"No, I don't thank you for the fish at all" (notindetroit)
09/26/2015 at 10:16 • Filed to: planelopnik, helicopters, nazis, twin rotor, sikorsky, flight
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"No, I don't thank you for the fish at all" (notindetroit)
09/26/2015 at 10:16 • Filed to: planelopnik, helicopters, nazis, twin rotor, sikorsky, flight | 3
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If you like to browse Oppo all day (and I know you do, c’mon, we all know work productivity is just a figment of Pointy-Hair Guy’s imagination) then you’ve probably read the “This Day in Aviation History Speedround” posts by ttyymmnn. The !!!error: Indecipherable SUB-paragraph formatting!!! included the Sikorsky VS-300, an important helicopter. But why is it important? Is it the first helicopter? The first practical helicopter? The prototype for the first mass-produced helicopter? This is something I ended up !!!error: Indecipherable SUB-paragraph formatting!!! with ttyymmnn in the comments section and it bears a little more investigation.
Now, helicopters go back quite a bit and are actually among the first man-made objects to take flight along with kites. The Sept 12-15 edition of the Aviation History Speed Round mentions Chinese playing with helicopter-like toys; it’s been said the Wright Brothers were inspired by a similar toy to produce their own efforts for a flying machine (eventually going a very different route). One of da Vinci’s most famous paper inventions is his screw-type helicopter and during the last days of the American Civil War a self-proclaimed inventor promised a desperate Confederacy that his flying machine would pulverize the North into submission, conceptualized as a framed contraption that looks like a cross between something out of a Jules Verne novel and a room-sized mechanical computer of the era. Needless to say nothing came of it as there isn’t any “Abraham Lincoln: Helicopter Shooter-Downer” movie made.
Yes all you get is this teensy-tiny image. Mobile users might as well forget it. Image public domain via Wikipedia
But helicopters weren’t all that far behind fixed-wing aircraft as something we’d say is close enough to a helicopter took flight in 1907. This makes helicopters roughly as old as the Model T. The inventor was a Frenchman named !!!error: Indecipherable SUB-paragraph formatting!!! and his invention, pictured above, looked more like an extended bedframe ready to play ping pong than a revolutionary flying machine. It was powered by an Antoinette which put out approximately 24 horsepower. What’s an Antoinette you ask? Why, it’s the world’s first serial-production V8 engine of any kind, originally produced for the French aeronautical industry and principally for the aircraft of the same name. Yes your Challenger Hellcat has the French to thank for its existence. Cornu’s craft could go up into the air for a little bit for a short height, and then go back down, and that was absolutely it. If only it had a Hemi....
BAM! V8 right there! Public domain via Wikipedia
This was pretty much the state of vertical flight for decades to come - people were still trying to figure out how to build a helicopter light enough to fly aloft with whatever power outputs they had. And it wasn’t like they had little to work with - the average aero-engine of the 20s spit out 500+ HP easily, even if it weighed as much as a brickhouse (and in typical fashion of old-time engineering, was built like one). The main problem seemed to be at first trying to figure out the airfoil shape (even into the early 1910s trying to nail the Wright Bros.’s secret was a bit of a mystery to some people, particularly the eccentric type of person wanting to “improve on the new theory of flight” even though by this time aircraft were starting to roll out of factories like cars) and then figuring out how to keep those airfoils productive. Unlike a fixed-wing aircraft, where the wing has little to do but sit there while it does the heavy-lifting, the dynamic forces of a rotor (itself spinning, plus moving through the air in a horizontal direction, plus potentially moving through the air in a vertical direction at the same time, all at variable speeds) means that it’s much more complex than just sticking a rotor to an engine shaft and get the whole thing crankin’. In fact it’s much closer to a delicate ballet act in terms of keeping parts well-choreographed so that, much like novice ballet dancers, they don’t start whacking into each other and really ruin your day - or barring that, able to produce lift dynamically and efficiently, making the difference between flying to the top of Mount Everest and maybe making for an interesting commute to your mailbox.
That’s where the true genius of Sikorsky’s helicopter lay - he figured out a complex control system that allows the rotor blades to be dynamically adjusted to create lift and horizontal motion at the same time - and vary the speed or pitch of those rotor blades to go faster or slower (or backwards or sideways) or rise or descend at whatever speed the operator needs. His anti-torque rotor stabilized single-main rotor design became the pattern for the vast majority of helicopters to come.
There’s only two problems with Sikorsky laying claim to that distinction - and both of them come from those wacky villains of history, the Nazis.
Yes yet another tiny picture to haunt mobile users. Image credit “Born2Flie” via Wikipedia.
The first problem simply concerns whether or not Sikorsky really was first. That thing at left is a Focke-Wulf Fw 61, the first practical helicopter...except Sikorsky’s VS-300 is the first practical helicopter, right? The Fw-61 probably came later, even if only a little bit, right? Nope, the Fw-61 first flew in 1936 - about three years two months before Sikorsky’s first flight. Almost two years prior to Sikorsky’s first flight famed Nazi test pilot Hanna Reitsch flew an Fw-61 inside a sports arena in Berlin, becoming the first female helicopter pilot ever (in fact one of the first pilots of a practical vertical lift machine period). Like the VS-300, the Fw-61 was actually cobbled together from other aircraft - whereas the VS-300 is essentially a hacked-up Army training glider, the Fw-61 started as a Fw-44 biplane (the German version of the American Stearman) with the wings ripped off and rotors stuck on instead. Oh, and don’t let the little propeller in front fool you, this is not an autogyro, that thing’s stuck on there strictly to cool the engine and was intentionally sized too small to provide forward movement.
An ex-Luftwaffe Fa-223 twin-rotor helicopter, public domain via Wikipedia
The other bone to pick with Sikorsky concerns all the claims made about the single-main rotor single-anti-torque rotor configuration somehow being superior (as with the video above - sorry, Mo). Sure, compared to the two, three or even four-rotor or more monstrosities that proceeded and barely got off the ground, the VS-300 was sleek, compact and lithe. The overwhelming majority of past, present and future helicopter designs continue with this now classic setup, from the tiny little !!!error: Indecipherable SUB-paragraph formatting!!! that you can train on to the biggest and baddest one of them all, the !!!error: Indecipherable SUB-paragraph formatting!!! .
Yet there’s a certain illogic to this setup. That anti-torque rotor represents a pretty bad compromise - other than changing the direction the helicopter’s pointed at and preventing it from spinning out of control it doesn’t do anything. It’s dead weight and aerodynamics. Two main lift-rotors accomplish the same things - and contribute to thrust and lift at the same time. It’s why arguably the most badass helicopter of all time, the !!!error: Indecipherable SUB-paragraph formatting!!! uses a twin coaxial rotor setup. One of the most successful helicopters of all time, the CH-47 Chinook, uses this twin-rotor setup as well. You know the Chinook, the one that shows up in the media all the time precariously perched over a cliff as special forces soldiers rush in or out? The one that helped kill Osama Bin Laden? Again, the Germans were ahead of the game before Sikorsky or anyone else. Notice that the Fw-61 has twin rotors to counteract each others’ torque? That same design grew into the !!!error: Indecipherable SUB-paragraph formatting!!! (Dragon, or...Kite? Ok, whatever Wikipedia), the proto-Nazi Chinook of WWII. Like the Chinook, it became a real workhorse, being used for everything from standard cargo transport duty to special forces raids - which would be the first special forces raids by helicopter in history, by the way. Or it would’ve been had the helicopter not broken down. It was also the first to do a vertical recovery of a broken-down aircraft - or it would’ve been had it not broken down itself. Yeah there were a few bugs to fix. It did become the first helicopter to cross the Channel, successfully, without breaking down, by RAF pilots after the war. Maybe some forms of technology are just allergic to Nazis?
So here’s my question to you - do we remember history a little incorrectly? Is it right or wrong to award Sikorsky the honor of the “first” helicopter, or would we rather shy away from any Nazi associations? Why do most modern helicopters have just a single main rotor when there are real advantages to a tandem rotor helicopter?
Please stay up all night thinking about this and return to me with an answer in the morning.
RamblinRover Luxury-Yacht
> No, I don't thank you for the fish at all
09/26/2015 at 10:36 |
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I’d argue that ease of service and some attractiveness for a very small platform are worth considering for the simple single-with-antitorque setup. Sure, twins are nice for big platform stability - I’d argue that for a lot of things the Kaman Huskie’s mesh setup is better than Kamov’s coax - but for most small helicopters, building a coax setup would be utterly pointless. Coax rotors small enough to make use of the available power of a small engine pushing *two* aren’t obviously better than just having one big one. Having a bigger area of thrust is not a bad thing. Nor is the tail rotor a total waste - there are inefficiencies, but the anti-torque thrust directly translates into thrust the main rotor puts down. Not as well as a twin, but it’s useful. A tail rotor adds weight, but any mechanism to get two rotors out of conflict also adds weight - six of one, half dozen of the other. The tradeoff for the increased stability and moderately increased efficiency is mostly weight, serviceability, and lack of immediate pivot capability. Eh.
TheRealBicycleBuck
> No, I don't thank you for the fish at all
09/26/2015 at 10:48 |
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There are several problems with dual rotor designs. With more than one rotor, whether in tandem or side-by-side, the rotors must either be spaced far apart, designed to rotate in different planes, or be mechanically linked in order to mesh without hitting each other. In all three designs, there are additional costs due to duplicated control mechanisms, additional power shafts, and in some cases, multiple engines. Other complications arise with the layout of the rotors themselves. When spaced far apart, the machine requires much more operating space. When stacked, one rotor operates in the wind shadow of the other, complicating aerodynamics. Intermeshed rotors are the most complicated mechanically and have handling issues because they are so stable.
So, a single rotor design is less complicated, more compact, less expensive to design and build, and has more than adequate performance, making it the dominant design.
ly2v8-Brian
> No, I don't thank you for the fish at all
09/26/2015 at 12:12 |
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It is right, because his design is the most successful.
JawzX2, Boost Addict. 1.6t, 2.7tt, 4.2t
> No, I don't thank you for the fish at all
09/26/2015 at 18:32 |
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single rotor plus anti-torque makes for a much more compact machine with less mechanical complexity and weight. I think that those advantages, in the real world of human-operated and-carrying craft far outweigh the increased efficiencies of a multi-rotor system.