Comment by stavros
PLA is pretty bad compared to foam when it comes to planes, as it's very heavy and very brittle. Any semi-hard landing will break parts off, and heavy planes fly badly.
The big advantage is that you can just print the part again, which almost makes PLA worth it.
ABS would probably be better, as it's much more durable and lighter, but it's still much heavier than foam, and printing ABS isn't great.
I used single wall foaming PLA which has filament density of ~0.45 g/cm3 at 250 degree nozzle temp, about 64% lower than normal PLA. But it is even worse for impact resistance than normal PLA. Weight was the primary driver for this plane