What's Wrong with the Osprey?
There have been several recent crashes of Osprey aircraft, many of which have resulted in the deaths of the crew and passengers. The cause of each crash has been or is being investigated. A couple of theories have been set forth to explain these crashes, including pilot error, defective computer software and a condition called vortex-ring effect or power settling. Power settling can be caused by tail winds upon landing, and may occur when the Osprey descends too rapidly. Here's what happens:
  1. Normally, the rotors have a downward air flow upon descent.
  2. If the rate of descent is too rapid, an upward vortex can form on one of the rotors.
  3. The upward vortex on one rotor combines with the downward vortex on the other, flipping the plane nose-down.
  4. The plane loses lift faster than the pilots and engines can respond, and crashes.
As of April 2001, the Osprey fleet has been grounded pending full investigation. The future of the program remains uncertain.