engine must be controlled and regulated to 
prevent any one or combination of the follow- 
ing items: 
(1) compressor stall or surge 
(2) excessive turbine inlet temperature 
(3) excessively rich fuel-air ratio which 
may not sustain combustion 
Generally, the stall-surge and turbine tem- 
perature limits predominate to form an ac- 
celeration fuel flow boundary typified by curve 
121