Firstly,
I'd like to congratulate Mr Vuichard on the making of a very professional film about crop sprayers.
The colours, backdrop, photoshop and music (especially) make for a very convincing story line................
until you realise this is one seriously FUC*ED UP commercial.
Either there is some meaning lost in translation between Mr Vuichard's interpretations and technical languaage or Mr Vuichard is one helluva'n ignorant pilot.
Nothing wrong in being an ignorant pilot - (one just posted on the 10th)....but it's best if they fly quietly out of harm's way somewhere in the boon docks chasing wart hogs.
We have been round the buoy with this particular Mr Vuichard before and as long as he continues to promote a very very dangerous message to those in the helicopter community that this is the gospel when it comes to VRS - I will continue to correct him.
Let me list facts and plead with the 'converted' that this message is WRONG, so very WRONG.
1. VRS is a fully developed aerodynamic state where the controls of a helicopter do not respond normally. Therefore adjustments/ corrections to these controls are sporadic.
2. VRS by definition includes a RoD in excess of 75% OF THE DOWNWASH SPEED OF THE MAIN ROTORS. this means RoD's in excess of 300,400,500 feet per minute - to start with and can reach thousands of feet per minute.
3. VRS is exacerbated by PULLING POWER. It accelerates stall.
4. Incipient VRS [IVRS], is not VRS.
5. Alternatively, flying controls react normally during IVRS.
6. Departure from the airstream beneath the tip path plane will diminish IVRS. This is normally achieved using the cyclic in either a sideways or forward direction. Departure to the side, rear or front of the vortices removes the cause.
7. IVRS rarely if ever exceeds 300 fpm.
Inaccuracies in the video:
(a) There is an "N" in Robinson.
(b) The subject matter he refers to has an "I" missing from the mnemonic: "VRS". The video would then make sense.
(c) A minimum height loss of "20-50 feet" cannot be achieved during VRS as the a/c is descending hundreds if not thousands of fpm.
(d) the audio suggests pulling power initially. This will of course accelerate loss of lift developing at the root, further aggravating the RoD.
(e) None of the controls would respond to the pilot's inputs if the demo actually showed VRS.
For those out there who wish to accept this video in its entirety - as gospel. You are living on borrowed time. It is essential you grasp the fundamentals of IVRS and then VRS before you even think about attempting to emmulate these manouevres for yourself.
Vertical Freedom lives and breathes the perfect environment for VRS in that rarefied atmosphere up there in the mountains - his comments require serious thought and consideration - because he is of course: correct.
As for Crab and myself who taught this for a living...................