1.   Investigators discovered a malfunction in the propeller pitch control and a worn part in a propeller control system on the left engine.

2.   Both companies design and manufacture commercial propeller systems for aircraft.

3.   Future tests of the airplane will use versions with folding wings and, eventually, its own propeller propulsion system.

4.   Propeller systems overhaul and repair work now done in East Windsor will move to Long Beach, Calif., and Maastricht, the Netherlands.