called high density altitude, which actually means hotter, thinner air, giving the pilot less lift and less power. >> i had to take certain steps, make certain changes to my routine. >> dennis calculates the changes he'll make and at first, everything goes smoothly. >> the standard display routine commences with a pirouette on the left front skids, rotating the helicopter. >> i got my camera out to take footage of his performance. i was excited about capturing it on camera. >> i turned to 300 feet, then a backflip away from the crowd to get distance from the crowd to commence the run-in for the opening maneuver which is a loop. >> so far, the impressive routine seems flawless. everything looked normal. >> it's very rare to see a helicopter pilot be able to do maneuvers like that. >> i never thought it was going wrong. >> but then, coming out of the