In answer to the first post.. I say learn the constant angle approach well.. the rest will come later.. The "airfield approach" won't work so well in a field with that hidden cable running across it.
Quote:
I'm sure someone will correct me if I'm wrong, But I do not believe the H/V curve only applies at take off.
It would also apply for example, when ever the aircraft is within the shaded areas, right? which can include low flying (for example hovering at 150 feet). You would not, for example approach vertically from 500 feet with zero airspeed, because if you did, you would be within the shaded areas. Therefore the shaded areas of the H/V curve are to be avoided, including whilst landing.
A H/V curve would be different for different collective settings... I imagine the published h/v curves must apply to a collective setting used at t/o and so would be inherently safe through all flight envelopes including landings (obstacles aside!). But the landing envelope would have a much "free-er" h/v curve if a collective position could be defined... it can't though for obvious reasons...
To take extremes...
Vertical autorotation?
40knots constant angle auto?
Perhaps someone more knowledgable could confirm: Constant angle approaches through the H/V shaded areas would surely allow you to drop into autorotation safely at any point?
The point someone made about not making your helipad from a Constant Angle Approach in the event you need to auto... I believe could also apply to
the low /high speed approach.. imagine the extreme that you are 1 mile out on approach low and fast... your k.e wont save you.
yet I can imagine being able to make the spot from a bit high and slow by dropping into a steep auto.. imagine being way to high... you could hypothetically auto into your pad.... e.g from 2000ft above your oil platform...? Certainly not from the shaded area in the H/v curve with high collective....but with a low collective..?
Someone suggested the safest approach is a perfect auto... a little tounge in cheek I assume... so I will go one further..
the safest way of guaranteeing you will make your pad is to be above it.... by vertical auto?
(touch paper lit... standing back
)
(just pre-empting the Vortex Ring comebacks... Of course this is not a practical suggestion....!!!) And by the way... I do wonder about the previous suggestions that you "not worry about VRS if you are 'approaching into wind'".. you never know.. e.g the high ground you thought was flat ahead of the Lz blocks the oncoming and wraps the wind in broadside.. or even behind you..... very common... your fast and low approach might catch you out then too......
