Because the required buffer is HUGE and we’re at a point where electric planes barely have enough energy for the actual route. So they’re doing the sensible thing here, flying the actual route electrically and falling back to combustion if the plane needs to divert.
Yup. And to bring this point home:
"Only" doubling the battery capacity likely eats well over half of the payload capacity, in terms of mass. So your 38 seat plane is now a 19 seat (or fewer) plane.
You make it sound like it is acceptable for a badly planned flight to have a fuel emergency. It is not.
If there is a fuel emergency (or the plane lands with less than 30min of fuel) there will be an incident investigation that treats the situation as serious as if the plane had crashed. If the investigation discovers it was nothing more than bad planning, (at minimum) the planning procedures will be changed to ensure it never happens again.
The pilots took exactly enough fuel to reach their destination. They didn't have enough fuel to divert to an alternative airport. They didn't even have the mandatory 30min of reserve fuel. They did not account for a minor holding pattern just before landing (ironically, because another plane had a fuel leak).
The crew failed to declare a fuel emergency, and crashed 18km from the airport. They had only been in the hold for 10 min when their engines ran out.. they were very short of fuel, the pilots knew they were short. They should have diverted (or declared a fuel emergency) almost an hour earlier, but they didn't want anyone to know how close they were cutting it.
No the investigation isn’t as serious as if the plane had crashed. In July 2026 nine planes simultaneously had a fuel emergency in London. You bet it’s different from nine planes simultaneously crashing in London.
It helps to understand different kinds of fuel emergency. Declaring a fuel emergency to get to a diversion airport is very very different from having 30 minutes of fuel left.
But still very serious. 9 simultaneous fuel emergencies could have easily overwhelmed ATC and snowballed to worse issues.
Something lead 10 different aircraft to make the exact same mistake and find themselves without enough fuel for a safe diversion. There will be recommendations to try and prevent it from happening again.
That aircraft would need a very large battery to do that, and it's way more efficient to have some burnable fuel there that you'll never actually use.
I somewhat doubt that. Part of the advantage of the design is that the generators don't need to be sized as big enough to power take off, climb and a potential go-around on landing. They only need to be sized as big enough for cruising.
So powering them up during critical phases wouldn't help with safety. If anything, normal operating procedures might actually require shutting them down during critical phases.
What this does mean is that the batteries need to be reasonably full when it comes into land, possibly as high as 50%. And most go arounds will require immediately powering up the generators, so it probably needs to be fuelled for all but the shortest flights.
I would guess the opposite. Many parts in a turbine engine are "lifetime limited" by number of engine starts. That is, you are required to tear down the engine and replace certain parts after a certain number of engine cycles.
That makes the economics of the turbine hybrid radically different if you need to start it every time you land vs. only the rare cases where you need to dip into fuel reserves.
For example, the PT6A (a common 500-1000hp turboprop) requires the turbine and compressor disks to be replaced every 16,000 cycles. That's about 5 years of commercial service at 4x round trips per day. But if you only start the engine once in every 10 flights, now those components (theoretically) last for 50 years of flying.
There aren't that many existing flight routes that will fit into the 125 mile range (though the existence of this plane might change that), so I suspect we will see most of these planes go into service on slightly longer routes. So they will probably still need one cycle per flight.
Though... The video isn't quite clear if the 125 miles is what they can fly without starting the turbines or if it's what they can fly without needing the turbines ready to act as an emergency reserve. I actually suspect it's the later and this aircraft can make it to 200+ miles without starting the turbines.
Where I live, there aren't that many 125 mile flights, but there are a lot of 200 mile fights.
I also suspect the turbines are sized so that only need to start one of the two turbines on most flights, which would extend lifetime a lot. Ideally the turbines would be sized so that one is enough for cruising, and with two you can actually charge the batteries after a go-around (enough to enable a second and third go-around)