By Stephanie Apstein The U.S. took home Olympic gold in the mixed team aerials, but it didn’t come without addressing frights that may seem contrary to the nature of the sport. YANQING, China — They take off at 40 miles per hour, 200 feet above the ground, headed for a 71-degree ramp, then explode off it, flipping through the air a maximum of three times because any more could be fatal. Aerials skiing is probably the Olympic sport with the fewest moms able to watch in real time. But for its participants, the jumps are fun. The hard part might come as a surprise: Many of them are petrified of h…