PlayStation 2
The PlayStation 2 version of "Grand Theft Auto: San Andreas" requires you to press triangle, triangle, square, circle, X, L1, L1, down and up to obtain a Hydra. When pressing down and up, use the controller's D-pad, not the analog control sticks. Upon entering the code, a Hydra will appear next to CJ.
Xbox and Xbox 360
To spawn a Hydra on the Xbox version of the game, press Y, Y, X, B, A, left trigger, left trigger, down and up. For the directional inputs, use the D-pad instead of the analog sticks. The game was also released on the Xbox 360 as a downloadable game over Xbox Live. The Xbox 360 version uses the same code. For codes that require the Xbox controller's white and black buttons, Xbox 360 users should use the left bumper for white and the right bumper for black.
PC and Mac
The PC and Mac version of "Grand Theft Auto: San Andreas" requires you to type in the code. The code won't work if you enter it on the menu or pause screens. While in-game actually playing, type "jumpjet" on your keyboard without the quotes. There's no space between the words and both uppercase and lowercase work.
Controls
The Hydra controls like a mixture between the game's helicopters and airplanes. Upon entering the Hydra, you'll be in hover mode, where you can raise or lower your altitude. For console versions, holding the right analog stick up switches to Jet mode, making the controls similar to those of the game's airplanes. PC players switch from hover and jet modes by pressing "8" on their keyboard's number pad. To switch to hover mode, console players press down on the right analog stick, while PC players press "2" on their number pad.