Great discussion!
To review:
(1)VRS can be eliminated as a concern for average landing situations into the wind and the 300fpm rule is incorrect.
(2)What a lot of pilots think is VRS is actually settling with "insufficient" power.
With that established, what is the ideal approach for a normal airport landing?
Obviously, My instructor should be teaching the proper approach,but I am not sure he is.
I hate to second guess what he says but it is pretty clear that even instructors do not always have the proper information.
This is what he drew on the chalk board for a normal approach:
A 12 degree glide slope with 50kts at 50 feet then level the fuselage and be at 20 feet with 20kts and 10feet and 10kts.Easy to remember! He said "just keep a bug on the windshield fixed to maintain the same glide angle all the way to touchdown and bringing in the power will stop the forward travel without any need for backward cyclic."
I showed the instructor a drawing I had prepared of a 12 degree glide slope on the next lesson. A 12 degree slope is 4.75 to 1.
So at 50 feet agl we would have 237 horizontal feet (50 x 4.75 = 237) to bring the ship to a stop and I thought that would require more of a quick stop maneuver.
He then agreed that, as a student, I could start the slowing process at tree top level, about 100ft instead.(looking at the trees along the runway as we fly down the runway aiming for the windsock area about mid field)
As Devel 49 suggested above I would much prefer to come in slower, perhaps 30kt.That's what helicopters are all about, right! My assumption is,the instructor is trying to teach a method of approach that improves the chances of a successful landing in the event of power loss by coming in faster than I would prefer.
Since VRS can be eliminated as a concern, only the HV curve need be factored into the approach method, I think.
Looking at the HV curve and my glide slope drawing, 12 degrees is into the danger zone (25kts at 25 feet).
At 6 degree glide slope the danger zone is avoided.
If you look at the HV chart and try to draw a glide slope on the chart itself,that doesn't work,the units do not match with an actual glide slope.The data from the HV chart has to be transfered to a different glide slope chart layed out in feet on both the side and bottom of the chart.
So I think maybe the instructor got the 50kt-50feet 20kt-20feet rule from the HV chart.
I understand sometimes flight in the HV danger zone is necessary and look forward to practicing steep and vertical approaches. But still, I need to define a normal approach.