GAU-19 three-barrel Gatling gun mounted below the nose was studied. BAE Systems developed a belly-mounted, remotely operated gun turret system, the Interim Defense Weapon System (IDWS); it is remotely operated by a gunner, targets are acquired via a separate pod using color television and forward looking infrared imagery. The IDWS was installed on half of the V-22s deployed to Afghanistan in 2009; it found limited use because of its weight and restrictive rules of engagement. There were 32 IDWSs available to the USMC in June 2012; V-22s often flew without it as the added weight reduced cargo capacity. The V-22's speed allows it to outrun conventional support helicopters, thus a self-defense capability was required on long-range independent operations. The infrared gun camera proved useful for reconnaissance and surveillance. Other weapons were studied to provide all-quadrant fire, including nose guns, door guns, and non-lethal countermeasures to work with the current ramp-mounted machine gun and the IDWS. In 2014, the USMC studied new weapons with "all-axis, stand-off, and precision capabilities", akin to the AGM-114 Hellfire, AGM-176 Griffin, Joint Air-to-Ground Missile, and GBU-53/B SDB II. In November 2014, Bell Boeing conducted self-funded weapons tests, equipping a V-22 with a pylon on the front fuselage and replacing the AN/AAQ-27A EO camera with an L-3 Wescam MX-15 sensor/laser designator. 26 unguided Hydra 70 rockets, two guided APKWS rockets, and two Griffin B missiles were fired over five flights. The USMC and USAF sought a traversable nose-mounted weapon connected to a helmet-mounted sight; recoil complicated integrating a forward-facing gun. A pylon could carry of munitions. However, by 2019, the USMC opted for IDWS upgrades over adopting new weapons. Refueling capability Boeing is developing a roll-on/roll-off aerial refueling kit, which would give the V-22 the ability to refuel other aircraft. Having an aerial refueling capability that can be based on Wasp-class amphibious assault ships would increase the F-35B's strike power, removing reliance on refueling assets solely based on large s or land bases. The roll-on/roll-off kit can also be applicable to intelligence, surveillance and reconnaissance (ISR) functions. Boeing funded a non-functional demonstration on a VMX-22 aircraft; a prototype kit was successfully tested with an F/A-18 on 5 September 2013. The high-speed version of the hose/drogue refueling system can be deployed at and function at up to . A mix of tanks and a roll-on/roll-off bladder house up to of fuel. The ramp must open to extend the