Helicopter crash: Four dead US air crew to be recovered 9 January 2014 Last updated at 03:34 The bodies of four American servicemen killed when their helicopter came down during a training exercise on the north Norfolk coast are due to be recovered. Capt Christopher Stover, Capt Sean Ruane, Technical Sgt Dale Mathews and Staff Sgt Afton Ponce died in the crash in Cley next the Sea. Tributes have been paid to Capt Ruane, who leaves a wife Rachel and their young son Liam. Air accident, RAF and US investigators have spent the last two days at the scene of the crash. The inquiry is being hampered because the helicopter was carrying munitions, meaning that ordnance has been scattered around the site, investigators said. The HH-60G Pave Hawk, a version of the US Army's Black Hawk helicopter, is used by the US Air Force for combat search and rescue, mainly to recover downed aircrew or other isolated personnel in war zones. The helicopter, made by Sikorsky, has been used in numerous military missions, in Iraq and Afghanistan, as well as civilian rescue operations after disasters like the 2004 Boxing Day tsunami in Sri Lanka and Hurricane Katrina in the US in 2005. The Pave Hawk, which came into service in 1981, has a four-man crew and can carry up to 12 troops. RAF Lakenheath, where US Airforce 48th Fighter Wing is based, said that Captains Stover and Ruane were pilots, while Tech Sgt Mathews and SSgt Ponce were acting as special mission aviators.