That has crossed my mind, too. If the aircraft was flying at 35K+ feet I don’t know how large the EMP would spread.
Virtually none. It would need to be well over 100k feet to produce any. It would be useful to get an airburst going at 3k-5k feet or whatever though. And of course as a ramming jet. Or bio/chem but that would take a lot of modification that I doubt any smaller group would be able to do.
Do we have proof EMP’s work or exist? If so why didn’t we use in our Afganistan or Iraq?