text: If an excessive pressure rise is required 
  through the compressor, stall may occur with 
  the attendant breakdown of stable, steady flow 
  through the compressor. As stall occurs, the 
  pressure rise drops and the compressor does not 
  furnish discharge at a pressure equal to the 
  combustion chamber pressure. As a result, a 
  flow reversal or backfire takes place. 
  If the 
  the indica- 
  stall is transient and intermittent, 
  “bang” as back- 
  tion will be the intermittent 
  fire and flow reversal take place. 
  If the stall 
  develops and becomes steady, strong vibration 
  and a loud (and possibly expensive) roar 
  develops from the continuous flow reversal. 
  The increase in compressor power required 
  tends to reduce RPM and the reduced airflow 
  and increased fuel flow cause rapid, immediate 
  rise in exhaust gas temperature. The pos- 
  sibility of damage is immediate with the steady 
  stall and recovery must be accomplished 
  quickly by reducing throttle setting, lowering 
  the airplane angle of attack, and increasing 
  airspeed. Generally, the compressor stall is 
  caused by one or a combination of the fol- 
  lowing items: 
  
  (ti) A malfunctioning fuel control or gov- 
  erning apparatus is a common cause. Proper 
  maintenance and adjustment is a necessity for 
  is 
  stall-free operation. The malfunctioning 
  engine 
  most usually 
  acceleration. 