Wouldn't that depend more on what kind of munitions that cannon is using? I mean their APDS uses like a 30mm depleted uranium dart, which would punch a clean hole through the fuselage and probably not do much "dangerous" damage to the plane. On the other hand if it was a HEAT SABOT then yeah I'm pretty sure if it hit the fuselage or more than the very tip of the wing the plane is going down... the sheer force of the explosion would cause whatever it hit to come off the aircraft. But if it was just the KE Sabot round that is literally a very fast moving dart there wouldn't be a whole lot of damage I'd imagine.