{HEAD ~ The first wall} is located near {TAIL ~ the combustion chamber} and flexes in response to varying combustion chamber pressure 
is located near
{ HEAD ~ The first wall } is located near { TAIL ~ the combustion chamber } and flexes in response to varying combustion chamber pressure
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH