It feels the devs are making an in-joke here; the Lightnings are stealth, b/c they never show up in-game when it matters 
I did get a single Lightning in a previous session to go for a test drive, but that was around turn 450 or so, after capturing enough Alum and Oil to do so. I don't think it was particularly impressive for its hurdles.
For anyone that wants to seriously propose ideas, I also have the following requirements:
- This needs to work on Nation difficulty or higher and other standard settings.
- This needs to work w/out trading. I need to be able to build the Lightnings during peace time and in war time against anyone after all!
I'm doing this to try and learn more about the air model in HK, but also I'm trying to find the value in adopting the American culture. Their LT seems to be at odds with their Expansionist affinity, and also does not seem to scale well at all. The Defense Agency is poop; it's Garrison-like but it doesn't take on Garrison bonuses, and if I want lots of Influence, Grand Teahouses about 2 eras back do a way better job. This leaves Lightnings, but if I can't get any meaningful use out of Lightnings before the session ends, then I'm just going to pretend that the Americans don't exist as a culture choice.
So far I think I like Civ6's air model more than HK's, which is funny b/c I lament the way air units currently work in Civ games. In case y'all aren't familiar, I tend to gripe over the air models in Civ6 and Civ5. I got into Civ b/c of Airships from Empires of the Smoky Skies, I really like hover units in CivBE, and I like Civ2's air model just fine. The Civ5 air model is super boring; air units are low interaction and just point-and-click, no tactics and no meaningful positioning. This improved a bit in Civ6; positioning for Air Fighters mattered, even though I wish they would at least exert ZoC. From what I've experienced, the HK air model is basically Civ5's point-and-click snorefest, and I'm hoping to see something more interesting soon.

I did get a single Lightning in a previous session to go for a test drive, but that was around turn 450 or so, after capturing enough Alum and Oil to do so. I don't think it was particularly impressive for its hurdles.
For anyone that wants to seriously propose ideas, I also have the following requirements:
- This needs to work on Nation difficulty or higher and other standard settings.
- This needs to work w/out trading. I need to be able to build the Lightnings during peace time and in war time against anyone after all!
I'm doing this to try and learn more about the air model in HK, but also I'm trying to find the value in adopting the American culture. Their LT seems to be at odds with their Expansionist affinity, and also does not seem to scale well at all. The Defense Agency is poop; it's Garrison-like but it doesn't take on Garrison bonuses, and if I want lots of Influence, Grand Teahouses about 2 eras back do a way better job. This leaves Lightnings, but if I can't get any meaningful use out of Lightnings before the session ends, then I'm just going to pretend that the Americans don't exist as a culture choice.
So far I think I like Civ6's air model more than HK's, which is funny b/c I lament the way air units currently work in Civ games. In case y'all aren't familiar, I tend to gripe over the air models in Civ6 and Civ5. I got into Civ b/c of Airships from Empires of the Smoky Skies, I really like hover units in CivBE, and I like Civ2's air model just fine. The Civ5 air model is super boring; air units are low interaction and just point-and-click, no tactics and no meaningful positioning. This improved a bit in Civ6; positioning for Air Fighters mattered, even though I wish they would at least exert ZoC. From what I've experienced, the HK air model is basically Civ5's point-and-click snorefest, and I'm hoping to see something more interesting soon.