Airplane on a Conveyer Belt returns in...

[rogwar]

I absolutely love the sound of a huey in flight   

Particularly when it's coming and not going!

 

[Wingnutt]

I never liked riding in helicopters because there's a fair probability that the bottom part will get going around as fast as the top part.

[Denholm]

Only if the tail rotor fails. But if it's any comfort. The G's encountered if the tail rotor fails and the helicopter actually begins spinning will cause loss of consciousness before impact.

[ebfd11]

  Dropkick…    Ch-47D Chinooks travel 196 mphand the UH-60 Blackhawk can travel at 221 MPH They are the two fastest in the American Inventory.

[HPriller]

a CH-47 chinook has rotor diameter of 60ft so its circumfrence is 188.4ft. if at 1000rpm, the blades' tips are turning at 188,400ft/min=11,304,000ft/hr
11,304,000/5280=2140mph. as you can see, its clearly above the speed of sound.

Whoa, just a second here.  1000 RPM? A helicopter that size won't have a rotor head speed anywhere near that, more like 160rpm.

[ebfd11]

Ok gents here is the specs for the CH 47 right from the Boeing web site:

http://www.boeing.com/rotorcraft/military/ch47d/ch47dspec.htm

Hopefully this answers any quetions

[HPriller]

Doing the math for Ch47 rotors given the rotor speed of 225 rpm from the previously posted website, you get a tip speed of ~482mph.  Even with 200mph forward speed added, the advancing blades will still be traveling below the speed of sound at the tip.

[Denholm]

Which goes back to me mentioning complications once the blades break the sound barrier. From what I've heard, uncontrollable vibrations are encountered when helicopter blades constantly break and re-enter the sound barrier. These vibrations eventually crack and break the blades.