Prior To The Islamic Revolution, Most Of The Army's Large Air Force Fleet Was Organized By A Variety Of American Aircraft. Twenty Years Later, In The Late Sixties, The Air Force Could Use From The Political Situation Of Some Newly Independent Countries Of The Former Soviet Union Equip It’s Fleet With A Variety Of Eastern Airplanes. Now, After Four Decades Of Western Birds Activity And More Than Two Decades Of Service Life To Eastern Aircraft An In-Depth Review And Comparison Of Their Operational Performance Together Seems Essential. In Order To Collect The Data Of The Present Study Documents And Questionnaires Were Used. Statistical Community Of All Commanders, Deputy Headquarters Staff And Support And Command Staff, Headquarters Staff And R&D Or-ganization And All Pilot And Technical Staff Of IRIAF Bases That After Sampling The Sample Population Was Reduced To 68 Individuals. The Method Of Analysis Is Qualita-tive Information And Is Performed With The Help Of Content Analysis Statistical Analysis Was Performed With The Help Of TOPSIS Software And The Information Obtained From The Sample Population Is Generalized To The Statistical Population This Study Investi-gates Compares The Operational Comparative Performance In Three Dimensions Of Op-erations System, Training And Support System And Training System Of Western And Eastern Aircraf. According To The Research Results, The Operational Performance Of The Existing IRIAF Western Fighter Aircraft In Different Aspects Such As Operation System, Training And Support System And
Training System Compared To The Existing Eastern Fighter Aircrafts. Are Superior.