The effective range of an AK is quite a bit less than that. If the news of casualties is correct, then the aircraft was punctured by bullets which is serious, even the cockpit would be easy to hit.
However, please remember that approach "funnel area" at the Runway threshold extends quite a bit onwards and it incorporates both the "over-run" gravel/sand area and then the approach lighting even beyond that. All of that is (or should be) well secured within the Airfield Perimeter and regularly well patrolled.
Even more so in light of the recent JIA attack. So still its not completely plausible.