Or, to put it another way, what is the strongest helicopter in the world? Obviously, double rotor heli’s are stronger than single… Is there such a thing as a triple (or quadruple, etc.) rotor helicopter? If not, why not?
The Mi-26 HALO?
I believe it is the MI-26 Halo that can carry 20 tons.
According to most sources, the mokst powerful helicopter in the world is the Russian-made Mil Mi-26:
It features an 8-blade single rotor, which makes it unique among heavy lift helis. Its nearest competitor to date is the Sikorsky CH-53, which can lift 16 tons, with a 7-bladed single rotor.
I still say it is the Halo.
No, it’s the HALO.
We have a late entry, the Mi-12 “HOMER”:
Yup, that must be a winner.
And its possibly the most unlikely thing to take flight, see here what I mean…
http://www.airliners.net/search/photo.search?aircraft_genericsearch=Mil%20Mi-12&distinct_entry=true
Jebus! That thing is huge; it looks like a jumbo jet with a couple Bell Jet-Rangers bolted to the wingtips. Is that a MiG 29 parked next to it?
…and some film of it flying, [Dougl Adams]a bit like a Vogon battlecruiser hangs in the air just like bricks don’t[/Douglas Adams]
As can be seen by the other posts, this isn’t necessarily true. One thing a double-rotor helicopter does have over a single-rotor helicopter is that it tends to have a greater CG envelope.
Why no multi-rotor systems? Aircraft are compromises. A Piper J-3 Cub is a good aircraft for flying low and slow and landing in pastures. But you wouldn’t want to get in a dogfight in one. You’d want an F-14 for that; only you wouldn’t want the F-14 if you were going to land on a riverbank to do some fishing. A 60-year-old J-3 is still fairly reasonable pricewise, but it’s not a great cross-country machine because of its slow speed. A Beechcraft Bonanza is a nice way to cover a long distance in a reasonable amount of time. Only last time I looked (about ten years ago) they were comfortably over half-a-million simoleons new. The Bonanza is a much more complex machine than a Cub, and has much higher performance.
What makes an aircraft fly? Money. The higher the performance, the more money it takes. So designers and aircraft builders try to get the most performance with the least amount of expensive complexity. Helicopters are particularly complex. On a fixed-wing aircraft the wings are bolted to the airframe and they’re expected to stay there. Rotor blades flap up and down, twist longitudinally, ‘lead and lag’ (i.e., on a multi-blade system the angles between the blades vary), and go round and round. They’re subjected to a lot of stress, and mus be replaced periodically. For example, the rotor blades on a Robinson R-22 must be thrown away and replaced every 2,000 flying hours. 4,000 for a Schweizer, but there are three of them.
So adding rotors increases the initial cost and complexity, and increases maintenance costs, and increases the number of things that can go wrong. And you’ll need more and/or more powerful engines to turn them. What do they buy you? Greater latitude in loading. It’s a better compromise to have one or two main rotors.
I’ve seen a model helicopter with 4 rotors, but never a full-scale one - probably too complex and expensive.
Your Mom?
and of course the smile isnt working for some reason…sorry it was the first thing that popped into my head.
All right! Now, what if you put it on a treadmill?
If you’ll accept hybrid technologies there is the Piasecki Heli-Stat, composed of four helicopters mated to a blimp. The US Forest Service looked into them in the 1980s for moving timber (I remember there was one on the cover of an old Popular Science back in the 80s). Projected lift capacities were pretty huge, the link below mentions 60-200 tons.
SNAKES ON A PLANE ON A TREADMILL!
Er… nevermind.
This thread made me think of the CH-54/S-64, which looks pretty weird, but I guess it doesn’t carry quite as much at the others.
It may not be the record holder, but [email=http://www.boeing.com/history/mdc/graphics/hist192b.htm]The Hughes XH-17 has to be up there in the strangeness category.
As an aside, in the Mi-12 both rotors were powered by all four engines - that way they maintained some power even in the case of catistrophic loss of both engines on one side.
Arrgh! - newby error. I meant to include a link Hughes XH-17
The Halo lifted a Rio in 1960 once for 20 minutes!