the Shadow had achieved 750,000 flight hours during more than 173,000 missions. More than 900,000 flight hours had been logged by Shadow UAVs by the end of June 2014. The Shadow did not see service in the Afghanistan campaign of 2001–2002, but it did fly operational missions in support of Operation Iraqi Freedom. The operating conditions in Iraq proved hard on the UAVs, with heat and sand leading to engine failures, resulting in a high-priority effort to find fixes with changes in system technology and operating procedures. Shadow UAS have since flown more than 600,000 combat hours in support of the Wars in Iraq and Afghanistan. In 2007, the United States Marine Corps began to transition from the RQ-2 Pioneer to the RQ-7 Shadow. VMU-1, VMU-2 completed their transition from the RQ-2 to the RQ-7 and ScanEagle while VMU-3 and VMU-4 were activated as Shadow and ScanEagle elements. VMU-3 was activated on 12 September 2008 and VMU-4 conducted its inaugural flight on 28 September 2010 in Yuma, Arizona. In October 2007, VMU-1 became the first Marine Corps squadron to see combat in Iraq. VMU-2 deployed a Shadow detachment to Afghanistan in 2009, with VMU-3 following in January 2010. The Navy provided personnel for four Shadow platoons in support of army brigades deployed in Iraq. The first two platoons returned from 6-month tours in Iraq in January and February 2008. The Navy personnel went through the Army's training program at Fort Huachuca, Arizona. The U.S. Army is implementing a plan to reform its aerial scout capabilities by scrapping its fleet of OH-58 Kiowa helicopters from 2015 to 2019 and replacing them with AH-64 Apache attack helicopters teamed with Shadow and MQ-1C Gray Eagle UAVs. Using unmanned assets to scout ahead would put the pilots of manned aircraft out of reach of potential harm. Reformed combat aviation brigades (CAB) would consist of a battalion of 24 Apaches for attack missions and an armed reconnaissance squadron of another 24 Apaches teamed with three Shadow platoons totaling 12 RQ-7s overall; it would also include a Gray Eagle company. The manned-unmanned teaming of Apaches and Unmanned Aircraft (UA) can meet 80 percent of aerial scout requirements. On 16 March 2015, the 1st Battalion, 501st Aviation Regiment was reflagged the 3rd Squadron, 6th Cavalry Regiment, making it the first of 10 Apache battalions to be converted to a heavy attack reconnaissance squadron by eliminating the Kiowa