> 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.
To that point, the battery capacity they’ve got, rough envelope math, is maybe 10 minutes beyond reserve. They’d likely need at least double, probably triple battery capacity to fly useful routes all-electric with enough reserve stored in batteries. The turbines are a great move.