I think that this plane is ready for next aerotow, IGG Aerotow Rally 2011 @ Jämijärvi next weekend..

I decided to use H-57 as an 'paint scheme'-model as it has no paint . Original is currently located at Karhula Aviation museum. Stickers were done with kind assistance of Stealth117 & printed by Callie.

Btw - I have set up an gallery of pics from 1:1 PIK-planes. It currently includes 4 Harakka II's & plenty other PIK's. Including H-57. See here.

Tuomas

Hi ya all,

I am now (almost) done with finalizing plans. Thing which is still missing is that for *$€£@£*/&% reason I cannot seem to get TCAD to output properly scaled PDF, but when that is solved it's done. If someone has good insights an pm is appreciated.

I will put this plan to public domain, ie. it will be freely downloadable, along with laser-ready cutting templates from my webpage.

Bitmaps of current situation are included below.

Tuomas

Some further developements are under way.

- so called 'muna-harakka'. (direct translation is egg-magpie . This is actually an additional shell to fuselage which is secured with magnets & screws. See pics.

- 1/3 and 40% versions of this plane. These will be simple scaling excersises with no structural changes. There is couple teams of youngsters building these. This will be fun...

Tuomas

Did some scaling to get some more exotic size planes. I only scaled plans, I did not change texts, nor adjust structures to suitable wood sizes. So IF somebody ever will build these he must make some changes & design new way of attaching wings. 13mm graupner brass tube is not sufficent in this size .

Now I have 3 more plans....

- 1/3 scale, wingspan is 3,37m
- 40% scale, wingspan is 4,05m
- 50% scale, wingspan is 5,26m

That last one I did just for fun. That is serious piece of flying wood. The wing chord is 68cm and area gargantuan 400+ dm2 !!! Fuz height is 71cm, not counting rudd. Wing thickness is 10cm. To save some wood in ribs I 'dismantled' rib into puzzle pieces which could be laser cut. I experimented with part nesting and it really saves 50-70% wood depending scale. With puzzle keys assembly should be breeze.

I guess that 50% really should not be built, as it will be approaching ultra-light sized man-carrying planes.

Below you will find some examples of wood usage. Paper size is 3000 x 850.

Tuomas

That 'egg-shell' is done. I will send it to cutters when I have done another design. Just trying to some €€€ on postage etc.

This design was somewhat complicated, as I could not use devfus or other cae-stuff. But it should be quite easily built. Everything should be locking together, so one could build this in hand. Perhaps.... have to try .

Tuomas

Hi,

after aggressive wrestling with turbocad I finally gave up on it's 'pdf-capabilities'. I solved this intriguing problem in similar manner Alexander the Great opened Gordian knot. I did not use turbocad. It simply does not have needed capabilites. .

I had to use autocad viewer (DWG trueview) to output PDF. And to get plans to viewer I had to export everything from Turbocad to DWG. But then on it was smooth ride. I really must say that turbocad has it's good points, but PDF-output is not among those.

Now those plans are available for everyone, for free. It costs nothing. (or - to be specific, if you manage to build something then pls. send me an photo of your creation).

Plans also include PDF-version of parts templates. So you can use professional cutting services, if you feel that you are not up to task of cutting ribs etc. I can also arrange cutting services, if needed, but it will cost you.

Plans should be ready for printing services, but after all this cad-wrestling there is an possibility of error. So double check scale markings at printshop.

Website address is http://www.iwaru.fi/harakka.html.

Enjoy,

Tuomas

Hello!,

Tuomas, do we see this egg-edition at next week IGG Nastola event?

BR,
Hannu

Egg-edition? (btw - that is one really spiffy name for this aerodynamical plywoood fairing which will transform this ancient flying contraption into modern, super-orchidee-ld-50-or-something... plane ).

Nope, it will not be ready for Kuivanto. I have approx 3 hours free time before that event. And no parts yet. That would be tight.

Tuomas

Hello everyone,

I took Harakka II to Kuivanto Aerotow 20.8 and finally I have had time to compile some videos. I must admit that I get chillies when I try to do some videos, but... My PC is relatively new, but still adobe premier makes it look like snail in frost.

Before videos I have 'final word' on flight capabilities of this thing. We (that is I and some frends) have done ~30 flights with Harakka, and I think that it is my favourite 'take it easy, just relax'-plane.

1. Plane flies great. It is overly stabile, but yet quite agile. It can turn in an dime, but it still flies solid.
2. It does not like crosswind, but still it is quite manageable.
3. Due the low wing loading it is not suited to gale force storms, but it really isn't feather.
4. Yes, you can do moderate aerobatics. Loops - yes, rolls - 'yes, barrels really', stall turns - yes! etc. Just keep speed up.
5. Yes, it thermals quite well. Norm flight last week was 10-15min, longest 20+mins.
6. Under any circumstances do not let it stall in aerotow. That will happen if towplane is slower than Harakka. With today's towplanes it is extremely rare, but possible. Bad things will happen .

It looks kinda funny floating around, but .. judge yourself. Regarding slope, I have no clue. I have not tried this in slope. No slopes here.

Then to videos.

First video contains two short-cut aerotows. Actually landing rounds, but you get the impression. Wind was quite blustery during these, but plane handled well. No problems.

PIK-7 Harakka II @ Kuivanto Aerotow 20.-21.8.2011, part I (HD) (2 min 34 sec)

Second video contains something which Hank must explain. He and Matti wanted badly to fly around field with Harakka in tow. Just many circles, nothing else. I do not see the point of this, but it looks fun. Harakka looks like dog in leash bouncing around. They did it also with 50% KA6...

PIK-7 Harakka II @ Kuivanto Aerotow 20.-21.8.2011, part II (HD) (3 min 39 sec)

Last is mandatory video for open cockpit plane..

PIK-7 Harakka II @ Kuivanto Aerotow 20.-21.8.2011, part III (4 min 1 sec)

I like this plane .

Tuomas

Hello, fellas!

Well, where should I start in regarding experiencies during this season about this lovely bird, maybe it would be better say The Bird

First of all, great thanks to Tuomas letting me fly this beauty during this fantastic IGG - season!

Secondly, it is truly a real performer, it was fantastic to see while Tuomas took a tow somewhere 300m height, and moment later it was over 800m altitude..

3rdly, descending aerotow...

Harakka looks like dog in leash bouncing around. They did it also with 50% KA6...

( KA6 was not looking like that dog)

Well, this was very first training to next weekend Airshow at Kymi...
It is quite tricky to do descending aerotow 360 deg with Harakka, as there is no airbrakes, but now we do have an idea how we will perform this descending tow circles in show.

Karhula Aeroclub invited us there in their annual airshow, as both of our seasons´s favourite planes originals are located there, Tuomas`s Harakka H-57 and my 50% KA-6 OH-242

Hope wheather gets better, its been too many lowpressures moving over Scandinavia this week..

Copy also Tuomas`s comment: I like this plane


BR,
Hannu

IGG Display show team participated Kymi Airshow. We got a lot of publicitity for big gliders as Hank took his big Ka6 and I took my small Harakka. I assume that the number of spectators was over 1000.

I am not going to bore you to death with pics of 1:1 DC-3 doing rounds, Gloster Gauntlet, Fouga Magister, numerous sailplanes, ultralights, one antonov etc. These you can find here. Instead of them I have one of best Harakka pics (again) from Tommi Oksanen.

The reason we got so much interest was that the 1:1 versions of planes we were flying are located at local museum. So in a way we were presenting local history in real life.

Tuomas
ps : Okay, I'll add pic of Hannus 50% Ka6 with 100% version of it.

Hello!

Had a very nice event there, Harakka was a truly show stopper there!


BR,

Hank

Has got to be one of the best gliders build old school I have seen, you attention to detail is amazing. Just love the way you make what is available work to bring this bird to life. And you flying field is just beautiful and the other sailplanes and tow planes were as nice. I really enjoyed watching you build this grand lady. Thanks for sharing.

Great many thanks Rick for your kind words. I do enjoy building..

Just an brief update; I have ordered wood parts for the egg-edition (nice phrase, Hank), I hope that they will be here next week.

Propably last aerotow for this season will be at Selänpää airport next weekend. It will be 2,5 days of aerotow extravaganza, but I do hope that current storm will pass before it. I'll be taking Harakka & Kajava there.

Tuomas

One comment still...

I just noticed that ... if you look carefully that KA-6 pic in message #41 you will notice that 2:1 copy of Hank's KA-6 actually has rc gear.

Tuomas

ps : okay, there is logical explanation. There was an guy doing air-to-ground-photographing and he must have parked his foamy plane & radios behind that 2:1 KA-6.