Aviation incident ENG17IA028

A Bombardier CRJ700 No. 1 engine failure caused by buckling of the combustion outer liner due to fatigue cracks. The liner buckling resulted in airflow disruption and reduced engine performance. The engine fuel control unit attempted to compensate for the decrease in engine performance by increasing the fuel flow rate. The combustion liner damage and increased fuel flow led to incomplete combustion of the fuel injected into the combustion chamber. Unconsumed fuel then ignited downstream of the combustion chamber (delayed ignition) and resulted in high pressure turbine thermal damage, and the eventual separation of a high pressure turbine 2nd stage nozzle vane segment. The separated vane segment subsequently caused low pressure turbine case burn through and catastrophic impact damage to the high and low pressure turbine stages.