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VL3 fast ultralight


johnm

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Empty weight 270Kg !!? In their dreams maybe. It would have to be made of tissue paper to get that weight realistically. My Legend is 313Kg empty and you can see how hard the manufacturer has worked to get it to that weight.

 

 

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VL3 - World's fastest UL aircraft2 seat side by side - 165 kts ! max cruise - rotax 912 or 914 - 450 kilos ! max all up weight

MCR01 'VLA' (Sportster

 

General characteristics

 

Capacity: 2

 

Length: 5.4 m (17 ft 9 in)

 

Wingspan: 6.63 m (21 ft 9 in)

 

Empty weight: 235 kg (518 lb)

 

Gross weight: 450 kg (992 lb)

 

Powerplant: 1 × Rotax 912, 60 kW (80 hp)

 

Performance

 

Maximum speed: 318 km/h (198 mph)

 

Cruising speed: 300 km/h (186 [11] mph)

 

Stall speed: 80 km/h (50 mph)

 

Range: 1050 km (652 miles)

 

 

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my understanding is Europe ultralights are designed to 450 kg

 

but they are capable of 600 kgs to cater for USA and Oz legislation ?

 

................. something along those lines

 

 

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my understanding is Europe ultralights are designed to 450 kgbut they are capable of 600 kgs to cater for USA and Oz legislation ?

 

................. something along those lines

Some are, but not all. The Euro ultralights can go to 472kg if they're fitted with a recovery chute. The recovery chute gives them an extra 22kg of weight limit with a penalty of about 15kg for the weight of the chute, so they only get 7kg extra payload capacity.

 

 

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there's plenty of google material where the Euro designers claim that the 450 / 472 threshold limits what they can achieve

 

I imagine say Tecnam and your Legend craft fall into this category Csot ? - they are designed for either market and flown at 450 in Europe and say 600 in USA / Oz ............. is that a fair summary ?

 

 

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there's plenty of google material where the Euro designers claim that the 450 / 472 threshold limits what they can achieveI imagine say Tecnam and your Legend craft fall into this category Csot ? - they are designed for either market and flown at 450 in Europe and say 600 in USA / Oz ............. is that a fair summary ?

Yes, the Legend was specifically engineered for the 600Kg market and is flown in Europe at their weight limits. But that is not a given with all UL aircraft coming out of Europe. My previous airplane, the Nynja was designed for the European UL market, but wasn't engineered or tested for 600Kg and so it can't be registered as an LSA anywhere. I'm not sure what the status is for the Tecnam, but I'd be sure there are pre-LSA Tecnams out there that could not be re-registered as LSA because their original manufacture didn't account for that extra MTOW. Later models could possibly be so, but if an aircraft is registered as a UL here, and someone is hoping to re-register it as an LSA, that's a whole different thing. I emphasise this last point as when I was looking for an airplane to upgrade from the Nynja, I had a couple of people try to sell me ULs saying that they could be upgraded to LSA. I enquired about that and it isn't a straightforward paper shuffle as some sellers would have you believe.

 

 

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There was some shonky stuff going on about 10 yrs ago where importers were getting 600kg rego on their aircraft and when casa did an audit on raa, found they were not really certified for 600.

 

I believe a manufacturer can say they are structurally sound at 600 but if there is no certification then it is invalid for raa rego, or something like that.

 

The Allegro aircraft had their weights reduced and I think some 24 rego aircraft had to go to 19.

 

 

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that would not be a nice paperwork thing to discover

 

the thing that interests me is that you have say an empty 280 kg plane that is legal in Europe @ 450 kilos - 170 kilo useful load

 

in USA or Oz its say 600 kilos - same plane ? - 320 kilo useful load

 

................. but essentially the same plane ? ........... something doesn't seem right

 

 

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There was some shonky stuff going on about 10 yrs ago where importers were getting 600kg rego on their aircraft and when casa did an audit on raa, found they were not really certified for 600.I believe a manufacturer can say they are structurally sound at 600 but if there is no certification then it is invalid for raa rego, or something like that.

The Allegro aircraft had their weights reduced and I think some 24 rego aircraft had to go to 19.

The issues as I understood it was not the manufacturers, but the importers. The importers were registering the airplanes at 600Kg when the manufacturers hadn't done the engineering nor testing at those weights.

LSA is what is known as a declarative standard. The manufacturer has to certify that the aircraft have been designed, manufactured and tested in accordance with the ASTM standards (or the European equivalent). The manufacturer is then responsible by law that those declarations are true.

 

In the early days of LSA, the importers were making these declarations and when CASA looked into the manufacture of these planes, they found that the manufacturers hadn't certified them. There is a form 681 (and some other forms to go along with that) that the manufacturer has to fill out and sign, stating that their manufacturing and testing complies. If there is no form for the aircraft, then it can't be legally registered as an LSA.

 

the thing that interests me is that you have say an empty 280 kg plane that is legal in Europe @ 450 kilos - 170 kilo useful load

in USA or Oz its say 600 kilos - same plane ? - 320 kilo useful load

 

................. but essentially the same plane ? ........... something doesn't seem right

Yes, it doesn't seem right. Even with carbon fibre technology there is a limit to material strength and the lighter you make the plane, the less strength it has. As I mentioned, my Legend is 313Kg empty and the MTOW is 600Kg. The fuselage of my plane is quite strong but I wouldn't want it to be much lighter.

Having said that, I've been advised that the manufacturer has moved to pre-preg cloth that does reduce weight without compromising strength. That may account for some of the 33Kg difference between this aircraft and my Legend, but I'd bet you'd find some very thin (read light) pieces on this plane. A couple of areas where my Legend is quite thin is the wheel spats and other cosmetic pieces. The problem with pieces being so thin is that they flex, but the paint doesn't. So we've had some paint issues. It's only cosmetics, but it is a little disappointing.

 

 

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that would not be a nice paperwork thing to discoverthe thing that interests me is that you have say an empty 280 kg plane that is legal in Europe @ 450 kilos - 170 kilo useful load

in USA or Oz its say 600 kilos - same plane ? - 320 kilo useful load

 

................. but essentially the same plane ? ........... something doesn't seem right

It's mostly about what countries and regulating bodies consider to be the separation point between "ultralight" and a "real" aircraft.

 

MTOW (and stall speed) is a way of regulating and defining that point.

 

Also remember carbon fibre, computer simulation and such are new technologies allowing the strength without the weight and generally the regs have been in existance many years. So it is possible now to build an aircraft that can hold it's own weight...

 

 

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that would not be a nice paperwork thing to discoverthe thing that interests me is that you have say an empty 280 kg plane that is legal in Europe @ 450 kilos - 170 kilo useful load

in USA or Oz its say 600 kilos - same plane ? - 320 kilo useful load

 

................. but essentially the same plane ? ........... something doesn't seem right

It's mostly about what countries and regulating bodies consider to be the separation point between "ultralight" and a "real" aircraft.

 

MTOW (and stall speed) is a way of regulating and defining that point.

 

Also remember carbon fibre, computer simulation and such are new technologies allowing the strength without the weight and generally the regs have been in existance many years. So it is possible now to build an aircraft that can hold it's own weight...

 

 

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So it is possible now to build an aircraft that can hold it's own weight...

That's a very interesting observation. I never thought of it like that.

I believe there is a practical limit on engines which is around the 1HP / Pound. I wonder if there's a similar practical limit to the load carrying capacity of a structure.

 

Something interesting to consider is that if the wings are rated to +4 -2 g, then they are carrying far more than their own weight, even in a conventional structure.

 

 

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I was really sceptical at first knowing that undercarriage is a huge drag on an aircraft. Then I remembered the Q2. It has its undercarriage in it's wingtips, much less drag. Just looked up the Q2 specs, not that far behind this aircraft. Given that the whole aircraft could be made from carbon fibre, I think that the weight could be lowered so much that a lightweight engine such as Rotax, may give close to the weight as is with this aircraft. I have not done an engineering study on this, I just using my mental arithmetic on general items. I do not believe the VNE though, the spars, even in carbon, would have to be strong and heavy. Why have such a high VNE, probably would not get there even in a dive.

 

 

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I can see that there is some confusion on this subject

 

Back in 2000 factory built Ultralights required a Type Certificate (TC). The original Australian manufacturers were required to go through an expensive certification process. There was no system in place to allow the importation of foreign factory built Ultralights. The only possibility was for CASA to formally visit the factory of the manufacturer and approve the aircraft for Australia. CASA issued a NPRM calling for submissions allowing foreign factory built ultralights.

 

This new rule came to pass in 2002 with the proviso that a foreign TC must exist for the foreign factory built Ultralight. At that time Australian ultralights could only operate to a MTOW of 544kg. Most of the Ultralights with a TC in Europe had a MTOW to fit in with the different European weight restrictions, usually around 450 kg. The AUF at the time issued Type Acceptance based on the documentation and TC submitted. The CASA audit identified aircraft that were not adhering to the original TC’s. It is correct that some Ultralights were built to a higher MTOW and in a number of countries including Australia and NZ, this was 544 kg. All importers were required to submit documentation from the manufacturer supporting a higher MTOW. A number of importers were unable to produce this documentation and the MTOW of these aircraft was restricted to that off the original TC.

 

Ultralight certification should not be confused with LSA. The FAA introduced a simpler form of aircraft certification in September 2004, in which:

 

'The manufacturer is responsible to certify the aircraft and the continuing airworthiness. This means that the manufacturer certifies that each aircraft complies with the LSA standards by signing a statement of compliance. The statement of compliance must indicate that the aircraft was manufactured by a qualified manufacturer, complies with the design and performance, quality assurance, production testing (not required for a kit aircraft) and continued operational safety monitoring standards’.

 

LSA allowed a manufacturer to nominate a MTOW of up to 600 kg with the manufacturer assuming full responsibility for the ongoing airworthiness of the LSA.(Whereas CASA has a responsibility for factory built Ultralight aircraft because of the Type Certification of those Ultralights.

 

In 2006 CASA enacted an Australian version of LSA with a 600 kg MTOW. Not long after that RA Aus allowed a maximum MTOW for Ultralights of 600 kg. There was some confusion in the technical guidance from RA Aus at that time and some owners and importers of identical Ultralight airframes began operating at a MTOW of 600 kg. This was identified in the CASA audit of RA Aus and TC’s or documentation from another countries National Airworthiness Authority approving operation at a higher MTOW was required of the importer or owner. Most LSA are now designed with greater strength to allow for the higher MTOW.

 

Ultralights approved to operate at 600 kg MTOW were required to alter the ASI, lowering the indicated VNE and VNO speeds.

 

On the subject of manufacturer empty weights, to meet a MTOW of say 450 kg or less, most manufacturers had a minimal aircraft is available which is essentially a stripped out shell. no heater, no upholstery, no trim, limited fuel capacity, smaller wheels, two stroke engines, minimal electrics, the most basic seats, simple hand brake, etc. that is how the mythical figure of 270 kg could be achieved whereas the same airframe destined for Australia included every possible option including a personal bidet!

 

With regard to future RA Aus increases of MTOW, these will not apply to LSA aircraft unless CASA changes the regulations governing LSA. The weight increase will allow homebuilts and GA certified aircraft,with TC’s that fall within the new MTOW, to be registered as Ultralights with RA Aus.

 

 

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Look at the specs for the MCR01 'VLA': The wing span and wing area of the 450kg version is far too small to carry 600kg and meet the LSA stall speed criteria (maximum stall speed in the landing configuration (Vso) of 45 knots CAS). Most LSA carrying 600kg have a wing span of 9m or more. Now add the bigger wing, stronger fuselage, undercarriage etc and your empty weight will be much closer to 300kg, like all the others. And the speed has come down to the level of a current very fast LSA (125-140kts on 80hp).

 

 

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If a complex wing with slots and le slats one could possibly get the velocity range. Use laminar wings and you would be close. I still believe that it is possible. Very expensive with carbon fiber and nylon printed parts instead of steel parts and it would be a very light aircraft. Owing to the higher wing loading it would be more stable in turbulent weather.

 

Are slats and flaps allowed to obtain a low landing speed, or must the wing loading be without, I don't know?

 

 

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VL3 - Fantastic looking aircraft but looks dont make it fast.

 

What is it about aircraft manufacturers performance claims. They may be true, they may not, but one thing for sure they never seem to keen to subject their aircraft to independent evaluation.

 

To the best of my knowledge there is only one manufacturer that has repeatedly entered a Rotax powered factory (ultralight) aircraft to the NASA CAFE(Comparative Aircraft Flight Efficiency) Challenge and won each time.

 

This (& similar independent evaluation) is the only performance data worth talking about the rest is just wishful thinking.

 

"Handsome Is As Handsome Does"

 

 

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Are slats and flaps allowed to obtain a low landing speed, or must the wing loading be without, I don't know?

Like you, I'm not totally positive about this, but I thought the minimum stall speed was stated as the no flaps and MTOW speed.

 

 

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To get high speed with low landing velocity I have many times played with the idea of extending wings. A smaller wing that fits inside the cruising wing. Using honey comb wing section on the cruise wing and the wing extension running on rollers with cable controlling it's location. But I have never gotten past the design of a sparless wing. It all seems a little too heavy. If anyone has any great ideas for such a wing please let me know.

 

 

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I find it astounding this aircraft has a MTOW of only 450kg, yet has retractible gear, parachute, 2 seater, full leather upholstery, room for 4 airline bags, yet a stall speed of only 28kts and cruise of 165kts. Must be 1st of April..

 

 

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