Is LHV or HHV used for calculating the thrust of a jet engine? Lower and Higher Heat Values (LHV or HHV) seem to have multiple definitions based on things I can't figure out.

What I want to know is, which one is appropriate to use for calculating the thrust from a jet engine? I'm thinking of large commercial turbofan engines like on the 747 or A380.

Also, since water vapor seems to have something to do with it, what about jet engines that run on hydrogen like the experimental Tu-155? Should we use LHV or HHV to calculate thrust in those engines?
The difference between both values is the energy set free when the water created by the combustion process condenses. Use the lower heat value for jet engine calculations. The water in a jet engine leaves it as vapor, and the vaporisation heat is lost for propulsion.