Originally Posted by
admikar
Maybe hover wasn't the right word. Vertical landing and subsequent take off. And I am not talking airport-to-airport flying. Yes, it is less than 5-10% of flight time, but what's the point sending it to some unprepared landing site during combat if it can't land or take off afterwards. And that will be the case sooner or later. Yes, I have seen all those videos.
Now, all this being said, what I said previously is from what I have known before CTR and Sultan gave me some new information. Thx for that.
Another thing I would like to know is downwash? We know V-22 has abysmal downwash. I guess with larger discs Valor less so. But how does it compare to other helicopters (not just Blackhawk)?
CTR and Jack Carson provided good data already, let me try to add a bit more.
I can't figure out what you mean by, "...but what's the point sending it to some unprepared landing site during combat if it can't land or take off afterwards". Why would you think a production V280 wouldn't be able to operate from unprepared fields? Kinda goes with the territory, and you'd think the Army might have said something if they didn't believe it could. Unless you're referring to the phony Sikorsky-pushed issue about vehicle size? Remember, the Army specified the minimum number of craft that could operate from a defined landing field with a required distance between spinning rotor tips and from surrounding terrain/vegetation, and the V280 meets the acquirement
Regarding downwash, V-22 has a lot, what it has is not solely a function of being a Tilt-Rotor. There are two big factors in its development that contributed to this. The first was the desire to be able to operate from the two spots abeam the island on the smaller amphibs of the time. This meant that the proprotors had to be constrained to a diameter less than optimum for its size and weight. Naturally, this raised the disk loading.
The second was the engine. During the design phase the Gov't told Bell/Boeing to plan on a Gov't supplied engine of a certain size, weight and fuel burn. Then during design the Gov't chose to supply an engine that weighed more and burned more fuel. This upped the weight on the craft and requiter a heavier structure in places to support this . The result was that those constrained proprotors had to lift even more weight, hence more disk loading hence more downwah.
Neither of those conditions apply to the V280.