Why ever not,
Ninthace ? Even the Russians were at it in the 90s too…
https://www.youtube.com/watch?v=Tx5AmHxoQJY
https://en.wikipedia.org/wiki/Thermoplan
The Thermo-Skyship also predicted a 600-900 mile range at over 100kts in its original envisaged configuration in the magazines of the day. it could also quite easily go in and out under cover of darkness. It does have a large heat signature though, but in those days the average layman didn’t have that sort of tech to see it at night without lights.
As for silent turbojets - wouldn’t the Hunter (or Harrier) have created a bit of racket, or are you suggesting they were glider variants?
Finally, the Russians also, according to this article:
https://lynceans.org/wp-content/uplo...-converted.pdf were developing a nuke powered thermoplane that could fly for 8 years!
