I suppose if one has a Licentiateship in Aeronautical Engineering off the back of a service career one could also consider 'engineer' an appropriate moniker, also dictionary definition:
https://en.oxforddictionaries.com/definition/engineer
A person who designs, builds, or maintains engines, machines, or structures.
or
A person qualified in a branch of engineering, especially as a professional.
‘an aeronautical engineer’