Well I have had first flight.
I set the throttles to idle, hit the starter for both engines, waited for them to spin up and ignite. Pushed the throttles through the stops to full afterburner. Waited until it hit 100 knots. Put a little back pressure on the stick.... the nose rotated up, and the aircraft flew cleanly up to 500 feet.
Then the nose began to drop, the airspeed bled off and the stall warning kicked in. I cleaned the aircraft and centered the stick. No good, piled into the deck a few seconds later.
It was like getting all seven numbers in the UK national lottery and knowing I had a share in £15 million, only to then find out 15 million other people also had all seven numbers.
So I wrote some code to allow scripted testing of the various systems and ran a test that generates a CSV file with engine thrust output as a function of speed and altitude
My thrust calculation is completely wrong.
At sea level the engines produce hardly any thrust, the thrust increases as the altitude increases until it reaches about 15,000 feet. Then it levels off.
Oh well, at least I am now in the debugging stage rather than writing code I cannot test.