i invented the helicopter method :) vcn roof has one at the very start of the game, and when you get 15000 you can buy the apartment near hymen stadium and get a free heli on the roof :)
when you start a new game if you need a helicopter before the first mission, simply get to the second island by jumping on a boat or walking under the bridge near the movie studio up north :) also SEAWAYS will allow your car to drive on water and you can just get over there and steal the VCN heli on the roof of the news station :)
easy heli pc controls: kinda like WASD, bind the IJKL as your pitch roll yaw controls and you can use WASD IJKL to control the heli easy :) i dont have a numpad on my laptop
Old trick. Good if you can't for the love of god complete it the intended way. Except it's less fun and you'll skip some stunt jumps that are required for 100% completion.