Developer Comment by Adam Rivera on May 14, 2012 at 1:29pm

Love this. Thanks for sharing your find, Chris.

Developer Comment by R_Lefebvre on May 14, 2012 at 1:55pm

Yes, helicopter physics is pretty amazingly complex.  Way more than most people realize.  There are so many asymmetrical force interactions going on.  Most people don't realize that it's actually normal for a helicopter to hover, tilted slightly to one side.  They never hover perfectly flat.  (this is why in-flight levelling was so important for me!).

Developer Comment by R_Lefebvre on May 14, 2012 at 2:16pm

I'd like to see an exec from Discovery or TLC explain to me why this guy doesn't have a show, and instead we get... well, all the crap they play normally.

Comment by Ellison Chan on May 14, 2012 at 4:56pm

So, what's the physics behind why the Chinook is faster than an attack heli, like the Apache, I wonder.  Is it just because it has two engines and two rotors?

Comment by William Morse on May 14, 2012 at 6:05pm

the Chinook has counter rotating blades so the gyroscopic procession of the blade stall effect on a single rotor heli is negated because the Chinook is supported symmetrically by opposite sides of the two rotors. 

Developer Comment by R_Lefebvre on May 14, 2012 at 6:21pm

@William, while technically correct, I'm not really sure that's the real, or only, reason.  I say that because the Chinook is far from the fastest helicopter ever made.  Many single rotors are faster.  It could be more about horsepower, aerodynamics, loading, etc.

Comment by Ryan Alexander Bahr on May 15, 2012 at 12:02am

Though I am sure there are other factors, I believe the reason he was stating that we should know that chinhook was fastest was due to the fact that the top limiting speed of the blade due to the speed of sound and pitch on the retreating blade.

Interesting fact, the Chinook has a wiki Max speed of 197 while a Westland Lynx (regular heli) has 201, though the Lynx has the fastest recorded topspeed for a helicopter of 247. The rated max speeds are not that different though. I'm curious if blade speed is really the limiting factor, as the chinook's blades are much larger and therefor would have less RPM though still providing huge amounts of lift. I really believe there are so many trade offs that its possible that at those speeds aerodynamics are key, the chinook having marginally more drag that it would overall reduce its topspeed at those airspeeds. Here is the Drag force equation, with the variables representing air density, velocity (notice that the force increased by velocity square, high speeds need much more power to overcome drag), coeffecient of drag (aerodynamic-ness), and then area. But who knows.

Moderator Comment by Gary Mortimer on May 15, 2012 at 12:17am

BERP

Developer Comment by R_Lefebvre on May 15, 2012 at 1:35pm

Huh, I didn't realize the Chinook's rated top speed was so close to the Lynx's.  Very interesting.  I should have done more research.

The Gazelle, another "fast" helicopter is rated at 193mph.  Cobra 172mph.  Apache 158mph.  EC135 178mph.  

There are a number of single rotor choppers that have speeds near the Chinook, but only the Lynx is faster?  Considering how old the design of the Chinook is, that's really something.  

Comment by Ellison Chan on May 15, 2012 at 9:48pm

But, nothing was as fast as theAirwolf.  It was supersonic! ;-)

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