The real difficulty, not explored in this disassembly, is that the game has semi-realistic physics! My older brother was in flight school at the time and was able to easily land the plane and taught me how to do it.
As the article states, "Altitude and speed are both controlled by throttle input and pitch angle". So you can't just hit the engines or air brakes button to change your speed. If you lower the nose of the plane, you'll speed up and vice versa! So you have to carefully juggle your speed and altitude by altering both your pitch and your engines/air brakes.
My brother taught me that my speed wouldn't reduce if I'm nosediving, so raise the nose a little while opening my air brakes for a quick reduction in speed and then level out to maintain altitude. The game actually models this somewhat accurately!