Wing In Ground (WIG)

Telephone poles come to mind!

Actually, it is not a bad idea over water where terrain is pretty constant.

I was going to say, Ships, but telephone poles is pretty funny. Ask the Russians. They have some large WIG transport aircraft.

Of course, trees, houses, etc prevent any practical use of WIG machines on land. Over water, waves can be a problem, unless the wingspan (and therefore the permissible altitude) is quite large. On small bodies of water, maneuverablity is a problem, if there are other craft in the area. A very steep turn puts the craft partially out of ground effect, leading to possible wing dipping and loss of control. The high speeds that are required for WIG flight combined with large turn radius means there is a serious limit to where the craft can be used safely.

For some applications, they can be appropriate, but, like hovercraft, I believe their use will always be limited, unless one can engineer in far better controlability in turning and stopping.

Don't you need a pilot's licence once your vehicle ceases contact with the earth's surface?

Quote: "Don't you need a pilot's licence once your vehicle ceases contact with the earth's surface?"

No, I've seen many cars doing just that and I don't know of anyone being given a ticket for flying without a license ;-)

Actually, yes, I believe you need a pilot's license for 'driving' any machine designed to leave the surface, e.g., hovercraft.

I'm pretty sure you dont need a pilot's license to fly ultralights, and those can supposedly fly to around 10,000 feet.

Let's remember that this is an international forum. Laws may be different in each country. In the USA, a FAA license (called an Airman's Certificate) is necessary for powered flight if the aircraft exceeds certain fuel capcity, weight, top speed, and other specifications. Here is the complete information from the Wikipedia:
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The USA FAA's definition of an ultralight is significantly different from that in most other countries and can lead to some confusion when discussing the topic. The governing regulation in the United States is FAR 103, which specifies an "ultralight" as a single seat vehicle of less than 5 US gallons (19 L) fuel capacity, empty weight of less than 254 pounds (115 kg), a top speed of 55 knots (102 km/h), a maximum stall speed not exceeding 24 knots (45 km/h), and are only allowed to fly during daylight hours and over unpopulated areas. Weight allowances can be made for two-seat trainers, amphibious landing gear, and ballistic parachute systems.

In 2004 the FAA introduced the "Light-Sport Aircraft" category, which closely resembles other countries' Ultralight categories.

In the United States no license or training is required by law for ultralights, but training is highly advisable. For light-sport aircraft a sport pilot certificate is required, which is similar in requirements to other countries' Ultralight license.

There is a good article on ultra-lights in the Aug "Popular Mechanics" mag. In it, they reference Congress's looking into regulating this "sport flying".

In my country (South Africa), a "Micro-light Pilot License" (MPL) is a requirement for all types of ultra-light flying. Even motor-less hang gliders require a form of license to pilot over here.

In the US, no pilot's license is required for class A and B craft. (Class A are those that cannot leave ground effect; class B craft can "jump", but cannot sustain flight out of ground effect. )

As a pilot, I am naturally nervous when in close proximity to the ground -- that is, after all, where nearly all the crashes occur. Close proximity to the water makes me even more nervous, because when you touch down, the drag is so much higher. Neverthless, I designed a sailboat that had the potential for operating in ground effect -- although I never implemented the features that would permit such lunacy.

At one point I had this craft going 32 knots (fairly fast for a sailboat, but not world record speed) and found it almost terrifying, even while in contact with the water. (You may say "What a wimp!" but I am someone who has flown aerobatics, jumped off cliffs in hang gliders, and raced motorcycles at 150 mph. I suppose part of my anxiety had to do with concern for the prototype as much as concern for my own health.) As you can guess, drag would decrease dramatically upon liftoff, with just a few vertical foils in the water, so speeds could jump from terrifying to higher pretty quickly.

A couple good pages on WIG -- if any of you are unfamiliar with the craft, you'll find some fascinating stuff:
http://en.wikipedia.org/wiki/Ground_effect
http://www.se-technology.com/wig/index.php

And a large pair needed

I always thought some sort of hybrid wheeled WIG assist system trending to total WIG mode for long runs would be interesting for large area crop spraying applications. The local air turbulence is an asset in this application as it enhances spray penetration of the canopy. Also a large long span structure is already required to carry the application equipment.

Wing in ground effect is a very overlooked effect that can increase safety in all airplanes and seaplanes when properly designed. By combining several surfaces with the right aspect ratios and position one can make the pitchting moments with respects to height neutral to positive, instead of negative which is the case on most "conventional" designs, such as the Lake, SeaWind, Adventurer, and float planes. The air under the wing works at the center of area as the wing gets close to the water. This creates a negative pitchting moment compared to free air where the pitchting moments are taken around the 25% of chord point, making the airplane pitch into the water more strongly as the plane decends. This is NOT what should happen. It should be neutral to slightly positive, but NOT negative. When the plane is neutral to positive it can be flown close to the water without diving into the water, allowing for a lot more FUN in skimming the water. If it is positive, it can be trimmed to height and flown hands free just above the water. A neutral pitchting makes for good land landings also, and will reduce Pilot induced occilations caused by ground effect. In fast airplanes, it could eliminate "mach tuck" and perhaps the need for fly-by-wire tech, making the airplane supersonic and afforadable. It can also make an airplane safer in ice conditions, depending on design of dependent systems, of course. So, by looking and addressing WIG issues, one can make a much safer airplane, even supersonic airplanes at a fraction of the price.