"John" wrote in message
...
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It's supposed to be fairly stable because the thrust reaction point is
well above the CG, so there is a strong pendulum effect. They claim it's
better than a helicopter.

An often made, completely wrong assumption - "pendulm effect" - ain't no
such thing for an object in free flight.

Early rocket experimenters often attempted use "tractor" engines assuming
that it would provide stability - Dr. Robert Goddard's first liquid rocket
is an example. It didn't take them long to figure out that they were wrong.

--
Geoff
The Sea Hawk at Wow Way d0t Com
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