The U.S. Marine Corps are sending at least one squadron of 10-12 MV-22 tilt rotor transports to Afghanistan this year. Some of the MV-22s will be equipped with a GAU-2B machine-gun fitted to the bottom of the aircraft. The GAU-2B is a remote control turret using a six-barrel 7.62mm machine-gun. This system has a rate of fire of 3,000 rounds per minute (50 per second), and max range of 1,500 meters. The system weighs a few hundred pounds and includes 4,000 rounds of ammo. A member of the crew uses a video game like interface to operate the gun.
This weapon is part of the Universal Turret System (UTS) for Helicopters. Plans for arming the V-22 have been discussed for nearly a decade. The original proposal was for a UTS equipped with a 12.7mm machine-gun. That has a longer range (about 2,000 meters, compared to 800), but the 7.62mm GAU-2B could lay down more bullets more quickly. Experience in Iraq and Afghanistan indicated this would be a more useful defensive measure. The UTS will be mounted on MV-22s (and SOCOM CV-22s) as needed. The machine-gun turret is mainly there for protection from local threats, not for turning the V-22 into an assault aircraft. The marines also plan to mount an M-2 12.7mm machine-gun on the rear ramp as well. Currently they sometimes use a 7.62mm machine-gun there, but the 12.7mm weapon has been successfully used on the rear ramp of large helicopters.
The marine MV-22s can carry 24 troops 700 kilometers (vertical take-off, level flight, landing, and return) at 400 kilometers an hour. The MV-22 is replacing the CH-46E helicopter, which can carry 12 troops 350 kilometers at a speed of 200 kilometers an hour. The MV-22 can carry a 10,000-pound external sling load 135 kilometers, while the CH-46E can carry 3,000 pounds only 90 kilometers.