text: provide a convenient limit 
  speed flight. 
  
  to sustained high 
  
  (5) The effect of engine overspeed or critical vi- 
  bration speed ranger is important in the service 
  life of an engine. One of the principal sources 
  of turbine loads is the centrifugal loads due to 
  rotation. Since the centrifugal loads vary as 
  the square of the rotative speed, a 5 percent 
  overspeed would produce 10.25 percent over- 
  stress (1.05*= 1.1025). The large increase in 
  stress with rorative speed could produce very 
  rapid accumulation of creep and fatigue dam- 
  age at high temperature. Repeated overspeed 
  and, hence, overstress can cause failure early 
  in the anticipated service life. 
  
  Restarting the engine in flight requires sufli- 
  cient RPM and airflow to allow stabilized op- 
  eration. Generally, the extremes of altitude 
  are most critical for attempted airstart. 
  
  (4) An increased compressor  inlet air tcmpcra- 
  
  tare can have a profound effect on the output 
  tbLrust of 2 
  in 
  figure 2.13, an increase in compressor inlet 
  temperature produces an even greater increase 
  in the compressor discharge temperature. Since 
  to 
  the turbine 
  some maximum value, any increase in com- 
  pressor discharge temperature will 
  reduce the 
  temperature change which can take place in 
  the combustion chamber. Hence, the fuel flow 
  will be limited and a reduction in thrust is 
  incurred. 