Just to elaborate on the above comments.. .The airflow through the engine is part of the basic design.. .This airflow obviously takes some account for deviations. These deviations take care of engine wear and outside ambient conditions.. .When the engine is passed of the test cell there is a declared "stall margin" which is basically how much wear is allowed until the engine becomes "worn out". .There are several factors that attribute to compressor stall.. .The first is atmospherical conditions. Cross winds aggrevate the problem particularly with center engines on trijets.. .The second is general engine wear in the compressor section where the airflow becomes unstable.. .Most engines have variable inlet guide vanes and any mechanical failure will invoke compressor stall.. .The problem is that any events of compressor stall increases the wear and so lowers the stall margin.
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