ANALYSIS OF CAUSE OF FAILURE OF VIPER 633-41 ENGINE OF J-22 ORAO AIRCRAFT DUE TO IRREGULAR REGULATION OF BASIC OPERATING PARAMETERS OF THE ENGINE IN SERVICE, AND DEGRADATION OF PHYSICAL AND MECHANICAL CHARACTERISTICS OF TURBOJET ENGINE RUBBER COMPONENTS

EMIL BANJAC

"Orao" a.d, Bijeljina, emilbanjac@yahoo.com; emil.banjac@orao.aero

Abstract: During the flight of the J-22 aircraft, No. 25207,on VIPER 633-41engine, ser. No. 6332180Y occurred unstable operation and flame in the exhaust pipe due to the rapid gunning of the engine from the regime 75% to 100% revolutions per minute (RPM), in the stage of the sharp forced turn. After moving the throttle to the position of RPM    descrease, the engine parameteres stabilized and did not exceed the permissable limits.Repeated gunning of the engine resulted in repeated occurrence of irregular operation of the engine. Based on the technical finding of the failure, additional inspections and testings of the engine were performed at the test cell in order to determine the cause of failure and to define a proposal of actions for service of VIPER 632/633 engine. The paper „Analysis of cause of failure of VIPER 633-41 engine of J-22 ORAO aircraft due to irregular regulation of basic operating parameters of the engine in service, and degradation of physical and mechanical characteristics of turbojet engine rubber components“ shows a detailed algorithm for determining causes of the failure. Based on the carried out inspections and testings, actions for increasing safety of operating use of turbojet VIPER 632/633 engines were defined.