i had the same problem, i never thought i would be able to do it... until i did.
for me i was incorrectly using the nozzle, was basically trying to eyeball it in at 80 degrees... then i started using the HUD indicator and dialed in at 82 degrees and whamm i took off vertically!
as others have mentioned make sure youre light w no weapons and make it easy ion yourself in the begging, then work your way up by adding stores.
good luck!!!