I play GTA 4 on a XBOX 360 console.
About one year ago I stopped completing the above mission because after flying off the bike onto the helicopter Niko was unable to climb in.
Now I resumed the game trying to complete it; despite my frantic pushing on the A button nothing has changed; after few seconds Niko falls into the water.
Now I ask whether someone, working on the same platform (XBOX 360), has succeeded in overcoming the impasse and obviously how he did.
Thanks in advance to the helper.