Oh, shit. That's the worst and most boring mission ever! And, you can google it to find Mission Faqs. It depends on how you set up your controls on your PC. Check your Control Settings, and maybe you could find out. Mostly everybodys Controls are different.
Anyway, good luck buddy.
( Oh, and I'm not sure that I remember but I think you control it like this To move the helicopter around press the ^ v > < keys - Going Forward: Press the 6 all the way on the right of your keyboard ) Those were my controls, maybe you have the same also.