Problem in singleplayer flight mission

[I'm a Cop, you Idiot]

hey everyone I realise this may completely be my fault and im just missing something (as usual) so dont be TOO mean if you can help it but im at the flight mission part of the game and the ship keeps going down as if its a magnet being attracted to the floor! it just floats down there no matter what I do then the ship goes insane bumping into trees! so its kind of unplayable any advice would be great so I can keep playing crysis

[IcyDoesIt]

Use your mouse and look up. There's a key for boosting your ship upward but I don't remember, maybe the space bar? Look in your controls settings.