From PlanetSide Wiki

The Liberator is the attack gunship for all three empires. It takes a crew of three (pilot, gunner, and tailgunner). The gunner will not have access to bombs, but will have a powerful gun that can pivot in a limited arc. The pilot also has access to weapons, but are not as powerful as the gunner's.

PlanetSide 1

This bomber is a three-crew vehicle. The pilot not only flies the vehicle, but also has a fixed-forward firing 35mm heavy machinegun for strafing ground targets. The tailgunner has a highly-maneuverable 25mm machinegun to cover the rear of the aircraft. The bombardier can drop bombs of two varieties, either tankbuster (which punches and destroys armored targets) or anti-personnel where the bomb splinters into nine pieces on its way down to pattern-bomb an area with smaller, anti-infantry explosions. The bombardier has some control over the destination of the bombs and can set drag on those bombs to hit nearer or farther than the default drop position by moving the mouse back and forth along the sighting line seen from the bombardier position.

PlanetSide 2 Vehicles
Nanite Systems	Lightning • Galaxy • Liberator • Sunderer • Quad
New Conglomerate	Vanguard • Reaver
Terran Republic	Prowler • Mosquito
Vanu Sovereignty	Magrider • Scythe