Impact of Soft Errors in a Jet Engine Controller
Paper in proceedings, 2012
We present an experimental study in which we investigate the impact of particle induced soft errors occurring in the microprocessor of an experimental FADEC system. The study focuses on the impact of single bit faults in the instruction set architecture (ISA) registers. For such faults, we investigate the effectiveness of the error detection mechanisms included in the FADEC system, and determine the consequences of errors that escape detection. To this end, we injected single bit faults in the ISA registers of a Freescale MC68340 microprocessor during execution of a prototype jet engine control program. Utilizing both random fault injection and partially exhaustive injections, we conducted six fault injection campaigns comprising in total more than 7000 injected faults. Twenty-three percent of the injected faults were effective, i.e., they affected the outputs of the control program. Of these, the system detected 91%. Of the 9 % that escaped detection, 7% caused a minor deviation in engine thrust that would be harmless to flight safety, while 2% caused severe or potentially catastrophic changes in engine thrust.