We've already mentioned malfunctioning parachutes and engine failures, but there is plenty of other gear that can fail while in the air. Air sportsmen rely on a lot of different types of protective and functional gear. For instance, in 2010, a 38-year veteran hang glider died after performing a loop when his glider collapsed [source: Knoll].
One common problem in several air sports is busted straps. A skydiver or hang glider may not notice the fraying on her harness, and a skydiver may not see the cut in his backpack. The aircraft are made to be lightweight, so every strap and pulley counts; failures can be disastrous. It's not just the safety straps, though -- even goggles, helmets and carabineers have the potential to break if they're not kept in good shape. If they give way, you may lose visibility or the ability to steer.
Broken landing gear can also lead to disaster. Like an engine failure, there is nothing a pilot can do but rely on his wits and hope for the best.
With any air sport, it's incredibly important to give your gear a thorough once-over before participating in the sport