I assume most of you have gone to the airport and driven next to the Jumbo Jets that look like 747's and then said to your self (awwe man!) when you realize you can't get in them, well you can! well, not those parked ones at least, but you can fly the ones that land, here's how for those who didn't already know;
Go to the airport (Owning a hanger will stop police gunning you down)
Wait for the 747 type to land (Haven't tried it with the ones about to take off)
It will proceed down to the end of the runway once landed, follow it and wait for it to come to a stop at "Hanger 1" (It'll shut it's engines off)
Simply walk up to the Door, hit Triangle or Y, and vuala!
Just thought I'd make this for those thinking they're un-flyable, enjoy!
(Note I refereed to them as 747 type because they don't have a name, they're simply called "Jet" on the vehicle name thing that pops up)