Aircraft selection

I was always dreaming about building my very own aircraft from scratch. I've started doing paragliding and powered paragliding recently, but the idea of my own aircraft was still waiting somewhere in there. It's clear that creating my own design is out of my current capabilities, I'm an electronic engineer, not an aircraft designer. Therefore I've started browsing available designs that would meet the legislation in the Czech Republic, had plans-only option available and wouldn't cost me a kidney and a liver. These are the requirements I came up with:

  • Two seats.
  • MTOW below 600 kg (ultralight/LSA category limitation).
  • MTOW minus Empty weight greater than 225 kg (ultralights in Czech Republic have such limitations - it must be able to carry two 100 kg people plus fuel for 1 hour of fligh on full throttle). This requirement unfortunately ruled out a lot of good looking constructions.
  • Build from plans option, or a reasonable priced kit (the kits are usually quite pricey and the shipping from US isn't the cheapest).
  • Lower stall speed/STOL like characteristics (possibility to use short airports).
  • High wing or biplane (love biplanes!)
  • Simple construction - no welding (except maybe landing gear) required - would need to get licensed welder to do it legally, which isn't the cheapest way, or maybe get someone to weld it for me.
  • Lower fuel consumption
  • Reasonable engine option - don't want to spend 25k USD just for 100 hp Rotax,...
  • Folding wings option (nice to have).

Possible options

Spacek SD1/2

SD1

The aircrafts from Spacek are pretty capable, high cruising speed, very light, interesting construction with foam ribs, etc. The build process is well documented and the Spacek company is located not that far from my place, so it's not a problem to discuss issues that would appear during the build process. They don't make STOL aircrafts, but I do like the construction and it's performance.

Unfortunately the SD1 is a single seater and the SD2 is available only as a kit or a finished airplane and the kit price is comparable with other kit aircrafts mentioned here, therefore a bit to expensive.

Druine D5 Turbi

Druine

The Turbi is a very interesting aircraft, there are quite few of them flying, it can be built in both closed cockpit (this way it looks like the famous Zlin Z 226) and open cockpit. The plans are available on the Manna Aviation, but the webpages weren't updated for many years, so I have some doubts if it's still valid.

The construction is all wood (therefore cheap), but I wasn't able to find much info about the flying characteristics and owners reviews of the aircraft, that probably because it's a French design, so most info will be in French that I don't speak.

Rutan VariEze

varieze

Well, I'm not really considering VariEze as my next project, but it's so unique aircraft I had to share it here. The shape is very strange, the flight characteristics are a bit different from the conventional airplanes, but look at the performance charts. This plane is fast as hell, can fly over 1000 km on a fuel tank and is very economical. It's also the plane that brought the composite construction techniques to the homebuilders world. The plans for a modified version, the LongEZ can be found on the internet and it's still being build today. Unfortunately, the stall speed is to high for the ultralight to be legal in the Czech Republic.

Sherwood ranger

sherwood ranger

Ok, I really fell in love with this aircraft.It's an open cockpit biplane with a really nice and simple riveted construction and folding wings (check this video, the wing folding mechanism is the best). They sell kits, which is nice, but again, no plans only option and the kit is 15k GBP (without VAT) just for the airframe and controls. That's a pity, building from scratch would be a magnitude cheaper (when talking only about the material).

Kiebitz

This is an airplane I was really seriously considering. The construction is very simple and cheap, it's just bunch of aluminium tubes and tons of rivets (check construction page). There's a live community of the Kiebitz builders and owners. The problem is the MTOW, it's limited to 450 kg as it was designed for German ultralight rules, which doesn't give much room to add any extras to the build if I want to meet the 'two 100kg pilots and fuel for 1 hour of flight' legislation requirement. The author's plane weights around 250 kg and he says the 210 kg should be doable.

The plans are readily available from the Michael Platzer, he doesn't speak english good, but the german emails together with english translation were good enough to realize some other drawbacks of this plane. Michael sent me an agreement with the common clausules (only one plane to be built from the plans, no modifications to construction are required,...), unfortunately he requires to check the plane before putting the fabric on personally, also the first flight must be done by the Michael himself according to the agreement. He would make a German paperwork afterwards. This ruled out this plane from selection, the modification to the wing spars that would increase MTOW is not permitted and by the local laws, the LAA assigned test pilot has to fly the plane first by the local laws. Therefore I would need to haul the plane ~400 km away to German border for Michael to fly it and would get the German papers for the plane.

Murphy Renegade

murphy

Another biplane to the selection, the Murphy Renegade looked very promising, plans only option available, riveted construction. But after closer look and some googling I found out the front cockpit requires some serious gymnastics to get in and the plane doesn't fly that well when flying with two normally sized guys. It's more like a single seater with second seat suited only for your kid or dog... I still really like it, it looks gorgeous, but it's not the one.

Fisher Flying Products

Celebrity

The Fisher Flying Products offer multiple interesting airplanes with both plans and kits options. I've heard some rumors about not so good flying characteristics of the R-80 Tiger Moth replica, but the Celebrity/Super Koala looked promising. I've subscribed to info emails which should result in free plans sample, but the webpage seems to be broken somehow, no plans arrived.

The construction is all wood, which promises a low price of the material and the construction looks interesting, this could be the right way.

Pietenpol Aircamper

Pietenpol

The Pietenpol Aircamper is the most classical homebuild you can find, plans are still available and there are thousands flying with various engines and modifications. The parasol configuration is quite interesting and there are several different options in the plans, like a wooden or metal fuselage, one piece and three pieces wing,... There is also a modified version, the Grega GR1 with metal fuselage and some other updates.

I was seriously considering building this due to the huge community and interesting vintage look, but it's not very STOL capable airplane and it requires a bit more powerful engine than other planes (won't fly with smaller 2T rotaxes,...). Also with the wingspan and non-foldable wings, it would be harder to find suitable place for it on local airfields with crowded hangars.

Kitfox and other foxes

kitfox

Everybody know Kitfoxes, these planes are sturdy, nice looking, have some STOL capabilities, nice wing folding system and there's a lot of clones of the earlier models (Avid Flyer, Eurofox, Raven,...).

Unfortunately the cost of the kit is quite high - around 35k USD per kitfox 7 kit (wasn't able to find out if kits for older variants are still available), the Eurofox only sells finished planes (63k Eur), the Avid has a lower MTOW (speedwing has MTOW of 1050 lb),.. I wasn't able to find plan option for any of the foxes, with the exception of the Raven, but there's not much info about this particular clone and it's welded fuselage anyway, so let's move on...

SkyRanger

skyranger

The SkyRanger is very interesting aircraft from the UK, the fuselage is riveted from the aluminium tubes, very simple construction, folding wings, reasonable performance, nice flying characteristics...

What I don't like is the covering, the fabric is sewn into a pockets that slide over the construction and are tensioned by a rope. This is very clever solution, it's easy to inspect and repair any part of the plane without ripping off the fabric, just loosen the tightening system and pull it off, do the work and put it back. Simple and elegant. The problem is the fabric has a lifetime limited to around 5 years, after this period it has to be replaced and it's not the cheapest one, around 1000 GBP for the covering, that's about the same as the ordinary fabric that is glued to the construction and is airworthy for ~20 years.

They don't sell plans and the kit is quite expensive - 16k GBP. That's quite a lot for a bunch of aluminium tubes, rivets and few extras. But the construction is really nice.

Zenith CH701

CH701

The CH701 is the plane that everyone thinks of when hearing STOL. The plans are available for a reasonable price and the sheet metal riveted construction is not impossible to do at home. The plans even contain drawings for all the rib forms and other pieces needed to make the parts from the raw stock material. The flying characteristics are almost unbelievable, the stall speed is mostly non-existent, just pull the stick up to your stomach and wait, it will slow down to walking speed and start to drop a bit, nothing else. The CH701 design is pretty old, there are updated, bigger versions like CH750, but the construction simplicity is a bit reduced and it's more expensive, also a 100hp+ engine is must for this version, so let's stick with much lighter and smaller CH701.

There's also a wing folding option, but the mechanism requires tilting wings vertically and as the wing tanks are located in the wings (surprise, right?), it's not possible to do it with full tanks, so with exception of long term storage, it doesn't really make sense to use it. And for long-term storage, it's easier to take the wings off.

I've visited a local guy who built the plane from the kit, had some chat about it, looked into the plans and decided this is the plane I want to build. From scratch! So I've ordered plans from the Zenith company, after two days, I've received refund together with email "We don't sell plans to Europe, USA only". And that was is. The kit cost is not much cheaper than older second hand CH701 with automotive conversion engine.

I.C.P Savannah

savannah

The I.C.P. Savannah started as a CH701 clone, there was even a lawsuit about this if I remember correctly, but today, it's a completely different plane which is even more capable. Additionally, the shape is much more rounded and there's no strange cutout in the wing over the cockpit, so the plane looks much better than the CH701, also the stall behavior is better.

The construction is similar to CH701, riveted sheet metal. With it's MTOW at 600 kg, it can haul 50 kg more than the CH701 (the empty weight is almost same). However the cruise speed is much higher and the airplane is much sturdier. It's definitely superior to CH701, but again, only kits and finished planes are offered and the complete kit price is around 30k EUR, it's even more expensive than the CH701.

Ragwing RW19

ragwing

The RagWing RW19 is a very interesting airplane. It looks like a Fiesler Storch, flies like a Fiesler Storch, but it isn't the Fiesler Storch. It's all wood construction with incredible STOL characteristics. There are actually two options, one with tandem seats, one with side-by side, the only difference is the width of the fuselage. And there's a folding wing option similar to original Storch!

With empty weight around 250 kg and MTOW at 550 kg, it provides plenty of room for the crew and payload, the stall speed is supposed to be 32 km/h and it cruises at 75 mph (120 km/h), that's almost 4 times the stall speed! It has a lower wing loading than CH701, so the advertised stall speed seems to be correct, but I have some doubts about the cruise speed.

The plane was designed by a Roger Mann, who is still available to various questions regarding his designs. The plans can be bought for 25 bucks, build videos for 45. That's a bargain, so I've bought the plans immediately. After some time browsing through them, I realized this won't be a best first aircraft to build as the plans have many blind spots and a lot of details must be done by a builder ad-hoc. The basic construction is there - fuselage details, wings (there are two slightly different rib patterns, routed plywood and built from sticks, the shape is not equal by few mm), empennage, wing struts, landing gear. Rest is up to a builder (seats, engine cover, cockpit interior, fuel system...). There's also very little info about the hinges, tail wheel, the wing folding mechanism drawing is a single hand-drawn page. And there's no build manual, just a list of materials and few notes regarding the center of gravity and wing dihedral.

The Roger is not an aircraft designer and he mentions it on his webpages, the RW19 design is heavily inspired by the Mini/HiMax family of planes. Therefore I've browsed the internet, found minimax plans and used them as a reference when I hit something not that well documented in the original plans. Then I bought the build videos, that filled a lot of these blind spots in the plans. There are still some gaps, mostly related to controls in interior, but these can be solved.

I've redrawn the plane into the OnShape online 3D CAD tool (the result can be found here), found an inspector who would supervise the build process and do some basic calculations just to be sure about the design capabilities (I had some doubts on the MTOW after some initial calculations I made), unfortunately he passed away before I actually started building (old man in COVID times...). In the meanwhile, I bought an old HiMax for a small restoration project and found another inspector who would check it's state, I had some chat about the RW19 with him and he discouraged me form building it as he knows the plane and said it wasn't flying really well and the construction is far from perfect. So I went searching for something else.

Bearhawk LSA

bearhawk

The Bearhawk LSA seems like a miracle, it looks like a good old J-3 Cub or maybe a Super Decathon - tandem seats, A-65 or equivalent engine, but here the similarity ends. The Bearhawk is a modern airplane in a retro suit, the cruise speed is around 190 km/h (at 5 gph), it can haul around 270 kg of payload by legislation and it's calculated for MTOW at 680 kg. And while the cruise speed is so high for a high-wing aircraft it has a pretty decent STOL characteristics too. Although it doesn't have any flaps (for simplicity and weight reduction), it can land on a few meters with skilled pilot.

The fuselage is welded from the CrMo tubes and cloth covered, the wing is riveted from the aluminium sheets. It doesn't have a wing-folding option and it requires a significant amount of welding, but the performance is really gorgeous, well beyond all the other planes mentioned here and they offer plans-only option for 300 bucks including shipping, that's just amazing!