can turn it into a plane and glide it down, just like a C-130." A complete loss of power requires both engines to fail, as one engine can power both proprotors via interconnected drive shafts. Though vortex ring state (VRS) contributed to a deadly V-22 accident, flight testing found it to be less susceptible to VRS than conventional helicopters. A GAO report stated that the V-22 is "less forgiving than conventional helicopters" during VRS. Several test flights to explore VRS characteristics were canceled. The USMC trains pilots in the recognition of and recovery from VRS, and has instituted operational envelope limits and instrumentation to help avoid VRS conditions. Production On 28 September 2005, the Pentagon formally approved full-rate production, increasing from 11 V-22s per year to between 24 and 48 per year by 2012. Of the 458 total planned, 360 are for the USMC, 50 for the USAF, and 48 for the Navy at an average cost of $110 million per aircraft, including development costs. The V-22 had an incremental flyaway cost of $67 million per aircraft in 2008, The Navy had hoped to shave about $10 million off that cost via a five-year production contract in 2013. Each CV-22 cost $73 million in the FY 2014 budget. On 15 April 2010, the Naval Air Systems Command awarded Bell Boeing a $42.1 million contract to design an integrated processor in response to avionics obsolescence and add new network capabilities. By 2014, Raytheon began providing an avionics upgrade that includes situational awareness and blue force tracking. In 2009, a contract for Block C upgrades was awarded to Bell Boeing. In February 2012, the USMC received the first V-22C, featuring a new radar, additional mission management and electronic warfare equipment. In 2015, options for upgrading all aircraft to the V-22C standard were examined. On 12 June 2013, the U.S. DoD awarded a $4.9 billion contract for 99 V-22s in production Lots 17 and 18, including 92 MV-22s for the USMC, for completion in September 2019. A provision gives NAVAIR the option to order 23 more Ospreys. As of June 2013, the combined value of all contracts placed totaled $6.5 billion. In 2013, Bell laid off production staff following the US's order being cut to about half of the planned number. Production rate went from 40 in 2012 to 22 planned for 2015. Manufacturing robots have replaced older automated machines for increased accuracy