Ekranoplans and ground effect

[Boston]

I saw one come "flying" off a trailer once going down the highway at about 75 mph

they called the highway patrol

thing went sliding down the highway scattering cars the whole way
just happened to catch the whole show
was a mess
tore the external parts of the drive off
thing was real nice to kinda an inboard outboard like set up with all the bells and whistles
didnt roll though just kinda grinded its way down the road until it finally slid to a halt
minus most of one side on the bottom

 

[kroberts]

Aztek, virtually every low-wing aircraft is a WIG during takeoffs and landings. The difference is they have not been optimized for that flight regime but for flying up in the skies.

From the site you have cited:
"WIG-crafts are not aircraft's. Specific design criteria's are complete different compared to an aircraft. For example the take off. An aircraft uses a angle of about 14 degree for maximum lift to shorten the take off distance. A WIG-craft has to be started without this facility. To flare with high speed so low over a surface the have to be auto stable. Over the years different types of WIG-crafts where developed to optimize this type of craft."
With all the respect for those guy's work, these arguments have nothing to do with a legal distinction between WIGs and aircraft.

WIGs are a particular type of airplane, if an airplane is a machine entirely sustained by pressure field induced by the airflow around it.
When flying over a water surface WIGs have to obey to maritime traffic rules.
If they take-off from an airfield and then crash in the middle of a desert, the survivors will not call the Coast Guard to come and save them, I guess.
WIG stands for Wing In Ground-effect.
Wing, birds, airplanes. No wing, no WIG.

This logic is faulty.

A hovercraft is entirely sustained by a pressure field induced by the airflow around it. It is, however, not an aircraft and requires no aircraft certification. It requires a boat license (vessel license, not operator license) and, in some states neighbouring mine, an ATV license if you intend to operate it on land.

Similarly, the car I had before the current one had a wing on it, and if a wing makes an airplane then my car was an airplane. However, it was not licensed as such and could not be used as such.

Every US Code of Federal Regulations entry I have found regarding a hovercraft fits into one of these categories:

1. A statement saying that the vehicle must comply with the defined national and local regulations for the nearest type of use which applies. In other words, if you are on water then it follows boat rules, if you are on land you follow land rules.
2. An explicit mention of hovercraft by name, usually to prohibit something in addition to boats or land vehicles.

You are confusing legal definition with technical definition. Technically, a WIG might be an aircraft. However, if it can't operate in space controlled by the FAA and similar organisations in other nations, then it makes no sense at all to require a license, registration or certification from that organisation, does it? A technical definition is created by engineers and such, but a legal definition is created by lawyers and such.

Crashing a hovercraft is extremely easy. I'm on my second one, and the first one suffered a lot due to the length of time it took for me to learn to drive it. They crash because you haven't figured out how to direct the thrust properly, or how to stop safely or properly, or because you forgot that letting go of the throttle does not in any way increase friction between the hull and the surface of whatever you are operating over.

Contrary to other types, the most frequently damaged part of a hovercraft for beginners is the rudders. You generally can get it turned around after you remember that that's what you needed to do, but you don't always remember in time for the redirected thrust to do much good.

 

[daiquiri]

I know... let's not get back again to the page 3 of our discussion.

 

[kroberts]

Then what part of page 3 were you not getting back to? What point were you making for post 72?

The revisit to this topic caused me to email the FAA through one of their contact email addresses, to see if somebody there can find it.

In Aztek's link which you quoted in 72, it says "Wigs are not aircraft." but then you point out that nearly all aircraft are WIGs at some point. The logic fails, and you seem to be revisiting page 3.

In legal terms, these things are true:

1. In order to follow the law, one must know what it is.
2. If the FAA requires registration, licensing and certification of a particular type of WIG, then of course it must be done.
3. Only the use space really counts for vessel certification and regulations.

This discussion might be abstract for you, but I have a hovercraft which can be easily converted, per plan, into a WIG. This discussion is NOT abstract for me, nor is it theoretical.

 

[daiquiri]

Ok, I realize that this is an important question for you. In that case, I stand behind what I said at page 3. What I said in this page was aimed at easing the tension and making few jokes about it.

As I stated at the page 3, there appear to be a contradiction in regulations (or at least U.S. regulations), because WIGs appear to fall into FAA definition of airplane, the airplane being a particular case of aircraft. Yet they appear to be specificaly mentioned in the maritime and IMO rules, and therefore fall into the maritime trafic regulation.

Please let me know what FAA has replied to you, because I'm really interested to see what regulations do then ground-based WIGs fall into.

And please don't get angry so easily. It is really just a theme for an interesting discussion to most of us, certainly not something our living depends on. I understand your position is different.

 

[kroberts]

Daiquiri,

Not so much "angry" as "automatically serious."

I tend to get argumentative fairly easily too, not necessarily hurling mud although some people don't seem to understand that.

The WIG regulations regarding maritime use seem to be coming from international organisations, which is what I would expect. I strongly suspect that the FAA does not want anything to do with WIG classifications which are not class C. I can't find any mention in the regs, but I recall a news article at one point suggesting that was the case.

Of course, it's possible that my article was wrong, or that my memory of it is wrong.

If you look at the form and intent of laws, the regulations can and do regulate things which normally do not fall into the scope of the agency. For example, a guy flying a kite at the end of a runway will get a visit from some airport official in a hurry, and will also probably get a talking-to from the FAA. The kite does not require a license, but anything interfering with a restricted airspace falls within the scope of the FAA. This includes radio and TV antennas.

Likewise, a cable stretched across a river will fall under the authority of the USCG or any other maritime agency, even though it is clearly not a boat.

In every case, the regulations are written by the agency which controls the space in which the object is being used, not by some abstract definition based on what sort of parts the object has.

 

[aztek]

hi
this is my argument= http://en.wikipedia.org/wiki/Ground_effect_vehicle
Aztek

 

[apex1]

hi
this is my argument= http://en.wikipedia.org/wiki/Ground_effect_vehicle
Aztek

Not a real good argument aztek, because the Wiki article is incomplete and shows a contradiction here:

"The International Maritime Organization recognizes three classes of ground effect crafts:

1. Type A cannot operate out of ground effect.
2. Type B can jump to clear obstacles by converting kinetic energy (speed) into potential energy (height), but cannot maintain flight without the support of the ground effect.
3. Type C are certified as aircraft, with the ability to operate safely and efficiently in ground effect.

GEVs are not aircraft and can be certified as boats."

In a former post I made clear what real life says about this topic.
Regards
Richard

 

[daiquiri]

I have also written some articles for Wikipedia, related to aerodynamics. Anybody can do it. That's how Wikipedia works.
I (or you) could also delete the phrase "GEVs are not aircraft" and write whatever. Anybody can write whatever they want in Wikipedia, as long as someone else don't contradict them.
My general advice (not related to this topic): don't take as unconditional true what you read in Wikipedia. It is not a verified and reliable source of information.

 

[mydauphin]

It is a bird, not a plane or is it a boat. It only matter to local government taxing division. It is a bad boat, and a bad plane. Anyone know a simple WIG design that is easy to build, works simply, and foolproof?

 

[aztek]

hi
Dauphin try a kind of cat but with a low air-ram wing in the middle.
aztek
PS: put the prop/fan at the front to force air under the wing

 

[kroberts]

Richard,

Every source of information on WIG craft states that there is no distinguishable difference between a class C WIG and a seaplane. Nobody denies that class C WIG craft require FAA licensing, as do their operators.

Daiquiri,

You are right that wikipedia is not an authoritative information source, but it does make a good introduction to a subject if you are new to it, and gives you a bunch of keywords and phrases by which you can do a more in-depth search. The better articles have a bibliography, so you can get better information.

It's not so incredibly bad as the anti-wikipedia people claim. The articles are subject to peer review, and if somebody edits it the changes are logged.

Mydauphin, ever hear of a boat design that is easy to build, works simply and is foolproof?