Powerplant Reliability Issues and Wear Monitoring in Aircraft Piston Engines. Part II: Engine Diagnostic

Abstract

This paper introduces a method to efficiently monitor the status of a piston engine during flight. ECUs (Electronic Control Units) make it possible to fly safely without emergencies or urgencies with random electronic failures of components and connections. The same can be easily done on older engines by adding a reliable digital monitoring system and an automated calibration of the carburetors. In fact, their reliability is several order of magnitude inferior to modern turboshafts. In modern engines with FADEC (Full Authority Digital Electronic Control) as the “on” button is pressed the sensors and actuators are checked. The CPUs will then run start-up during the cranking phase (engine running without ignition). If everything is all right, then the engine starts and the post start checks are also performed. During flight, the ECU checks CPUs, sensors and actuators. Therefore, the electronic system can be monitored with high reliability without much effort. The sensors may crosscheck the engine situation and may output very reliable early diagnosis of incoming failures. Statistical data on spare parts are invaluable for monitoring application, signaling weak or not-lasting components and failure modes. This is another advantage of automotive piston engines conversions to aircraft use.