I found the airport by accident doing a jet ski circumnavigation of the water line. I am pretty sure I entered from actual runways, copped a 3 star rating straight away but saw a lot of small jets attempting my get away.
Gotta say that GTA V is probably one of the most fun and polished open world games I have ever played. So much to do and explore.
Found a cool way to get free guns & ammo, follow the cops to shoot outs and just collect em off the dead cops or baddies
Need to confirm it but I think the parachute you pick up at the top of the cable car stays with you if you dont use it up there. I went and grabbed it, fell off the cliff attempting a stupidly long dirt bike jump, spawned back at the hospital with it still in my inv (visible in the lower right corner of the weapon wheel.) So I went and base jumped off a bridge, only to pull the shoot way to late and come face to face with some concrete