i got this letter re the WSH-500

Hi David,

We have contacted the Korean company as a buyer.

We requested they show a vidieo with the craft airboane not touching the water or a photo.

They have not been able to provide evidence it in fact left the water.

I can send you the info they provided.

They are trying to sell it for 8 million.



Cheers.

that sounds strange...

But I guess the question is if they really couldn't deliver any evidence or if they just didn't want to. It would be sassy to sell something for 8mio without any evidence of it's airworthiness.

And by the way, isn't the video not enough of evidence?

I guess we have to wait until may to get more info. Hopefully good news.

That low res, shaky video is a weak demonstration of a 8 Million dollar(?) machine. I would need at least a HD video from a helicopter

the video we saw didnt convince me that it was airborne, i at first thought it was a high speed taxi test.

my 2 thoughts against it is that with the wings so close to the water it would need slats like the beriev 103 to keep airflow attached and also with the pontoons so far apart inner wing would probably be heavy to be strong enough to withstand water impact.

it also reminded me of many of our wig models that would not lift off unless it had a far aft cg which then made it too unstable OGE.

this is my model.
in this video it was airborne in about 30 ft and all i did was reduce power to about half stick and did not touch anything else. it remained pretty much at the same height hands off, except when 'stalling'. these turns were all uncommanded. the wind was light.

http://www.youtube.com/watch?v=hSrjl...ature=youtu.be

another view of 'tip stalling' as soon as she lifts off.

http://www.youtube.com/watch?v=Y74yv...5fAUAAAAAAAAAA

Folks – just a note to say that today I have finally got my personal website up and running.
Here you will find loads of photos of my experimental WIG models, together with magazine articles and papers that can be downloaded.

http://www.grahamktaylor.com/index.html

(Only took me three years to get round to this.... please drop me a line of you find links that don’t work or have any other trouble with the site).

Regards

Graham

had a look nice videos. are they really airborne? looks like they touching the water/grass.

The videos of the models over land are all in PAR mode - they are touching the grass, snow etc. because the models have to run very fast to reach full XGE flying speed. If I make a pilot error at that high speed over land I am likely to damage the model badly. I need to be very brave to go to XGE over land (I have done it in moments of madness and when not concentrating) . But even over land in PAR mode the models can move as fast as a radio controlled racing car so I have to keep pretty sharp. Water is more forgiving and a model will survive an XGE crash (usually) but it needs lots of space and a run-up. So the models make a run-up in PAR mode touching the water slightly until they reach XGE. Even then they tend to leave a wake as the wingtip vortices are so close to the water - and then it is time to slow down again before running out of lake.

Originally Posted by captarmour

another view of 'tip stalling' as soon as she lifts off.

http://www.youtube.com/watch?v=Y74yv...5fAUAAAAAAAAAA

That's not tip stalling, that's directional instability. Large flat sided nose with a longer moment arm than the vertical tail surfaces. The large nose acts like a fin in front of the CG, pulling the nose of line and fighting the vertical tail.

Make the nose profile smaller or rounder or move the vertical tail farther back.

Originally Posted by bigjohn

That's not tip stalling, that's directional instability. Large flat sided nose with a longer moment arm than the vertical tail surfaces. The large nose acts like a fin in front of the CG, pulling the nose of line and fighting the vertical tail.

Make the nose profile smaller or rounder or move the vertical tail farther back.

thanks i am proceding with the next model with a tractot engine which will push the cockpit/cabin back to have the vertical surfaces farther back.

the only problem though that OGE it shows no such instability. i tried in vain to upload the videos off my phone but no joy.

the rcpowers hydro does the something similar in the beginning of this video and at 2:44 but at the end where the swept portion of the wing is removed it displays no such tendency.

BIG RC Hydro! (4 min 18 sec)

interestingly the single engined version which prob has a lighter wing loading does not drop the wing like the twin engine model.

RCPowers F1 Hydro 3D (7 min 17 sec)

i think being so close to the water causes the wing to stall due to the adverse press gradient.

the beriev 103 which was designed to take advantage of GE has slats which would most likely cure that problem. its wing is very close to the water as well.

http://www.beriev.com/eng/Be-103_e/Be-103_e.html.

i may be wrong but tip stall may be correct.

cheers

I just suspect directional stability because in the second video I saw the vehicle right after liftoff yaw to the right before dropping the right wing.

Then I looked at the lateral areas and relative moment arms of the "cockpit" area and the vertical fins, which do not look like a strongly stable setup.

I may be wrong as well, but it sure didn't look like you had the angle of attack to cause a tip stall..

Le Navion, prototype de navire à effet de surface (WIG) (2 min 34 sec)

i have not seen this one before. anyone familiar with this wig?

The Wing plan is more like the Aquabird than the Flightship, don't you think? Brave man flying it! There's no cage over the prop.

very brave indeed my friend.

it flies nice, seems to transition IGE, OGE very nicely. the wing/tail ratio is a lot different to flightship with its higher AR wing.

i need to get off my butt and build my next model!