How do you pass the helicopter mission on gta4?

Answer 1

You do not say which of the helicopter missions in GTA IV. But, if it is of any help:

All of the helicopter missions on GTA IV are helped enormously by helicopter flying practice. It is worth jacking one of the Maverick helicopters from Helitours in Algonquin and practising taking off, flying, and landing, regularly, until you are able to do this easily. You can then approach the chopper missions with more "flying" expertise.