FAR rules on "ground-effect" vehicles?

I think that is the point. It looks like someone is trying to infer that the Wright Flier is not an airplane because it
never left ground effect....

--
Dan D.



..
"Todd Pattist" wrote in message ...
Big John wrote:

If your vehicle won't be able to fly out of ground effect (and you
don't plan on flying over water) where will you fly it??? I don't
think ground effect goes up and over obstructions (houses, trees,
water towers. electrical power lines, etc).

Where would you use the vehicle and how? Fly point to point around the
airport vs using a golf cart?

Maybe it would make a fun, ground-effect only, preliminary
flight trainer :-) If it won't leave ground effect, it's
not an airplane.

Todd Pattist
(Remove DONTSPAMME from address to email reply.)
___
Make a commitment to learn something from every flight.
Share what you learn.

(BllFs6) wrote in message ...
Hi,

found a few old WIG links last night....

these have pics of WIG hovercraft flying....

http://popularmechanics.com/outdoors...ts/print.phtml

http://www.hovercraft.com/

http://www.se-technology.com/wig/index.php


I used to have one pic showing a WIG hovercraft about 10 feet above the ground
doing a "hop"....bet it felt like a hundred feet to the operator though!

WIG hovercraft appear to have many problems....airborne stability for
one....another, dealing with mirror contacts with ground or water (waves)
without it turning into something resembling that bad landing they used to show
at the begining of the 6 million dollar man episodes....


I am not an expert on this topic but I have seen WIG hovercraft in
operation and talked to their designers.
The idea behind this design is that the aircushion makes final
break-away from the surface easy, with very little drag at the
transition. Also, touch down is very smooth.
As for wing tip contacts with water, it does not seem to be very
upsetting. The tip shapes dictate that the contact is only with the
trailing edge.
These things are cool to watch but they are mostly just a stunt,
in my humble opinion because they are slower than the hovercraft they
are derived from. Plus, they are naturally more wind-sensitive than a
hovercraft.
One reason that the hovercraft community keeps looking at WIG
technology is that light hovercraft start to fly away from dynamic
lift effects around 55-65 mph. That has been an upper speed limit,
unless one is willing to pile on weight. High performance hovercraft
can accelerate to 60 mph from a dead stop in under 10 seconds (
precise measurement is nearly impossible. Maybe with a calibrated
video camera)
That performance comes from having static nearly equal to empty
weight.


Another problem is variation of weight.....you need to make sure you CANT get
truelly "aircraft" airborne at minimum load, yet you still want to be a decent
height above the surface at maximum load....so it may make more sense to NOT
make the thing as light as possible as you would an aircraft....so that the
percentage difference between min load and max load is significantly smaller
than that of a true typical aircraft....

which aint neccessarily bad...becuase if I built one of those suckers I'd put
in a heavy duty roll cage that protected me, my neck, and ensured that I
floated upright and intact when (not if) I wrecked the thing and it ripped
apart in spectacular fashion!

Sure, that way the drag is more than if you made it as light as possible, BUT I
bet you would still be going alot faster with much less energy than you would
in an equivalent boat! And the ride would be smoother...at least until you
crashed....

The CD reduction is .8 at height = .25 wing size, .6 at .15, and .5 at .10 the
wing size...where IIRC size = chord...though it could be span....and at height
above ground effect CD = 1.0

So you can see you need to get pretty close to the ground for the WIG effect to
help much...

I'll email you the graph I have

take care

Blll

WELL, this certainly has turned out to be an interesting thread...

Let me make a few more clarifications:

First, I was not trying to infer anything about a Wright 1903 or later machine.
Not the point... not even close. 1903's, 1904's 1905's, etc are definately and
emphatically airplanes.

Second, the original "flying machine" that I am thinking about reproducing was
built in 1907. At best, a reproduction would be limited to straight-line
demonstration hops of less than 1,000 linear feet down a runway, closed road,
cow pasture, etc.

Third, I was reminded not so long ago that the original designer's son asked me
not to try to fly an accurate reproduction of this machine if I ever built one.

Therefore, I think I have found my angle... Its got 3 wheels, it does not use
public roads, and it will not fly. Therefore, it SHOULD be possible to
classify it as an ATV, rather than an aircraft, even though it does have
"wings". That takes 1/2 of the fun out of it, but maybe I could compensate by
making the engine louder or something.

Sorry that this thread wandered so far off-topic.

Harry

(Wright1902Glider) wrote in message ...
WELL, this certainly has turned out to be an interesting thread...

...

Therefore, I think I have found my angle... Its got 3 wheels, it does not use
public roads, and it will not fly. Therefore, it SHOULD be possible to
classify it as an ATV, rather than an aircraft, even though it does have
"wings". That takes 1/2 of the fun out of it, but maybe I could compensate by
making the engine louder or something.


Well if you find out that your state regs on ATVs are too burdensome
then maybe you can get the FAA to classify it as an experimental.
It surely won't be the first experimental aircraft to not get out
of ground effect. I'm sure lots never got off the ground at all.

--

FF

FF:

Oh, that would be wayyyy to easy. Did I mention that I do not have a PPL yet?
Currently, the concensis is to go with the ATV classification, and stuff in the
biggest, meanest, loudest, loudest, loudest V-twin engine that I can find. Did
I mention that I'd like it to be loud? And maybe I can channel all of that HP
into a 36" prop or something. Did I mention that loud is good? Oh yea, and as
long as it isn't going to actually fly, it should probably be really loud.
That, and the extreme scariness of the design, may be all it has going for it.

Harry "ancient obscure aircraft" Frey