The Andromeda (large 4-engine transport plane) does not exist as a controllable vehicle in GTA: San Andreas on PS2 (or any platform).
On PC, CLEO mods or SAMP/MTA scripts make Andromada flyable with custom handling.
On PS2: Only via Action Replay / CodeBreaker / GameShark master code + "Fly Andromada" code. No in-game method.