Whop Whop Whop!

[Cole]

Thanks BM, will do

[transquebecniece]

Somehow every thread I start goes waaaaayyy off course.

 

So what is the posibility of a person say me to get into a heli for free? :up:

So, Coleman. How do you go from "what creates the whop, whop, whop sound" to bummin' a heli ride without strayin' "off course?" Here's your perfect segue: You NEED to hear it firsthand, from INSIDE the heli, to complete your research project. :prop: Just a thought.

[Cole]

Hey, if were going to be off course in my thread, I should at least get something out of it... btw, just saw the newfie thing for da first time bye! haha.

[Elvis]

So, Coleman. How do you go from "what creates the whop, whop, whop sound" to bummin' a heli ride without strayin' "off course?" Here's your perfect segue: You NEED to hear it firsthand, from INSIDE the heli, to complete your research project. :prop: Just a thought.

 

But you don't hear it inside the sound is projected away (fwd due to the doppler effect) from the helicopter

[transquebecniece]

Yahbut, I could get away with that excuse. Cole, need I point out that YOU are the one who got your thread off track? :boff:

[Skids Up]

But you don't hear it inside the sound is projected away...

 

Not true! If you set it up right, (not that I would ever do it :shock: ) you can hear it. Best sound in the world...

 

...unless you're hiding in a rice paddy, I would think!

[407 Driver]

..reminds you of your time back in 'Nam, Skids?

[Skids Up]

Now you've done it....

[transquebecniece]

Incoming! Whop, whop, whop!

[marc]

Hi guys, new to the forum. Thought I'd chime in on the whole whop whop whop stuff. This whole theory is based on what I learned in maint. school ( 6 weeks to go :up: ) and persional ideas.

 

It will be much more pronounced on two-blade under-slung set ups (204-5-6) due to the restricted amount of travel or the blades fore and aft within the disc. Also, I think the more blades the smoother the rotor disk(less chance for the air to swirl out of the disc).

 

You ever hold a rope above your head or beside you and swung it around. It makes a similar sound, but notice how the focus of the sound is from the spot where you start the "flick" of the spin again.

 

I think the whop whop is the cumulation of the shock wave building along the blade and then firing the sound toward you at the point where the relitive velocity of air is the greatest.

 

In forward flight you would have the switch of velocity from advacing to retreating when the blade is fore aft, so when the helicoters pointing at you you hear it (doppler effect helping too).

 

Just a theory, any thoughts?