1.   And a Pentagon report released last month recommended further testing to diagnose vortex ring state.

2.   Brow descended too fast, with too little airspeed, sending his aircraft into a condition called vortex ring state, the report said.

3.   He is also ordering further tests into vortex ring state.

4.   In the Arizona accident, the Marines concluded that one factor was pilot error in dealing with a vortex ring state.

5.   Investigators determined that the crash had been caused by vortex ring state, an aerodynamic occurrence in which a rotorcraft rapidly descending into its own turbulent wake loses lift.

6.   Panel members chastised Osprey managers for not producing manuals with clear descriptions of vortex ring state, and called for cockpit lights that could warn of the condition.

7.   Pentagon investigators have found that program officials canceled tests into vortex ring state to meet deadlines and reduce costs.

8.   That configuration caused the Osprey to flip over when it entered vortex ring state, experts have said.

9.   The lawyers, citing Pentagon reports, also said that the flight simulators used to train Osprey pilots were not programmed to simulate vortex ring state.

10.   The report does not assert that the Osprey is absolutely safe or that the manufacturers, Boeing and Bell Textron, fully understand the vortex ring state.