drop tanks can be mounted on the two inboard under-wing hardpoints. The fuel system is compatible with in-flight refueling (IFR), allowing tanker aircraft to refuel inflight, and increasing its range and loitering time significantly. All production aircraft for the PAF are to be fitted with IFR probes. In June 2013, PAF Air Chief Marshal Tahir Rafique Butt said ground tests on the JF-17's refueling probes had been successfully completed and the first mid-air refuelling operations would commence that summer. Armaments The JF-17 can be armed with up to of air-to-air and air-to-ground weaponry, and other equipment mounted externally on the aircraft's seven hardpoints. One hardpoint is located under the fuselage between the main landing gear, two are underneath each wing, and one is at each wing-tip. All seven hardpoints communicate via a MIL-STD-1760 data-bus architecture with the Stores Management System, which is stated to be capable of integration with weaponry of any origin. Internal armament comprises one GSh-23-2 twin-barrel cannon mounted under the port side air intake, which can be replaced with a GSh-30-2 twin-barrel cannon. The wing-tip hard-points are typically occupied by short range infra-red homing AAMs. Many combinations of ordnance and equipment such as targeting pods can be carried on the under-wing and under-fuselage hard-points. Underwing hard-points can be fitted with multiple ejector racks, allowing each hard-point to carry two unguided bombs or LGBsMk.82 or GBU-12. It is unknown whether multiple ejector racks can be used for ordnance such as beyond visual range (BVR) AAMs. Active radar homing BVR AAMs can be integrated with the radar and data-link for mid-course updates. The Chinese PL-12/SD-10 is expected to be the aircraft's primary BVR air-to-air weapon, although this may change if radars of other origin are fitted. Short range, infra-red homing missiles include the Chinese PL-5E and PL-9C. The PAF is also seeking to arm the JF-17 with a fifth generation close-combat missile such as the PL10E IRIS-T or A-Darter. These will be integrated with the HMS/D and the radar for targeting. Unguided air-to-ground weaponry includes rocket pods, gravity bombs and Matra Durandal anti-runway munitions. Precision-guided munitions such as LGBs and satellite-guided bombs are also compatible with the JF-17, as are other guided weapons such as anti-ship missiles and anti-radiation missiles. Pakistan planned to bring the Brazilian MAR-1 anti-radiation missile into service on its JF-17 fleet in 2014. Operational history Pakistan Small batch production of the single-seat, single-engine JF-17s began