But the remotely operated turret guns, designed to give the aircraft a more effective way to neutralize enemy threats, has gone widely unused because Marines and their leaders believe its drawbacks frequently outweigh its benefits.
Marine Medium Tiltrotor Squadron 261, out of Marine Corps Air Station New River, N.C., has five belly gun systems with it downrange, but it is seen as heavy and difficult to use. A Marine crew chief, frequently a gunnery sergeant, operates the system from the inside using a controller and can rotate the gun 360 degrees. He acquires targets using a monitor that is fed color images from a forward-looking infrared sensor.
Marines, however, acknowledged that operating the belly gun system can cause nausea for the crew chief using it, since he must stare at the screen while the aircraft maneuvers.
Another major drawback is that the belly gun is heavy, weighing in at 800 pounds. That dramatically affects how much cargo or troops an MV-22 can carry. The Osprey can carry about 12,000 pounds of fuel, personnel and equipment in 70-degree weather, but when the temperature exceeds 107 degrees — as the summer weather in southern Afghanistan does regularly — the Osprey’s capacity drops to between 8,000 and 8,500 pounds, Woods said.
Lt. Col. Ivan Thomas, VMM-261’s commander, has told the media that the rules of engagement pose another challenge. Last summer, Army Gen. Stanley McChrystal, then the commander of NATO forces in Afghanistan, issued new guidelines directing commanders to restrict air-to-ground munitions and direct fire against residences. Thomas has said the risk of civilian casualties often is just too great to use the weapon system.
The belly gun was pushed out quickly based on an urgent need from the field for an all-quadrant defensive weapon system, but the mission-based system was never meant to be a permanent solution, Welding said.
Despite its drawbacks, pilots with VMM-261 say the 7.62mm weapon, formally known as the Interim Defense Weapon System, has impressed them with its accuracy and ability to lock onto targets while Ospreys are in flight. They are more comfortable though, using the Osprey’s tilt-rotor design to zip in and out of combat situations quickly.
Source: Dan Lamothe for Marine Corps Times.