alt Hacker NewsSo what do regular aircraft do when they run out of fuel? They require a forced landing. Aircraft fly with a buffer of fuel though to avoid such situations, so why can't an electric aircraft fly with a similar buffer on it's range? ie. Always fly less than the current charged range of the aircraft.
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Regular aircraft are required to have enough fuel to be able to divert to the alternate airfield in their flight plan plus all the margins for taxiing and waiting for a landing clearance. If a plane is low on fuel they can declare an emergency and get priority over other traffic, but that obviously is disruptive and should not happen on well planned flights unless something pretty significant happens after takeoff.
Lots of down votes on this but it is a legitimate question. The goal is likely to have the majority of flight off of batteries. That being said, the total weight of the emergency fuel plus generators is likely far less than the weight of the extra batteries they would haul around for the safety margin they need. So they end up lighter and more capable AND don't need to burn fuel. That being said, I wouldn't be surprised if they didn't start the generators during critical phases so they may end up using some fuel for a flight, but not much. Total guess on that though.
Regular aircraft fly with enough fuel to change into at least one other airport in an emergency (ideally two).
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.
Simply put, batteries are heavy.
> Aircraft fly with a buffer of fuel though to avoid such situations, so why can't an electric aircraft fly with a similar buffer on it's range?
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.