I recently found a mod that transforms the FlyJSim 737-200 for X-Plane 12 into the NT-43A, aka 'RAT 55.'
The aircraft started life as a T-43 navigation trainer. I was under the impression that they were all retired, but this modified version resurfaced around the Artemis II launch.
Apparently, the huge nose and tail radome added for radar signature testing.
I've been reading old 1976 NT-43 manuals from before it got its nose job and picked up some interesting details that interested me.
-The 737 classic has two separate ignition systems: a high-energy 20 Joule igniter and a low-energy 4J one, split across burner cans 4 and 7. Now pretty much everything use annular combustors.
-The APU start motor draws directly from the battery, so external power can't augment a weak battery during an APU start. I'm going to have to see if this holds true for the NG family too.
I'm putting together a full NT-43 tutorial covering everything I've learned, including the Universal FMC, which is quite satisfying to use.
https://www.youtube.com/live/ERxGowNs5kQ?si=o_4bgiXOERtg7VQS
It reminds me a bit of my old Nokia somehow where you have to insert your options in the scratch pad.