Originally Posted by
heli1
Sikorsky would have had to fly straight and level and with the aft propulser free wheeling to qualify for the helicopter speed record attempt. Otherwise Bell could have claimed it years ago with their modified UH-1 and its prodded jet engines.
IIRC, the Bell 533 often flew with a wing, which I believe would disqualify it, the rotor not being the only lift surface. More importantly, the podded jets were not integral to the rotorcraft's lift/propulsion system, which is a requirement, but merely an auxiliary thrust system independent of the helicopter's operation itself. Otherwise you could just hang a big enough jet on anything and just force your way through the air, with no advance in helicopter technology. The X2 TD does not use any auxiliary means of propulsion, the pusher is powered by the vehicle's normal engine/transmission and so would qualify as a helicopter for record purposes.