The other two unknown contacts were SU-27 Flankers so naturally I assumed the third one was as well so I fired an AIM-120 before indentifying. Apparently it was a 747 with over 200 civilians onboard. Now it seems I have to prepare to face court martial. A bit of an overkill I think. Considering that the 747 was closing at alarming speed among SU-27 Flankers. Therefore not my fault.