Composite FX reports on their Facebook page that John Uptigrove, designer of the Mosquito helicopter, has passed in an accident. My condolences to the family of such an innovative man, he will be missed.
John was the son of two missionaries in India. He was a dedicated Christian and had no problems saying so. He died doing what he loved. I pray that unending peace be with his wife and two kids in this tough time.
Uptigrove died in a similar way to Helicycle designer B.J. Schramm by flying over a river but few details are out yet about John's accident. Some have suggested a possible wire strike but time will tell.
I met John Uptigrove a number of years ago when I received a telephone call from him wanting to know why the rotor of a helicopter he was building flopped over to one side when he tried to run it up. He explained that he had copied the rotorhead of an early Rotorway.
The Rotorway used a variant of the Bell-47 rotor system wherein the rotor hub is mounted on a universal joint and cyclic pitch is forced to occur about a pair of pivots of the “U” joint.
I asked John if he’d omitted the link that locks the feathering bearings together. Turned out that he had.
John Uptigrove was one of the very few people in the hobycopter business who was a real rather than make believe engineer but everyone has a learning curve.
the attachment is a diagrammatic drawing of the Bell-47 cyclic system.