Mooney_Driver wrote:
They switched not because of the Chinese ownership but because of the bancruptcy at the time
I noted the US military switch from Rotax to diesels. They did it because they didn’t want to supply 100LL in the field anymore. Rotax is a perfectly viable company with great products. In specific Rotax certified the 914 tubo just for the US military drone program. Those days are apparently over now.
Peter wrote:
A hybrid power train makes no sense for a constant power output application. It is only in apps like cars (which run at 10-20% power a lot of the time) where it can make sense to have a small IC engine working as a battery charger.
…
A typical GA plane (excluding power gliders) needs something like 40% power to fly at Vbg (economical but nobody flies that slow) or 65% power to fly at some kind of normal cruise.
You are right, but I think this is a bit of chicked & egg problem. Typical GA plane is designed around typical GA engine – if you made it more slippery so that you can use smaller engine for a still reasonable speed, it would have abysmal takeoff and climb performance.
To make real use of a hybrid powertrain, you would want to design the airplane around it. Perhaps you can then use plenty of smaller propellers (cheap/proven from delivery drones?) and save something on control surfaces, undercarriage length and who knows where else… Perhaps you can use the electric boost to quickly power through an icing layer. …
Still, the problem is small GS market, so the crucial would be to leverage the developments from mass markets (hybrid cards, drones…).
Emir wrote:
It’s expected to be raised to 1800 and 1500 respectively but nothing confirmed officially.
Yes, but is anything confirmed unofficially? 
I mean, is that just a wild rumour or is there any credibility to it at all?
I got this info from my mechanic who’s pretty experienced with maintaining CD and who made few C172 conversions to CD-155.
What does the exchange cost?
Following up on my previous posts on the Lycoming (ex-VM) Diesel powered UAV, I note with interest that I may have been incorrect about US Army adoption of the Lycoming… but I’m not sure.
The Army ordered 19 Improved Grey Eagles (IGEs) late in 2015, and IGE was the name used for the 2013 Lycoming powered prototype, but none of the current press releases describing both the new Army order and the scope of IGE ‘Improvements’ mentions any engine change away from the ex-Thielert used in earlier Grey Eagles. Given the politics and the technical significance of any engine change I think it’s interesting to conjecture why: support for military Thielerts figured out so political problem now gone? Maybe a different new engine (Austro)? Lycoming Diesel still needing development so uncertainty in the program? I guess time will tell, but anyway I couldn’t figure it out from published information.
tomjnx wrote:
Currently, gasoline has 44MJ/kg, while lithium ion rechargeable batteries are somewhere up to 0.875MJ/kg, so assuming yearly 30% improvement we would indeed get decent range in 15 years.
Petrol engines are only about 30% efficient. Electric propulsion is in the upper 80s of % so the energy density of a battery doesn’t need to equal that of petrol.
However, I don’t think we’ll be seeing anything other than sport aircraft with electric propulsion for an awful long time.
That’s true but taking the wider picture, a standard steam-cycle power station has a theoretical efficiency ceiling of around 40%, and electricity isn’t going to be cheap like it is now once it starts to get heavily used in place of liquid fuels.
Even if one could make an electric “circuit bashing” trainer type, and I think one almost can do it now, I wonder how many schools would buy it, given that they would get very little self fly hire business out of it – because such a plane would be useless for anything but the shortest imaginable burger run. So there are angles which are not driven by pure technology possibilities.
But we have had numerous “electric plane” threads 
The above view would apply to any engine which works well and reliably in the training environment but for whatever reason isn’t good for going anywhere.
Peter wrote:
I wonder how many schools would buy it, given that they would get very little self fly hire business out of it
Peter, a lot of flight schools either don’t offer their primary trainers for hire at all or are rather reluctant to do so. Exception of course being the x-country flights the students have to take. I’m pretty sure we’ll see electric trainers with swappable battery packs appear on the scene relatively soon.
Electricity IS going to be cheap as supply is rather unconstrained and costs of production go down as tech prices go down.
If Germany has already reached negative electricity prices with the current generating facilities, the switch from oil to spark isn’t going to change much as exponentially more generation comes online.
