ronsky

Wow, they are some really nice words Mike. I reckon he would have appreciated what you said. You pretty much summed it up right, there is more to the story - but its technicalities and setting the scene as to why he believed he had to take certain risks. He did tweak the second aircraft with the elevator sizing and the channel wing (experimental high lift devise), anyway it caused the second aircraft to stall like a conventional aircraft. Charles didn't expect it because the original Stratos didn't have a pronounced stall. If he was testing at 3000ft i imagine things would be alot different today.

Hey Dave, With me it starts off with a joke of "what if", It usually turns serious later because it turns out to be actualy feasible I saw a Czech jet engine for gliders. with around 500N each. As is a 50Hp ducted fan should already push the Stratos over 120kts. the jets should do better at altitude - have to check the sums 80Liters would require a serious fuselage mod. Do-able though. If a better high temp material than inconel for the turbine was made affordable then you wont need 80L of fuel The fuselage is interchangable with the wings for another option Either way i like the option for bolt in fueltank & prop swap over. Up to the individual Right now for me a 50hp ducted fan - later on jet or even electric

Hey Dave, I actually joked about this with a friend. Yes its impractical, yes its inefficient, yes everything else - but how cool would it be I figured i can run twin (small size) jet pods - one either side of the fuselage where the current engine is via an internal engine mount to the firewall, with a new f/glass tail cone fairing where the old motor used to be. Basicaly allowing you to convert the existing aircraft to a jet overnight, because the fuel tank, fuel lines and engine mount can be unbolted and swapped over fairly quickly - then back again. (you wont need to make a second "jet specific" aircraft) I figured if you play with the config & tank size you can get 1/2hr to 1 hr flight time. if those jet engines can acheive an EGT of 1300C and increase the compression ratio, then it would be efficient and not as thirsty. But current materials available for the price tend to melt right now. Anyway, enough talk more build :-)

To burbles1, Thanks for the feedback, although im not really aiming for eng students. It's just a porthole for people to get info on the Stratos and a way to publish my own info directly, instead of second hand through someone else where mistakes with info can occur.

Hey Frank, Thanks very much for the kind words, its something a long time coming and would be really profound for me when accomplished. Anyway, back to work :-) Will update the web page with construction info in future cheers Ron

To Farri, The accident, was on the second version of the Stratos. The aerodynamics were modified from the original Stratos. the elevator was longer and there was a prototype high lift device that used prop airflow across a channel wing either side of the fuselage to increase the overall lift. All this was because the engines were weak at the time and Charles wanted to increase the rate of climb. Ok the short version is that the stall propogation was uniform across the entire canard causing a more pronounced stall (prototype Stratos stalled the inboard section of the canard with the use of elevator, increasing the AOA locally in that area, the original Stratos had a safe bobbing stall). the high lift devise on the second Stratos would not have helped the stalling properties. In the end the second Stratos stalled more like a conventional aircraft and Charles was unprepared for it and too low to recover. Also from memory the crash occured in an area that was known to have a higher amount of sink rate. There is more to it in the lead up of the accident and with the technicalities that contributed to it also, this is the basic version

Your right dazza 38, it was beyond 2000. around the start of 1987 The fundamental problems arose in the aerodynamics of the second Stratos, the one in holbrook is a plug of the second Stratos The original Stratos - the one you see flying in the video still exists in storage If anyone is interested a new website for the Stratos is at www.lgtaerospace.com

The new Stratos website is at www.lgtaerospace.com

Thanks turboplanner Neale I will have a look into this.

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.

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.

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.

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

Thanks Arthur, that is really nice of you to say. No need to be sorry it’s just the way it panned out, we all meet up again in time Yeah, you are right that would occur, If the stick axis is placed back to where the hand is, it should alleviate any PIO. Charles put a side stick control in to the MKII, but I’m not sure how much space he had around the control hand. I might visit that. Thanks for the welcome Ron

I agree I think there are limits to designs as well, That’s interesting the website changed since i first looked at it. The pictures at the bottom are of a swept flying wing, the delta is new. I try not to critique other designs at concept stage because they usually morph – ironing out the bugs after their inception, stall speed and elevator effectiveness are two concerns on the first design. There are flying wings that work well. Hopefully these guys will do their homework, If they do it properly they can get an efficient flyer - be it modified a few times. I’m weary of Xplane it is a good analysis tool but, I don’t trust it on non- conventional designs for a number of reasons. I lean towards scale R/C models, if you correctly modify airfoils etc for Reynolds number and use a similar power loading, it can show a great deal more, Rutan did most of his work this way. I know guys who professionally model aerodynamics. They use industry standard programs and they still don’t fully trust them. I know of a few issues. The original Stratos is an airworthy reference piece I use to check against, it also holds a sentimental value to the family, maybe one day we might put it in a museum or something. I’m confused? I double checked with one of my aerodynamics books, inertia coupling is a multi axis gyration that occurs on supersonic aircraft. Charles would dive the Stratos to Vne at 270Km/H where the Vne limit was due to engine over-speeding. He did not report any stability problems. Compressibility effects don't occur at that speed. There was an inertia effect on the elevator when hitting turbulence, my father mentioned that he had to mass balance the elevator to get proper stick free stability by neutralising elevator inertia. Stick fixed stability was reported to be fine. He balanced the MKII elevator, he didn’t have time to go back and mass balance the prototype elevator. 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.

Hi DJPacro, Yeah was good to catch up - thanks. I have some stratos video i converted to MPG. i'll try to post it soon and send you the link.

Thanks Tezza, I did abit of flying mainly Cessna's and some gliding. I havent flown much recently due to other commitments, I'm planning to do some flying out of Moorabin soon. Lamborgini of the sky, havent heard that one - it's quite flattering and a credit to my father. I actually didn't know about the Ballarat museum display. I want to see it soon. if it was the one my father passed away in i might pay homage to what happened and examine it to see if theres anything else i might learn from the second aircraft.

That looks like a nice design. I always liked flying wings from the Horten designs to the B2 and the new Boeing BWB experiments. Northrop had a number of designs. I know one had a nasty stall that sadly killed the test pilot. If i remember correctly they named “Edwards†airforce base after him. If done correctly they can fly well and be super efficient. I believe the Boeing design tries to ease the stalling by using the forward fuselage as a lifting body, giving a canard stalling effect, be curious to see the results. If the EGGENFELLNER wing sweep and angle of incidence is done right it could be a real go-er!

Hi ,I just joined, my aviation background stems from child hood, my grandfather was an aviator in the war, also my father designed and built an aircraft called the Ligeti Stratos, his friends would take me up flying in ultralights, GA aircraft and Gyrocopters as a child. I thought it was great fun and interesting so I chose pursue a career in aviation as an aerospace engineer.

Mick Parer crash A friend sent me a link to this forum I am writing to elaborate on what happened After my father Charles Ligeti crashed the second “highly modified†Stratos claiming his life, the company decided to make another aircraft, keeping the bad aerodynamic changes to the aircraft then adding more changes. The aileron linkage setup was changed causing increased aero-elasticity in the ailerons. The duct on the original Stratos ran a 3/16†tip gap between the prop and duct. There was a ½†gap on this aircraft. Due to the nature of ducted fans and how they work, would cause at least a 20% reduction in thrust on an already underpowered design. The following occured. The aircraft takes off at Mangalore airport flying level with the runway, altitude of about 2 meters, right wing noticeably lower than the left against the horizon. The aircraft slowly straightens wings level, with the engine at full throttle the aircraft barely gains altitude, running out of runway Mick turns right, mid turn - wing angle of around 30 deg the sound of the engine cuts out, immediately the aircraft sideslips and hits the ground, after the right wingtip strikes the ground it rotates the aircraft around to finally rest. Aircraft noticeably damaged, relatively intact but unfixable to test. (Mick Parer later reporting the ineffectiveness of the ailerons and lack of power). If requested I can elaborate on the “highly modified†aerodynamics of the second Stratos, specifications of the original Stratos that flew successfully and details of a new aircraft.