The Ki-27 is more durable in game than it should be.
The Ki-27 Rookie A/I is also very good.
When landing and taxiing on runway (tested on concrete and grass) the tail bounces and continues to bounce when the plane has stopped.
And, after Ki-27 planes land on the ground - when hit during a ground attack (even before the attack), they will flip over on their backs or noseover but not have any visible damage.
Tested in 4.12 and 4.13
I noticed this problem several years ago and I'm surprised that this has not been fixed yet.