Ligeti Stratos

[Guest Marius Grobler]

Thanks for that Macnoz and palexxxx.Makes you think. An 80 hp 912 Rotax uses about 15 litres an hour at cruise, so a 20 hp engine would use say 4 litres per hour ?

 

....90 knots at 4 litres per hour !!!

 

.

The solution to the energy crisis?

 

 

[Guest High Plains Drifter]

The solution to the energy crisis?

Hmmm... Perhaps we need to approch the Prime Minister for some funding for the Stratos crew - its an ecologically sound mode of transport :thumb_up:

 

 

[ronsky]

Well According to my calcs.....

 

The efficient cruise T vs D on the Stratos occurs at 85Kts. Where Drag = thrust if you require for example 18hp to achieve efficient cruise, it doesn’t really matter wether you run a 45hp engine or a 24 hp engine. Difference in Fuel efficiency between one engine and another is fairly marginal for a set horsepower. It mainly has to do with drag and prop efficiency.

 

I think eventually we will see Light Personal Aircraft powered with electricity. I was going to write a paper for the Australian International aerospace conference next year on the feasibility of electric LPA. But I just don’t have the time ie: Stratos work and testing a new lifting body design. In short electric brushless motors run at 80+% efficiency petrol motors about 4% the latest lithium cells in current development will have a far greater energy density to mass and discharge rate compared to today’s cells. Phantom works has an electric plane that is tested and works on current technology (which will get better). I think Lockheed? or one of the other companies is developing an electric UAV that should fly non stop for around 3 years on the latest Boeing multi spectrum solar cells and lithium batteries. When I pull my finger out and get a Stratos into the air I will eventually look to go electric.

 

PS if you could put in a good word to Mr Rudd for me, it would be appreciated

 

 

[Guest High Plains Drifter]

Therese Rein's Father (ex RAAF) was an aeronautical engineer.

 

 

[ronsky]

Hmm Labour Governments in the past have supported Australian aviation technologies. Getting a foot in the door might be the hard part?

 

PS: I went to Ballarat air museum, Judging by the repairs it looks to be the second MKII Stratos Mick Parer tested.

 

 

[ronsky]

I'm mistaken Ballarat does have the Second Stratos which was the one Charles tested and passed away in.

 

Last weekend i gave a talk at Holbrook airfield on the history of the Stratos. Holbrook Ultralight Club had a fly-in. An Ultralight museum to celebrate early australian ultralight designs will be built there. Anyway Bryan Gabriel restored a production plug of the second Stratos and it is on display there. I have to say that the restoration he did was first class. It looks brand new and has a greater amount of detail in it then the Ballarat one (finish is not as good and has missing parts). If your near Holbrook and want too see how a Production Stratos would have looked like out of the showroom, it's worth checking out.

 

 

[shags_j]

These are pretty impressive stats

 

Ligeti Stratos: World's first open source aircraft

 

 

[Guest TwooDoggs]

From my limited exposure to these two aircraft, I offer a few minor corrections....Actually it was the MK-2 (production) version that crashed.

 

Stories say that it entered a deep stall, tumbled and went into the ground flat, inverted, killing the pilot via head injuries.

 

The airframe was not damaged badly, and was restored, which is the aircraft shown in the last photo's.

 

Remember, this is the MK2, the original prototype was/is still airworthy, and still owned by the Ligeti family.

 

Aerodynamicist discussions point to a change in wing dihedral/anhedral layout from the original which led to greater 'blanketing' of the rear wing during the stall that induced the deep stall.

 

As corrected by Ozzie, the UltraBat was actually based on the Sapphire.

 

The story goes that George had a Sapphire, and was busted doing aero's in it (at the time I think he also owned a Victa, which he aerobatted) so he funded Swanell and Scott to build a fully aerobatic Sapphire.

 

The UltraBat depicted in the link Ultrabat is actually one of about four (I think) that were produced in the U.S. until George and the Americans could no longer see eye to eye. i_dunno

 

The original (only Australian) UltraBat never had a canopy, and was powered by a Rotax 532, a range of motors were used in the U.S. versions.

 

Arthur.

The Ultrabat (VH-ANT) is now powered by a Rotax 583, yes 583, 60 HP+. It is not just Americans who don't see eye-to-eye with George!!! :hittinghead:

 

 

[Guest Maj Millard]

Anyone remember Craig Catto's 'Acro X' which was a further design to his Cunard Goldwing ?. The ACRO X had the similiar fwd fuselage of the Goldwing, but instead of the single low swept- wing, there were two wings bi-plane style half the span of the Goldwing, joined solidly at the tips with enclosed rudders.

 

The lower wings had pronounced anhedral, and the upper pronounced dihedral, so view from the front they looked a bit like an 'X'. As the wing-cell was also cross -cable braced, the thing had to be almost unbreakable. It also had a sleek fully- enclosed canopy over the cockpit. It looked a bit like a galatic star ship, and very futuristic.

 

He only built one example that I know of, and I think he may have taken it to Oshkosh that year.

 

After his return to California, whilst out flying, the canopy came loose, flew off , and lodged against the cables on one wing, rendering the aircraft uncontrollable.

 

Fortunatly Craig was wearing a chute that day, and wisely bailed out. He described the remains as only being bits of foam, and scraps of F/glass.

 

He was busy at the time designing and building wind turbine blades (more $$) and I don't think he built another Acro X. We have him to thank for our efficient large wind turbine blades.

 

Last I heard of him, he was in the air race scene competing in a Cassult.

 

I called him up one time for a propellor, he asked me what engine, and what the plane looked like (an original design). The prop I recieved a week later was within a degree of being perfect for the combination.

 

I thought the Acro X had a lot of potential, pity, like the Stratos, it came and went.

 

 

[Guest Maj Millard]

Brentic, that design looks real interesting, like it should go real quick, but still capable of slowing down good for landing with the right flaps etc. Most delta's have good flareability once the angle of attack comes up. Would a little 1/3 size stabalitor look out of place atop that tail, just for that added stability/controllability. ?. By the look of the specs they've thrown out the Subie and gone to the 912s. I'm interested, lock me in Eddie.

 

 

[Aironet]

To know more about Stratos

 

I would not use the control surface layout of the MKII because of the elevator for stalling reasons. I am opting to use the prototype control surface setup for various reasons, with a mass balance at least on the elevator.

Yep the MKII did stall at a far greater magnitude then what the prototype would stall at low air speed, hence why it caught my father off guard, i remember he was also below 500ft as per CAA regulations at the time.

Dear Ron, (firstly I want apologize for my english - never learn it in school)

 

I saw Stratos photo few years ago and I like it from first time, although of Your father accident. I allways looked for any info, but couldn´t find so much until now, although

 

I must admit that I have some jumble in it. Please, could You explain some things ?

 

How much of Stratos was built - proto, MKII, production ? Was any built and owned by somebody other than Your father or Mick Parer ? Could You write some history of changes (airfoils, chord, sweep, AOA of wings, dihedrals ... ) and flight chars of Stratos versions ? Was tested Stratos stability against stall, tumble, spin ? Please, could You place more detailed photos to Your pages (work of ailerons, flaps, elevator, winglet) ? On web is written "first open source aircraft" could plans be obtained or bought ? What composit structure is used in wing (spar, box) ?

 

Many questions, I think it could be interresting for every Stratos fan,

 

Kind Regards, Jiri

 

 

[Guest rocketman]

Ron,

 

the US website (Google searched for the Stratos) refers to the Stratos drawings being made available through an "open source" site. Is this the case? Is anything happening with getting the aircraft into production? I can still remember seeing the Stratos on "Beyond 2000" way back when 2000 was a long way off. I was impressed then and still am by this aircraft.

 

Neale.

 

 

[ronsky]

Hi Neale,

 

I have decided to not open source the design. I was going to do it properly through universities because they have access to the CAD and other design tools and could use the aircraft in their thesis and studies as a real application of their skills usefull for industry job placment. Everyday people could add to it but few would be usefull because they might not have the skill set in the tools, fellow industry proffesionals would be good value too. The Australian universities said it was nice but did nothing. Also the person i partnered with was not what i thought. I said to myself F-this i have developed the aircraft enough on my own to do it myself. The good news is that personaly i am set up to begin in ernest and i have no more excuses for not being able to move forward. Right now im not publicly voicing what i am currently doing, i'm just going to do it. The manufacturing end plan you are asking about is to license the design out to manufacturers who want to expand their aircraft models. There is a business plan for a mutual low risk solution.

 

Hope this answers your questions.

 

 

[turboplanner]

Good luck with it Ron, you've studied and worked hard enough - you deserve the success.

 

 

[Guest rocketman]

Ron,

 

PM sent to to you for your consideration .

 

Neale.

 

 

[ronsky]

Thanks turboplanner

 

Neale

 

I will have a look into this.

 

 

[wanabigaplane]

Once upon a time

 

Once upon a time..

 

While sub-linoleum reading in a spate of procrastinating the building of my zenith, I came across a copy of the very last issue of Pacific Ultralights. An article by Angela Smith in the magazine detailed the accident at ’98 at Mangalore, where, after George Markey prop stared his Ultrabat, the aircraft got away and gave a young girl in the crowd some minor injuries. George made the point that although there were dozens of people there taking photographs, no one came forward to help him stop it. The photograph shows the Ultrabat after the incident with a broken undercarriage.

 

Quoting the article, “The Ultrabat was purpose built in the Sates to perform aerobatics and was brought to Australia in April ’97.” “George was the founder of the AUF and the first elected president.”

 

Also, quoting elsewhere in the magazine regarding the ’98 Natfly at Narromine, “We said it was going to be the largest ultralight event ever..” “..over 200..” “Immediately evident was the large flock of Jabirus..”

 

Now that was in ’98. I first went to Mangalore back in around ’86, and fell in love with the Sapphire. As soon as I could find the $17,000 it would be mine. I also talked to Charles Ligeti, and saw him fly his Stratos. It was not very long afterwards that both he and Scott Winton had fatal accidents, and I decided to take up something less dangerous, like hang gliding. However, that was new too, self-regulation was in its infancy, and I was deterred by seeing the carnage out at nearby Lake George in a light Easterly breeze one afternoon. The hang gliders were OK, but I could not see how I would survive the learning process.

 

Jack. :):)

 

 

 

 

 

 

 

[batesey]

George made the point that although there were dozens of people there taking photographs, no one came forward to help him stop it.

Hi Wanabigaplane,

 

It's an interesting comment. I was actually at Mangalore that year, I think I was 17/18 years old at the time and had had my pilots license for a couple of years. I was in the Australian Air League at the time and you would see us guys in the blue uniforms guarding planes along the tarmac. I had finished my duties for the morning and got back into my casual clothes, met up with a mate of mine Chris and went for a walk along the flight line to look at all the planes.

 

The ultrabat took both of our attention right away. The pilot was getting the Ultrabat ready for the demonstration. Both Chris and I were standing right behind the plane when the pilot stated throwing the prop to start it alone. I called from across the fence to see if he wanted my assistance. I explained that I was a pilot and could in fact help and it was dangerous to start it by himself. I must have looked to young, he refused my help. He could not get it going, so I offered 2 more times, on the third time he actually told me in no uncertain terms to "p%$# off". I looked at Chris and said, "this is gonna end bad."

 

The pilot looked to really open the throttle (after many failed attempts to start it) and then threw the prop. That was it; she fired up at full power, blew the guy on his XXXX, charged off down the tarmac. It hit a stone, made a 180 degree turn and headed right for Chris and me . All I remember doing was turning to Chris and yelling RUN! There were people all over the place on the tarmac trying to pounce on the tail to stop it. Chris, I and a crowd of others scattered looking for shelter. We hid behind a hanger and when I looked back, the plane had changed course. It was now heading towards 36 on the taxiway narrowly missing Martin Hones Karatoo, before it made it to the runway, it hit another stone and that's what made it career into the crowd...the rest is history.

 

 

[Guest Qwerty]

Did you get a chnce to say something to the pilot afterwards?

 

 

[batesey]

Nope.

 

 

[Guest ozzie]

 

onya George!

 

 

[planedriver]

Thank God it did'nt have the prop at the front, as it went into the crowd.

 

A couple of chocks would'nt have gone amiss either.

 

However, we can't undo whats already been done.

 

At least you tried batesey, you obviously could'nt do more than that.

 

 

[ronsky]

The new Stratos website is at www.lgtaerospace.com

 

 

[Guest burbles1]

That's an attractive website Ron. Are you getting much interest from aero engineering students?

 

 

[farri]

At the time,I followed the progress of the Stratos through our AUF magazines and was shocked to read about the accident.

 

From memory,it was reported that the aircraft was being test flown at 500`AGL,appeared to slown right down then roll over.

 

Was the real cause of the accident ever determined?

 

Frank.