[quote=@Voltus_Ventus]
<Snipped quote by Willy Vereb>

There you go, lack of a previous conflict would mean that no one knows the significance of air superiority and thus jet engines would have been neglected.
[/quote]That's what I think, too. Lack of conflict means that nations don't compete with each other so much in speed.
Albeit both my nation and the Avians are quite developed in terms of air force and try to make the best of them.
My elves also have sensitive ears and likeness for speed.
After some research I deducted they'd mostly use ducted turboprop engines and the difference between turboprop and turbofan (AKA jets) is a thin one.
I keep them having turboprops for now but the breakthrough in jets is within the doorstep.
I'll reason some of the delay with the fact supersonic fans (something which happens for near-every turbofan engine) would produce more noise which is exactly what the elves don't want.