Luckily for him, Brightblaze is second. She dives, gets herself under him - and finds out that dragons are heavy, even pony-sized ones, and she needs all four boots to achieve stable lift and get him safely to the ground. Which means not a hoof to spare to hang onto him, which means some very delicate balancing that's going to take time, which means she'd better hope Streak can take care of the three non-fliers by herself.