Edson AB crash, VRS?

[RVDT]

The info is there for some "fag packet forensics".

Assumptions:
1 crew
End of the mission and heading home with "min" reserves.
Mass ~ 1500 kg

For reference use passing over the vertical pole in the perimeter fence in the video as where it all started.

Using the length of the aircraft fuselage to eyeball the height above the ground = 35 ft x ~ 3 = ~ 105 ft.
Time stamps from the video passing over the pole to impact point = ~ 5-6 seconds so ROD ~ 1000 - 1300 fpm give or take. As the 350 normally only has a standard VSI it would not indicate this rate due to lag in the timeframe involved.

Again "fag packet" calcs would point to the induced downwash velocity around ~ 1600 - 1800 fpm. Crabs estimate of ROD requiring 50-75% of your downwash is in the ballpark for VRS .
Keep in mind the lighter you are the easier it is to get into VRS due to lower disk loading and resultant lower downwash velocity.

Go and talk to a Lama pilot (not so many left) and wonder why Mr Vuichards videos always have a Lama in them?

Use the smoke after the impact to estimate the wind speed and direction versus the groundspeed after passing the perimeter vertical pole. I would guess IAS was near zero just after passing the pole at about 90 ft.
There is a pitch attitude and ROD change as it passes behind the horizontal perimeter fence pole where I am guessing it has just dawned that "something ain't right" and someone reverted to being a passenger.

As the camera tracks the aircraft pretty well watch the video with your hand covering the lower part so you remove any indication of movement and you can only see the aircraft. Would you fly this profile with zero airspeed?

As to "overpitching" which is just poor handling of power margins versus inertia - meh! If the wind was blowing the other way we wouldn't be having this convo here? All helicopters hover and climb as bad as each other at MTOM due to commercial and design specification minimums.

As many of my old crusty peers over the years have said - "If you are flying a helicopter and do not know constantly what your local wind speed and direction is - it was suggested that you just land, get out and seek employment in another field.

It is actually quite difficult to get into VRS and requires some effort to demonstrate but one day you will get lucky if you keep the effort up.

As an aside B3 blades are B3 blades and cannot be fitted to other models with the exception of maybe a 355N or NP. Yes they may look similar with grey paint but...............internally they are different. A B3 is not just a B2 with a "phat" engine. I know people who have tried unsuccessfully to put B2 blades on a B3 and had to throw away a lot of parts on discovery of their error!