# Sikorsky "Ion Airfoil"--why no development? **URL:** \ **Category:** Great Debates\ **Created:** [September 7, 2003, 4:55pm UTC](https://boards.straightdope.com/t/sikorsky-ion-airfoil-why-no-development/200111 "2003-09-07T16:55:11Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Scott\_Dickerson](https://avatars.discourse-cdn.com/v4/letter/s/f04885/32.png) [@Scott\_Dickerson](https://boards.straightdope.com/u/Scott_Dickerson)\ **Post date:** [September 7, 2003, 4:55pm UTC](https://boards.straightdope.com/t/sikorsky-ion-airfoil-why-no-development/200111/1 "2003-09-07T16:55:11Z")
Back in the mid-60s that prestigious journal POPULAR MECHANICS ran an article on a new propulsion system being developed by the Sikorsky aircraft people. This was a lifting-body system with no moving parts: lift is provided by ionizing air, which is then forced downward. A working model had been created, and was photographed in flight. (Note that this is an in-atmosphere propulsion system, not the “ion drive” of spacecraft.) “Neato-jet!” I exclaimed, and waited for the first full-scale craft to take, er, wing. I’m still waiting. Obviously the basic idea “works.” Anyone know wha hopp? ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [September 7, 2003, 5:24pm UTC](https://boards.straightdope.com/t/sikorsky-ion-airfoil-why-no-development/200111/2 "2003-09-07T17:24:53Z")
Check out [this search on “ion lifters”](http://www.google.com/search?sourceid=navclient&q=ion+lifters) for all the latest details. The upshot is that it works on small models, but scaling it upward to large vehicles is unfeasible and would required huge amounts of electricity to make it work. It has been discussed here on the SDMB several times, just search for “lifters”. ---
**Author:** ![Doc\_Nickel](https://avatars.discourse-cdn.com/v4/letter/d/5fc32e/32.png) [@Doc\_Nickel](https://boards.straightdope.com/u/Doc_Nickel)\ **Post date:** [September 7, 2003, 5:34pm UTC](https://boards.straightdope.com/t/sikorsky-ion-airfoil-why-no-development/200111/3 "2003-09-07T17:34:32Z")
I couldn’t say with any real answer concerning that particular engine/drive, but there’s plenty of reasons that something like that would never make it past the experimental stage. Things like fuel efficiency- if it takes more energy to achieve the same lift as a conventional engine, where’s the benefit?- and max thrust- if the engine can only, due to physical constraints, put out just so much power, then it will be limited in application. There’s also construction costs, especially when combined with either of the above- why pile cash into ceramics and carbon fiber to have an engine that puts out less power while consuming more fuel?- or material lifespans; an “ion” engine uses a plasma jet, as I recall, which means exotic materials are needed to resist the temps involved. Even some ceramics eventually erode at 5,000 and 6,000 degrees. I’m not sure how the Sikorsky system worked, but I can’t imagine “ionized” air providing a great deal of lift. I would imagine if a small scale model had an umbilical to an off-board power supply, it could indeed fly, but that system doesn’t necessarily scale up adequately to full size craft. What is it, double the weight of the plane and you have to _quadruple_ the area of the wing? ---
**Author:** ![ElvisL1ves](https://avatars.discourse-cdn.com/v4/letter/e/5daacb/32.png) [@ElvisL1ves](https://boards.straightdope.com/u/ElvisL1ves)\ **Post date:** [September 8, 2003, 3:51pm UTC](https://boards.straightdope.com/t/sikorsky-ion-airfoil-why-no-development/200111/4 "2003-09-08T15:51:27Z")
> [@](#): > > \*Originally posted by Doc Nickel \* > What is it, double the weight of the plane and you have to _quadruple_ the area of the wing? \*\* Right. Wing area scales only by the square of the linear dimension, but mass scales by its cube. Double the length and you’ll quadruple the wing area but octuple the weight, thereby doubling the wing loading. Ionizing thrusters do have applications on spacecraft, though. ---
**Author:** ![Scott\_Dickerson](https://avatars.discourse-cdn.com/v4/letter/s/f04885/32.png) [@Scott\_Dickerson](https://boards.straightdope.com/u/Scott_Dickerson)\ **Post date:** [September 9, 2003, 6:43am UTC](https://boards.straightdope.com/t/sikorsky-ion-airfoil-why-no-development/200111/5 "2003-09-09T06:43:32Z")
Hmm. I’ll have to do a little more research on previous SDMB discussions of this, but a cursory look at the “ion lifters” cites tells me that there’s some real confusion as to what I’m talking about. The Sikorsky device was not a Bifeld-Brown device, did not involve unbalanced capacitors, and had nothing to do with antigravity. Though I, in my unwashed naivete, would term it an “ion wind” effect, I’m not sure it’s quite the same thing as the phenomena mentioned elsewhere under that label. The Sikorsky device consisted of a lightweight rigid framework mainly composed of a horizontal metal screen–like a window flyscreen–with several short vertical metal “spikes” extending upward from its top-facing surface. When current was fed into these spikes, charge was emitted into the surrounding air. The charged-up air (I think just a very small percentage of the total volume of local air) then rushed downward, attracted to the opposite charge on the screen below, knocking forcefully against other air molecules along the way and creating a substantial downward flow. The moving air then passed on through the open screen, depositing its excess charge along the way. Though the article doesn’t make it too clear, I gather that upward thrust comes from (a) the negatively-charged emitter-spikes being repelled upward by the negatively-charged mass of air below it; and (b) the positively-charged screen being attracted upward by that same air-mass, which is above it. I don’t think comparisons to scaling-up wing area, etc, really apply to something like this. The photo of the model in operation showed it fairly high in a hangar. “Ground-effects” do not seem to be involved. As I recall, it was about a yard square. What I’d really like to find out about is what happened to, specifically, the Sikorsky project, which was being pushed by Igor Sikorsky himself (then a very old man). Maybe a good biography of IS would supply my answer, hmm? ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [September 9, 2003, 2:19pm UTC](https://boards.straightdope.com/t/sikorsky-ion-airfoil-why-no-development/200111/6 "2003-09-09T14:19:31Z")
It was called the “Ionocraft”. Here’s the original article from Popular Mechanics. It appears to be based on the more or less the same principle as the other ion-propelled models that were being discussed. [Major de Seversky’s Ion-Propelled Aircraft (as appeared in the August 1964 Popular Mechanics) - An ion-generated wind will lift and propel this incredible magic carpet of the future - By Hans Fantel](http://mars-news.de/ioncraft/markwilson/page2.html) Parts of article below - > [@](#): > > WAS DOWNRIGHT SPOOKY. Without a sound, the peculiar, spiky contraption rose straight up, hovered awhile, climbed higher. Then it did a few graceful turns, stopped again, and just sat there silently in midair. It seemed like levitation- some trick to overcome gravity. I couldn’t shake off the feeling that I was attending a kind of spiritual seance, or maybe a Buck Rogers Show, instead of an engineering demonstration. > > ## The eerie scene took place in the big, barnlike laboratory of Electronatom, Inc., a research firm in Long Island City, New York, devoted to the development of a new kind of flying machine. I had been invited to watch a scale model being put through its paces by remote control. What we saw was by far the oddest aircraft since the Wright Brothers motorized kite. It had no prop. No jet. No wings. In fact, it had no moving parts at all. Looking somewhat like an old-fa shioned bedspring, the rectangular rig is the nearest thing to a magic carpet. It needs no runway, takes off vertically and is expected to climb as high as 60 miles. It can crawl through the air like a snail, or go faster than a jet. Nobody yet knows its speed limit. > > In their mad rush from the ion emitter to the main grid, the ions bump into neutral air molecules-air particles without electric charge. The terrific wallop in these collisions hurls a mass of neutral air downward along with the ions. When they reach the main grid, the ions, being negative, are trapped by the positive charge on the grid. But the grid has no attraction for the neutral air particles that got bumped along. So the air flows right through the open grid mesh, making a downdraft beneath the Ionocraft. The contraption rides on this shaft of air, getting it’s lift just like a helicopter-by sucking air down from the top. > “Aerodynamically, it works just like a chopper,” Yorysh summed it up. “But instead of using a rotor and blades, we create the downward airflow electrically by means of an ionic discharge. The ions act on the air like a man tread ing water. They just push down.” > > The engineers working on the Ionocraft are the first to admit that their present rig is still a long way from any kind of practical aircraft. The model we saw measures only 1296 square inches and consists of about $5 worth of balsa wood and aluminum wire. But the principle holds an important promise for the future of aviation. > > The problem now is improving efficiency-getting enough lift from a given grid area and a given amount of energy. Present models cannot yet lift their own electric generators. The get power through a feeder cable, dangling down like an umbilica l cord. Ionocraft engineers tend to be close-mouthed on performance figures, but they will tell you that at present it takes 90 watts (30,000 volts at 3 milliamperes) to fly a two-ounce model. Translated into ordinary power-to-weight ratios, t his works out to roughly .96 hp per pound, as compared with a typical .1 hp per pound of helicopter or .065 hp. For a pound of Piper Cub. ---
**Author:** ![Scott\_Dickerson](https://avatars.discourse-cdn.com/v4/letter/s/f04885/32.png) [@Scott\_Dickerson](https://boards.straightdope.com/u/Scott_Dickerson)\ **Post date:** [September 12, 2003, 5:48am UTC](https://boards.straightdope.com/t/sikorsky-ion-airfoil-why-no-development/200111/7 "2003-09-12T05:48:24Z")
De Seversky, huh. No wonder “Sikorsky” looked wrong. So: anyone know of a good De Seversky biography, or other source of info on what happened? (Or didn’t?) (It occurred to me that, if the “ionocraft” really worked, it could be used to accelerate payloads thru the atmosphere and into orbit. Tom Swift and His Atomic Ionocraft, anyone?)