it would really lay bare the realities of current battery tech - I've done no calcs but my completely wide **** guess is to transport 1 person the Alcock route depending on how optimised the airframe is you'd need circa 5 tonne aircraft. So in the same ballpark as a Vimy and about as fast - but possibly more reliable -so there's your progress kind of :!: :?:
#1884557
Flyingfemme wrote:
Genghis the Engineer wrote:That's what RR get out of this, but I really wouldn't underestimate the very considerable Rolls Royce expert and skilled input that made this possible. The did vastly more than just buy in a kitplane and put some batteries and motors in it.

G

Let's not airbrush Roger out of this. It's been his baby for as long as I can remember, although the original aim was not to break a speed record - he had other ambitions.

So far as I can see he took a great concept to Rolls, but very little usable technology. The aeroplane started as the NXT, not the very immature design being taken around shows a few years ago as a fibre glass mock-up, with a variable geometry dual prop system that never saw the light of day. The battery/ motor/ controller system seems to be mainly RR & YASA.

I'm afraid that I have to say this as I see it - very well done Rolls Royce. But equally RR's objectives in reality have almost all been about capability building, not the record attempt itself.

G
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#1884558
@Kemble Pitts and @Wabash , you aren't wrong but may be missing the bigger picture.

Pure battery-electric is only likely to be much good for sport and training. However projections show massive potential for fuel cells (e.g. hydrogen or ammonia), or for battery/"other" hybrid configurations. But all of those are still essentially electric aircraft, just with additional technologies. Hence the brighter engineers in this space mostly see battery-electric as a vital stage in development towards where they really want to go.

G
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#1884559
A Cherokee sized battery powered aircraft with 2 hours endurance and 30 min reserves would cover a very large percentage of the current GA leisure/training fleet, particularly for the £100 burger run. After all, flying somewhere, having lunch is an ideal scenario for recharging. As petrol for cars gets phased out, aviation fuel will become even more expensive and harder to get hold of.
#1884568
malcolmfrost wrote:.., flying somewhere, having lunch is an ideal scenario for recharging. ...


airfields with good eateries had better invest in lots of charging stations, then :wink:
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#1884570
Wabash wrote:Of course where's it really all at is a translantic crossing - .. the Alcock route ..


ah, like UK, Newfoundland has always been a vital location in technology development :)

https://en.wikipedia.org/wiki/Signal_Hill,_St._John%27s

https://en.wikipedia.org/wiki/Transatla ... ntic_cable
Newfy liked this
#1884637
Genghis the Engineer wrote:@Kemble Pitts and @Wabash , you aren't wrong but may be missing the bigger picture.

Pure battery-electric is only likely to be much good for sport and training. However projections show massive potential for fuel cells (e.g. hydrogen or ammonia), or for battery/"other" hybrid configurations. But all of those are still essentially electric aircraft, just with additional technologies. Hence the brighter engineers in this space mostly see battery-electric as a vital stage in development towards where they really want to go.

G


I tend to agree. Pure battery/electric is at best a niche product but more likely a technological blind alley.

Now hydrogen does look to have potential, either as a combustion fuel or in a fuel cell, so long as the 'fuel tank' questions can be resolved without fitting the pressure vessel out of a steam locomotive.

I actually think that for longer range/larger aircraft (CAT essentially) then sustainable fuels that are made by sucking carbon out of the sky are the most plausible.

I've done some consultancy for one of the higher profile eVTOL operations and I just can't bring myself to 'believe'.
#1884647
Yes on all points.

Hydrogen does have a bit of a flaw, which is the energy and use of fossil fuels required to produce most of it - that is potentially solvable and the research is going on into "green hydrogen" production. If that succeeds in a similar timescale to the aircraft / powertrain development at places like ZeroAvia, then this could be a win-win.

eFuels: use of sustainable power to suck CO2 out of the air and turn it back into Jet fuel (or even Avgas) is very appealing. The realities remain rather elusive, but again, the research going on could bear fruit, and there's every reason to pursue that. And also deal with the fact that they'll still contrail - and latest research shows contrails as generating about 2/3rds of aviation's climate impact.

And eVTOL. Indeed. Harness VTOL technology that Leonardo haven't managed to certify since the AW609 first flew 18 years ago, electric propulsion several times more efficient than the best presently extant on any certified aeroplane, autonomous navigation in incompletely mapped urban areas, and do it all with untested teams faster than Boeing certified the Boeing 737-max8. It could theoretically happen, but I'd not bet my pension on it.

G
Kemble Pitts liked this
#1884675
Genghis the Engineer wrote:
Flyingfemme wrote:
Genghis the Engineer wrote:That's what RR get out of this, but I really wouldn't underestimate the very considerable Rolls Royce expert and skilled input that made this possible. The did vastly more than just buy in a kitplane and put some batteries and motors in it.

G

Let's not airbrush Roger out of this. It's been his baby for as long as I can remember, although the original aim was not to break a speed record - he had other ambitions.

So far as I can see he took a great concept to Rolls, but very little usable technology. The aeroplane started as the NXT, not the very immature design being taken around shows a few years ago as a fibre glass mock-up, with a variable geometry dual prop system that never saw the light of day. The battery/ motor/ controller system seems to be mainly RR & YASA.

I'm afraid that I have to say this as I see it - very well done Rolls Royce. But equally RR's objectives in reality have almost all been about capability building, not the record attempt itself.

G


I'm sorry but this is not true. The entire propulsion system, it's integration the airframe modification was all carried out by Electroflight with RR leading safety and flight test. I know this because I did it... I previously offered to email you some presentations so that you have all the facts. Please stop guessing or assuming on the program details. Of course you are clearly knowledgeable on the wider technology and always good to share different view points.

You are right that there was no link to the P1E as Electroflight under my guidance took another direction.

The program is not an attempt to demonstrate battery electric aircraft but to fly a high power electric propulsion system. The battery system requirements of a record run are more aligned to hybrid electric propulsion systems.
Rob P, Flyingfemme, wigglyamp and 2 others liked this
#1884715
Sorry if I struck a nerve there, but given that all of the published material, the public lectures, conference presentations, press releases talk all about the Rolls Royce effort supported by Electroflight and others, and even electroflight's own website only lays claim to the battery pack then re-routes you to Rolls Royce's website- it is a pretty obvious opinion to hold. Not to mention that the aeroplane has "Rolls Royce" plastered all over it.

If this really is an electroflight project supported by Rolls, and not the other way around then some very stern words should be being had with Rolls' various parts, and for that matter whoever is managing Electroflight's website for you.

My email address is boffin at engineer dot com, but links on this discussion might be more informative. But I *am* taking my information from what is in the public domain mainly, although backed up by the usual industry gossip. I'm certainly not making things up.

That said, my apologies for not recognising Electroflight's leadership on the energy storage technology, as that is absolutely at the core of delivering electric flight, and a massive set of engineering problems to solve. The rest of it is far from trivial, but without the battery system, you may as well not bother trying. And without a doubt, the basic concept of this high performance electric aeroplane, and all you can learn from it, originates with Electroflight and nothing would have even started without them.

G
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