Upward visibility?

[alwynhartman]

Why is visibility above the helicopter from the pilot seat important? Ive heard that one of the drawbacks that tandem helicopters like the HUP and particularly the JOV-3 and MC-4 had was that the forward rotor mechanism blocked the possibility of a view.
Why is this an issue?

[hillberg]

Try a good tight NOE turn without it.:ugh: The more glass the better.:ok:pitch & roll in turns WoW!:}

[Gomer Pylot]

It isn't, in most cases. In the BH412, the greenhouse window above the pilot must be covered in order to fly IFR. I've had vertigo from the flickering shadow of the rotorblades on the instrument panel in a Bell 47 (TH-13), and having a window directly above the pilot can be a real problem. I almost never look through the greenhouse above me, and wouldn't mind at all if it weren't there, but it's traditional, so manufacturers keep providing it.

[Arm out the window]

I want overhead windows there for view into the turn, particularly towards the seat you're not in, when doing a steepish turn.

When they're covered or not present, I feel I have to really crane forward in the straps to get an adequate view in a tight turn, and even then it's not good enough.

[alwynhartman]

So the consensus seems to be that they are only really useful when the turn is steep and tight but during level flight they can, in certain cases, prove to be a source of irritation.

Thanks! I think I have my answer!

[Savoia]

During my time in Papua New Guinea, and like many who have flown in that testing-ground of rotary skills, I flew numerous tasks for several mining companies exploring for gold.

The normal routine would be to insert a team of geologists from the base camp (usually something in the order of 4-5 geos) each with one or two assistants meaning that each geo and his crew was a separate sotie. Once inserted you would then return some hours later to extract them and re-insert them elsewhere (all without GPS over a sea of green foliage, you know, proper bush flying!).

Insertions were along creek beds and almost every disembarkation was made with the craft in the hover. It was in this role of supporting stream-bed sedimentaiton sampling that I grew to admire the Hughes 500; in fact I simply couldn't imagine successfully carrying-out this work in anything but the 500! The compactness and responsiveness of the 500's rotor disk delivered precision manoeuverability combined with a stability which to be experienced to be believed.

I was reading, with some amusement, TopEndTorque's self-depreciating comments on the Snoopy (http://www.pprune.org/rotorheads/450024-snoopy-flying-inside-stadium-2.html) thread relating to how flying training used to be performed and can confidently say that the instructors antics he refers to were all experiences one encountered during mineral exploration flying in PNG.

Aside from the hovering disembarkations, often with one skid up against a sufficiently large boulder, was the matter of accessing the stream-bed itself. Generally speaking, across PNG, the jungle canopy is dense and finding access to the parts of the river the geo wanted to go to could be a challenge. When eventually an 'opening' was found it regularly required the patient process of 'weaving' beneath several layers of large sprawling and overhanging branches. The branches were huge by the way so we are not talking about manoeuvering within handfuls of feet but a good few metres instead! :E Anyway, it could take a few minutes to lower the angry bumble-bee down to the stream through the thicket.

Once there, and on more than one occassion did the young Savoia exclaim "Santa Madonna!" as he peered upwards through the skylight to observe what what seemed to be a solid ceiling of jungle canopy!

Perhaps needless to say, weaving back up through the layers of overlapping branches was a more exacting excercise and was not helped by the fact that the branches were now being 'sucked' down towards you (instead of being blown away during the descent).

Long story short .. ascending out of the stream beds would have been impossible without the skylight. In fact the ascent was made with almost constant use of the skylight!

The other application of couse, as discussed above, (and this is more crucial in some aircraft than others) is visibility during high-rate turns when the skylight serves as in important access to visual reference in the lateral plane.

Ah, the memories of youth!

.

[ShyTorque]

I was taught to fly "see and be seen". Irrespective of the phase of flight, be it turning, S & L flight (or climbing/descending), the bigger the window, the more you can see.