For everyone not knowing how to make a car fly:

1 unzip the zip file

2.Backup handling.dat and vehicles.ide, and then replace the two files in the zip with the ones in your gtaiv/common/data folder

3. start gta iv, and find the fbi buffalo, or use the correct FBI car cheat.

4. you will need lot of space forward, because you cant steer, and it will take a while to start flying.

5. happy flying!

Video: http://www.youtube.com/watch?v=uGJdGkqfMlQ


EDITED LINES:
HANDLING.DAT
FBI 1550.0 7.5 85	0.0 0.0 -0.24 		0.0 5 0.22 1.0 150.0	0.25 0.65 0.7 35.0		1.35 1.10 13.5 0.15 0.48		2.0 1.2 1.2 0.13 -0.13 0.0 0.5 		1.0 1.0 0.8 1.5 	0.0 25000 		4000000		1				0


Under ; planes 	
FBI	5000.0 10.0 75 	0.0 0.0 0.0 	0.0 1 0.30 1.0 160.0	0.4 0.60 0.7 25.0		0.65 0.60 8.0 0.10 0.5 	 	0.5 0.2 0.2 0.50 -0.05 0.0 0.5			0.5 0.5 0.8 1.5 	0.0 45000 		4000000		400000			0

Under ; '$' identifies this line as flying handling data when loading

$	FBI		0.5		2.0		0.0		-0.003 	0.002	 0.10	0.03	-0.002	0.003	0.0020	0.0		0.1 	1.0	 1.0 0.0		0.01	0.5		0.5		0.5			0.5		0.5 	0.5

VEHICLES

fbi, 		fbi, 		plane, 		FBI, 		FBI, 		VEH@STD, 	VEH@STD_LO4_LO4, 	100, 	999, 		0.2622, 0.2622, 		0, 	5, 	1.0	, 0, 	-


(also forgot to remove super-strong taxt from the handling file, so its super-strong)