The routine at 204 may include adjusting {TAIL ~ the second turbine} to increase/decrease {HEAD ~ expansion} across the second turbine in response to a request for increased/decreased, respectively, engine output 
The routine at 204 may include adjusting { TAIL ~ the second turbine } to increase / decrease { HEAD ~ expansion } across the second turbine in response to a request for increased / decreased , respectively , engine output
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH