"vincent p. norris" wrote in message
The fuel-air mixture for a piston engine is about 14
pounds of air per pound of avgas, is it not? Would it be about the
same for jet fuel?

Jet fuel averages 6.7 pounds per gallon with more BTUs, so the
stoichiometric ratio is slightly different. Much of the air ingested by a
jet engine is used for cooling, not for burning. Do we include this air as
being ingested? Do we include the fan's cold stream as being ingested?

D.