Off topic: The very first assignment in this game is called “oil tank holiday”: fly the chopper to unguarded oil tanks, shoot and watch them burn, and then fly home. No enemies. Just learn to fly and shoot.
I apply this in testing code. After you write some code, try to think of the absolute minimal test to prove that your code does anything at all without crashing. These are my “oil tank holiday” tests. It is always humbling to see those fail.
What I'm hearing is that the smoke in smoke tests comes from the oil tanks!