If you crash on the same location your next plane spawns it's not a bug: objects don't despawn automatically by design.
The reasons are not apparent yet to most, but there is use for this in the future. A couple of years later we'll all be having better PCs and CoD will be better optimized, we might be able to have persistent online environments. Well, it sure looks better flying over the battlefield and seeing the smoking wrecks of armored vehicles battling it out, than not seeing it because they automatically despawn after a while
