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karoliina

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Posts posted by karoliina

  1. Anyway, all of our electric vehicles are necessarily small, and have very expensive Lithium-polymer batteries if they cary their own power, or are tethered to batteries on the ground. Still, a typical battery charge will only last about 5 minutes when the motors have to produce enough power to lift the vehicle through thrust alone. Very impractical.

     

    It is not entirely so, actually (not commenting this specific company and its design, but in general), when high amount

    of power is required, standard batteries are not the way to go. Actually there are more advanced methods such as hydrogen burning cells etc. The technology is coming to small portable equipment already - one can run a laptop with methanol very much longer than with any conventional battery, the process goes so that part of the methanol is converted to hydrogen and the cell converts the hydrogen to electricity. That is the way of the electric cars of the future as well, conventional batteries have their limits and they are not suitable everywhere.

     

    I do not comment ducted fan VTOL designs, but in general,

    I think an airplane engine could be replaced with electric engine if there would be hydrogen cells of sufficient power on board (expensive, but not necessarily so heavy). The hydrogen cell causes quite much zero pollution and is very efficient and with a brushless electric motor it would be extremely reliable).

     

    We have two electric cars in our household and they are using

    those conventional batteries, no hydrogen cars in our household yet, someday, potentially yes.

  2. Yes, indeed, the Diamond turbodiesel plane is very nice.

    If money would not be an issue, I think I could buy

    a brand new Diamond DA-42 Twin Star and be happy.

     

    I have been thinking of dual engine Cozy where the engines

    would be Thielert turbodiesels (the same as used in

    the Diamond). That is of course easier said than

    done as it would require the engines placed to the wings instead of

    back. Anyway, for me, a three to five place Starship with big

    tanks full of Jet-A1 would be quite much

    a dream machine. Actually I have been also thinking that three

    seats plus a mini-toilet would be very nice, I think I will never

    really need more than three seats. When flying with my

    partner, the other one of us

    could pilot the aircraft while the another is in toilet :).

    That way long trips without landing could be feasible, otherwise it

    is not the need of retanking which limits the endurance but the necessarity

    to go to pee. Currently our TL-96 Star has more endurance (about 5 hours)

    than is the frequency of the need to go to toilet.

     

    I could prefer traditional twin engine configuration over push-pull

    configuration because I have a feeling that it might have less drag.

    I am not completely sure though.

  3. Hi,

     

    In addition to the Vari-Viggen plans I mentioned before, I am now looking

    for Rutan Vari-Eze plans as well. If you have them, please e-mail

    me, my e-mail is karoliina ät karoliinasalminen dot com

    (please replace the ät and dot with the proper characters).

     

    Best Regards,

    Karoliina Salminen

    Finland

  4. Hi,

     

    Yes, Starship is made of quite 100% carbon with Nomex honeycomb core. Not the cheapest materials around, but has good weight/strength ratio.

     

    My current plane, TL-96 Star (is called as StarSport in USA), is made of mainly fiberglass and the wing spars are made of 100% carbon. It seems

    to work that way.

     

    The teacher at aircraft service and maintenance course that I am attending

    told that it is common to put one layer of glass on top of a carbon part.

    The carbon can not be sanded or it will lose its strength, so he said it is

    good to put one layer of ligthweight glass on top of carbon to avoid

    damage to the carbon when finishing the outerior of the part and also in use the glass on top of the carbon protects the carbon below from impact

    damage that the carbon is not good to withstand. He had an example of

    carbon structure there for demonstration,

    it was a such Nomex honeycomb sheet which had

    carbon on top of it (it was from MD-11's floor if I remember it right).

    Little hit and there was an ugly hole in it.

     

    I had a chance to sit in the cockpit of a very nice Airbus

    yesterday by the way at Finnair's maintenance.

    The flight simulators tend to give that kind of impression that

    the visibility from the cockpit of such passanger aircraft would be

    quite limited, but it could not be more

    wrong. The visibility out is excellent (allthough not as good as in my plane

    which has a full transparent canopy of course)

    when the seat is adjusted right and

    the ergonomy to the side stick and other controls is very nice. The side

    stick looked very much like the Infinity Aerospace's stick. The aircraft

    is 100% fly by wire. V-nice...

    Pity that I am not allowed to fly a such thing...

     

    Best Wishes,

    Karoliina

  5. Yes, indeed, same boat and stuff and I think I will propably do the same if/when

    I proceed with the actual building...

     

    I have actually downloaded the Aerocanard plans.

     

    First, prior doing a canard aircraft of some sort, I will do a new

    engine cowling for my current plane (TL-96 Star) which

    I purchased a short time ago. The current shape is not aerodynamically

    ideal and I am investigating if I could replicate the shape of TL-2000

    Sting's cowling and do my own similar one therefore to the Star

    (I would use that for training of the epoxy etc. use). The engine

    cowling happens to be one of the places which can be (heavily)

    modified by the owner despite the plane is a factory built one (not a kit,

    but still it is an experimental anyway).

     

    I noticed that there is no importer as far as I know for MGS epoxies

    in Finland. Hmm. Maybe, should I become one? The customer base would not

    be great, but...

  6. Hi,

     

    I noticed that the MGS epoxies are approved by German aviation

    authorities. They appear to be suitable for aircraft use indeed.

    Good to know.

     

    How about the glass material then:

    What type of glass cloth is being used in Cozy?

    Specs (strength), weight per square meter, apparently it is E-Glass rather

    than S-glass etc.? There are plenty of options available already here

    in Finland ranging from 48 g per square meter up to heavy stuff.

     

    Really interesting thing what I just heard by the way is that

    Cora (microlight) was done from polyester resin instead of epoxy some

    years ago (I have been participating a service and maintenance

    course where I heard that).

    When the Finnish guy did some repairs with epoxy, they

    said that it is unapproved material and don't meet their quality requirements.

    Instead of believing that, the Finnish guy had said that they should

    consider switching to epoxy. After all, they did... Another thing

    that I also noticed, Woodcomp fiberclass Kremen propeller was

    made of Norpol 440 boat polyester resin. That is cheap yes, I have

    20 kg of that and it costed about as much as 2 kg epoxy, but the strength

    is not very nice especially considering that it loses strength after +30C

    temperature.

     

    Best Wishes,

    Karoliina

  7. Hi all,

     

    There have been a lots of talk against deviations from the materials

    described in plans. However, the plain fact is that

    there are dozen canard projects in Finland and only one of them

    is flying and have proven to be successful. Not because of the

    material, but because of other things. However, the interesting thing is that the only Cozy which is flying, is not made of Ez-Poxy or other approved

    materials but from vinylester resin which was not purchased from

    the US stores like Aircraft Spruce. I have talked with the guy and he have

    said that the hardest part was that there was no exact data available

    about the Ez-Poxy and he had to prove the stiffness by other means.

    If someone has exact specs of Ez-Poxy (including all strength

    etc. parameters), I would be grateful to see them. Ez-Poxy is not

    necessarily the world's best aircraft material and there might be some

    european alternatives which would rival it or be even better than the

    original Ez-poxy. To be able to do the research, specs are needed.

     

    Also about the glass used in the Cozy project, which are its parameters

    including weight per square meter?

     

    Best Regards,

    Karoliina

  8. There is no specs for e-racer anywhere where I know.

    If you can tell me the exact weight etc. details of a standard e-racer,

    I would be glad. E-racer is designed for 160 hp or more engine as

    far as I know. The deal here with the friend would be to try to design a canard

    which works fine with Rotax 912 UL (80 hp), 912 ULS (100 hp) or

    Rotax 914 (115 hp turbo) and weights no more than 250-260 kg as empty

    and has stall speed lower than 65 km/h.

  9. At least you could try something with X-plane.

    http://www.x-plane.com

     

    It is an aerodynamic simulator which evolved into a flight simulator and

    it is available for Windows, MacOSX and Linux.

     

    I have a book called Aerodynamics for Engineers. That was supposed

    to be the easier choice of the two kind of bibles in this area. Still, the

    mathematics there is very hard to interpret even with an engineer's

    background. The book is full of very complex integrals. It is about

    aerodynamics in general and not just about canards however, I don't

    know if there would be some simplified text somewhere out there.

    Maybe someone else more informed might be able to help.

  10. Actually if I elaborate more, the discussion with the person who

    had the idea was:

     

    - The material would not be the same than in original

    - The engine would be a Rotax 912 UL instead of the original

    - The weight would be heavily reduced

    - It would be made to stall under 65 km/h

     

    In other words, not a Vari-Viggen, but a Ultra-Viggen. It would

    be quite different to control than the original heavy version as this

    thing would be aimed to weight around 250 kg including engine and

    in no circumstances more than 275 kg including engine and avionics.

  11. I am not sure if it is in a wrong place. I assume that it has

    something to do with its very slow stall speed of 65 km/h.

    If you look the side picture what it reminds the most?

    To me it looks distantly like giant fowler flaps. Unlike other

    canards, Bateleur is STOL (short takeoff and landing) aircraft

    and can be operated from unimproved airfields unlike other canards.

    It is still very fast to be a microlight (or Finnish term class B ultralight) and

    it is also lightweight if compared to other alternatives such as TL-96 Star

    which is near to the upper limit of the allowable weight in Finland.

    Because I am not rich, in the mean time (before a plans built canard project of

    any kind can be finished as it takes formiddably long time), here is

    a picture of the bird I am thinking of buying now:

     

    Posted Image

    (One of the alternatives)

     

    Posted Image

    Another pic

     

    No near a canard performance, but ok in the meantime.

     

    Specs:

    - 180 km/h IAS (cruise), about 200 km/h IAS max (realistic) level speed (I have tried and it does not go faster), but goes easily 250 km/h in dive

    - Vne 275 km/h

    - Empty weight 285 kg including instruments

    - Full composite structure

    - +4/-2 G

    - Rotax 912 UL 80 hp

    - Stall speed without flaps 80 km/h

    - Stall speed with full flaps 65 km/h

    - Does not enter spins easily and stalls softly

    - High glide ratio

    - Two place with dual controls.

    - Fixed pitch three blade carbon fiber propeller

  12. Hi,

     

    It was explained some time ago here why two stroke

    engines are not suitable for aircraft use. I don't remember

    exactly what was the reason, but the two stroke engines

    weren't suitable for traffic pattern like use. It has something

    to do with RPM and the oil lubrication which was lost

    in certain conditions in a traffic pattern no matter how well and carefully the engine would have been serviced and managed.

    Despite of maintenance, they are generally considered

    unreliable here. Quite much all of those who have flown

    those early day ultralights (microlights) with two stroke

    Rotax engines, have done at least dozen forced landings.

    It just isn't very good figure. That is why even class A

    ultralights, in other words the Trikes are mainly equipped

    nowadays with four stroke engines and no-one wants to get

    into a plane equipped with a two stroke engine.

     

    Br,

    Karoliina

  13. Hi,

     

    I would not recommend using Rotax 503 in any design.

    The four stroke version 912 UL weights more but is zillion times more reliable and has 80 hp power and 1500 hour rebuild-cycle.

    My former flight instructor has some experience on the two stroke

    Rotax engines in regards of european microlights.

    He have done about 20 forced landings with the old two-stroke microlights and

    none with the newer stuff which is analoguous to USA SportsPlane

    category except that there is no upper limit for speed unlike in USA, can

    be as fast as possible as long as the stall speed can be done with high

    lift flaps or some other way down to 65 km/h or below.

    One of our flight clubs flight instructors was giving a presentation

    what they did with ultralights (in some other countries called microlights)

    in 1980s. They fixed the engine in the morning and for the end of the

    day they did a forced langing or two. They measured a mean catastrophic

    failure rate for the two stroke engine that 1 start per 50 starts at least

    will lead to forced landing. With one person canard equipped with

    two stroke Rotax, you can get yourself killed in less than 50 hours

    in other words (if you don't succeed in the forced landing and walk away

    alive).

     

    Where you need the single seater as the two seater

    RMT Bateleur would do the task nicely and billion times more

    safely, wouldn't it?

    Posted Image

     

    http://www.rmtaviation.com

     

    Equipped with either Rotax 912ULS (100 hp) or Rotax 914 turbo (115 hp),

    the aircraft has exceptional performance in the ultralight/microlight/SportsPlane (choose your term depending on country)

    category.

     

    I thought that RMT Aviation would be out of the business because their

    e-mail bounced back, but the trick was to resend the question and

    on the second try it did work. They are offering a info-DVD for 10 EUR.

    I am going to order it.

     

    The specs for Bateleur are great.

    - 450/472.5 kg (EU) MTOW (without/with BRS)

    - Stall speed below 65 km/h

    - Cruise speed 270 km/h IAS with turbo Rotax

    - Fuel consumption, autogas 12-14 liters per hour.

     

    Miles per gallon ratio unbeatable. You can fly really fast with

    a minimum amount of gas.

     

    Bateleur is available as a quick build kit as well (in addition to being

    sold as a complete aircraft). Its price tag is rather

    high, but carbon fiber + microlight + canard is an equation where

    the result is not cheap. One could build a fast build

    Velocity with the same price or less.

     

    Look at the canard incidence by the way:

    Posted Image

     

    Interesting design, isn't it?

     

    Best Regards,

    Karoliina

  14. I asked about Velocity's profiles from Velocity. They did not know it in details something like "There is no number for them, they were designed by a NASA engineer". Starship is also using some

    (laminar flow?) NASA profiles.

     

    Mika, did I understand it correctly

    that you are either designing or going to

    design own canard aircraft or otherwise interested design

    a such thing?

     

    I would be very interested doing an own design (I have

    had that dream very very long time, even before I became

    aware that it could be possible, for many years I thought

    it would not be possible for an individual with limited

    amount of money and resources) allthough

    there is are several big problems:

    before that would be feasible, it is

    quite much needed to do some other design first to understand

    what an aircraft consists of and that is going to make several

    years to accomplish. And secondly think I need to study

    some more mathematics as the mathematics present in the

    book Aerodynamics for Engineers goes beyond my understanding

    with my current level of understanding in higher math.

    And thirdly I need to do first some radio controlled scale down

    models and try to figure out in depth how X-plane's aircraft editor

    works - to try things with the sim.

     

    Best Wishes,

    Karoliina Salminen

    (Espoo/Finland)

  15. Yeah, I did notice from Internet that MEKP is rather

    bad stuff. I am using gas mask, two layers of gloves

    and try to not get touch with the substance. I noticed

    that it is really bad for eyes as well, I need to protect the

    eyes apparently as well to play safe - and most importantly,

    no food in the same place where the MEKP is used...

  16. Hi,

     

    Because I am totally inexperienced with glass fiber works, I purchased several days ago a 20 kg canister of

    polyester resin (cheap), 1 kg hardener, 5 kg mold release agents,

    some glass fiber cloth and some foam (cheapest I found).

    I am not going to build an aircraft from this material as it

    has not aircraft strength and weight properties, but I am

    using it for training to do this stuff. I have never done

    anything like this before and I need to start training from

    somewhere. Now I am preparing to do some horns for

    loudspeakers from glass fiber and the spherical horn mold is

    nearly ready (I made it from wood using a lathe).

    And a cat sand box (that is

    where I need that foam because it will be a moldless composite

    sand box). And, nearly forgot, I purchased also a gas mask.

    I don't want to destroy my brain cells because of the fumes.

    Lets see how long I need to work on this phase before I can

    give myself green light for ordering Cozy plans - I need to

    try first if I can learn to do this on the first place with high

    quality required for aircraft components

    before starting the project because

    I don't want a project that never finishes so I need to

    try things first before starting the actual project.

    Preparation are everything, aren't they?

     

    Best Wishes,

    Karoliina

  17. Hi,

     

    So a solution could be the following:

    - change the wing and canard airfoils to a such that handles better high speeds, I think the modified Eppler may not be good for

    high speeds. Some NASA laminar flow airfoil could be used instead of the Roncz/Eppler combination?

    - Use stronger materials in canard construction such as

    carbon fiber.

     

    But now what - what we get: kind-of Infinity-1 (allthough a four

    place version)...?

     

    Yes, I have visited Greg's web page, that is where the idea

    came from (I had been thinking that already by myself,

    but did not think it would be possible until I saw Greg's page)

    - Cozy can be used with a jet engine. Now how

    fast it can go with a jet engine is the question and how to

    determine how to modify it to make it better suitable for

    the jet engine.

     

    Best Wishes,

    Karoliina

  18. Hi,

     

    Has anyone of you bumped into these:

     

    - RMT Bateleur: Ultralight canard.

    URL: http://www.rmtaviation.com

    It is a EU ultralight canard / USA SportPlane.

    Stall speed less than 65, max cruise 270 km/h with

    Rotax 914 turbo. Pretty awesome for being light aircraft.

    Weights only 259 kg.

     

    - Gyroflug Speed Canard:

    Try googling Speed Canard for some info. The kit is

    discontinued as far as I know, but looks pretty interesting.

    Some Finnish pilots have flown Speed Canard.

     

    Posted Image

     

    Best Wishes,

    Karoliina

  19. Hi,

     

    Why the Vne of Cozy is 220 mph?

    If someone would use a jet engine in Cozy instead of

    piston engine, this could become a serious limitation.

    What detail in the airframe limits it to 220 mph?

    Could it be modified to allow higher speeds somehow,

    for example by adding more strength in certain parts?

    Many Lancairs have higher Vne than Cozy. What makes

    it dangerous to fly Cozy faster than 220 mph, is it expected

    that the airframe can not handle greater speeds and tears

    apart?

     

    What I have tried with X-plane is that the virtual Cozy can

    fly a lot faster than 220 mph. But what about the real Cozy,

    what happens when flying faster than the 220 mph limit,

    for example in the case of jet engine?

     

    Best Wishes,

    Karoliina

  20. Hi,

     

    I have been thinking how the canard concept could be

    improved further. The latest material and engine developments

    might help to achieve something further from Cozy/Velo/etc.

     

    The latest material developments are interesting. There

    is a Finnish company called Nanolab systems which

    is specialized in carbon nanotubes. With nanotubes it

    could be possible to reduce the weight dramatically if

    compared to the traditional composite materials.

    The link to Nanolab systems is here:

    http://www.nanolabsystems.com/

     

    Another interesting technology is emerging in the engine

    side. It is called Z-motor and invented in Finland.

    The Z-motor does has similar efficiency than a two-stroke

    engine but has the reliability of four stroke engine - it

    is a four stroke engine. It means achieving reliable

    high horse power with small weight, something that sounds

    great for an aircraft engine.

    Link to the Z-motor company Aumet Oy is here:

    http://www.aumet.fi/

    As usual, the problem with this kind of things is the lack

    of funding and interest in the car industry. But how about

    aircraft industry? Sounds very interesting at least to me.

     

    I am having a image of a two place Cozy-variant which has

    flaps (Starship-like flaps),

    has stall speed of 62 km/h, weights 285 kg...

    Actually the Z-motor invention is a diesel engine, so it

    would use Jet-A1 instead. Alternatively how about six or eight

    place Cozy variant (home built)

    which would resemble Starship and

    would still weight just the same as the original Cozy...??

    There are many possibilities the lighter weight could

    cause not to speak of the current design which could be propably

    made lighter even with the current materials by reducing

    weight carefully from places where it is not really needed.

     

    The carbon nanotube composites might not be very cheap

    at the moment, but it is not going to stay like that forever.

    They are coming sooner or later and then even carbon fiber

    can be considered as heavy material.

     

    Best Wishes,

    Karoliina

  21. ~$35/hr for a subaru powered minamally configured version to ~$80/hr for your standard IFR equipped Lycoming version.

     

    Interesting that IFR thing is because in Finland it is not possible

    to use any experimental aircraft in IFR flight. Only factory built

    aircrafts can be certified to IFR flight here as far as I know - one

    can equip his/her aircraft for IFR flight, but can't fly with IFR plan

    (in other words, not even fly over clouds if there are no substantial holes

    in the clouds where the ground can be seen).

    Therefore because the restrictions are that you only fly on

    daytime and below the clouds and with VFR rules (you look

    what is happening around and you are responsible for

    avoiding aircrafts that are not equipped with radios etc.),

    how would that going be successful

    if someone would build a Viperjet here for example? In other words,

    if someone cruises with an experimental aircraft (such

    as Viperjet) at 450 knots,

    I bet that it will be tricky to notice slowly moving aircrafts on

    a ordinary Finnish day when the cloud height is 2000 feet or below and

    one can not see sun anywhere.

    450 knots is 231 meters per second, that is pretty fast for visual observation

    and especially taking account the altitude, e.g. 1500 feet.

    Then the interesting part, the guy in the next door can fly his

    little Cessna 172 with IFR plan over the clouds on the same day

    the Viperjet owner is doomed to fly under the clouds.

    Isn't that a bit odd? I don't know if exceptions can be done,

    for example Burt Rutan's SpaceShipOne would have been registered as

    an experimental aircraft in the case Burt Rutan would have lived here,

    if he would have been limited to VFR rules, wouldn't that been pretty

    interesting to do the whole trip to suborbital space in VFR? Of course

    it can be speculated, that from suborbital altitude one can see ground

    even if there would be continuous cloud coverage there and there.... ;/

    Also it have been so that in ultralights (which are analoguous to

    American VLA or Sports Plane category), the weight have been limited

    to 450 kg and many ultralight aircrafts available here have the weight

    so close the 450 kg limit that a ballistic recovery system can not be

    installed. In Germany it was decided that the ballistic recovery system

    in these aircrafts is mandatory. In Finland, on the contrary, installing a

    ballistic recovery system have been indirectly forbidden (allthough I heard

    that it may be possible to apply for exception, to go over the weight

    limit because of ballistic recovery system) because they increase

    the weight of the plane over the 450 kg limit (allthough in reality,

    most of these aircrafts are structurally designed for 550 kg or 600 kg MTOW

    instead, but the 450 kg limit is printed to their operating manual

    to satisfy authorities). Sorry for going to kinda off-topic about this

    regulatory bureaucratic country.

  22. Hi,

     

    Just as a sidenote, it appears that also

    Bombardier have done work for a new aircraft

    engine. It will be however heavier than the Jabiru suggested

    above.

     

    Anyway this model gives 300 hp:

    http://www.vaircraftengine.com/en/technicalData_v-300t.asp

     

    I don't remember exactly what was the weight limit of the motor,

    perhaps it is too heavy, the turbocharged version weights 210 kg

    which is something like 460 lbs...

     

    Best Wishes,

    Karoliina

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