Re: Air performance
 

Err, no. It's true most of the spectacular stuff had been done by 1980, but since then thrust-to-weight ratios and reliability have improved a great deal.

Re: Air performance
 

I meant on the beginning side; turbojets are TL7, not TL6, but the 3e/4e crossover happens right around then.

Re: Air performance
 

To my mind jet engines that work well enough to put into the production aeroplane are one of the signifiers of TL7.

Re: Air performance
 

I've read that the major difference between Vietnam era fighters and modern ones is the huge reduction in maintenance. My dad was a crew chief stationed in Germany around 1960 and said only once did he see the whole squadron operational. That was the Cuban missile crisis and involved ignoring redundant systems being not redundant.

Re: Air performance
 

In 3e yes (1950). In 4e not so much (1940). I'm not sure if anything major other than crude radar marks the 1940 date. IMHO when they changed the TL6 date to 1880 they went too early on that too.

Re: Air performance
 

1940 is decent, working, military radars. Primitive but useful ones date from the 30s.

As for jets, 1940 is just about the point flight-worthy jets started being produced, and the mid-point of the first turboprop's production run.

It's also the point where penicillin was shown to be producible in useful quantities, though mass production didn't start for a couple of years.

Re: Air performance
 

https://en.wikipedia.org/wiki/List_o...f_World_War_II

...has no manned jet aircraft with an "entered service" date before June 1944.

As to the first turboprop's production run......

https://en.wikipedia.org/wiki/Vickers_Viscount

....has the Vickers Viscount not even flying until 1948.

Doesn't look much like 1940 to me.

Re: Air performance
 

I was talking about the engines. You're still building TL7 tech engines even if nobody puts them in a plane. Yes, they came out a little after 1940, but it's a close enough date, IMO. If you push TL7 much later, there will be even more complaints than there already are about how radar is given as TL7, but was introduced in TL6 and so on. Yes, some things come in earlier, and some later, but not everyone seems to go with that.
Again, engine, not aeroplane, though it looks like it never entered true production.

Re: Air performance
 

No, but it does list the Heinkel He 178's first flight as 1939, and three other aircraft with first flights in 1940. This includes the Caproni Campini N.1, which was regarded as the first successful jet aircraft while the He 178 was still a secret. That none of them were adopted by any military isn't really important - the He 178, for instance, was entirely a private venture, not a military project. Also worth pointing out that the turbojet was apparently invented way back in 1930.

Since the question is when the technology is available and not when it was first used for the specific purpose of blowing people up, 1940 sounds like a "good enough" date. Jet engines were invented before the date, and jet-powered aircraft regarded as successful were flying on or before that date.

Re: Air performance
 

I tend to think of TLs as being mostly for organizing gear catalogs and then the Skills for using that gear rather than memorializing theoretical accomplishments.