Bending the rudder skin

Bended the rudder skin and started mounting the rudder jig. There is a lot of trimming to do on the rudder, and I need to mark all that before assembling (I'm not entirely sure if it is best to cut everything before riveting). Ordered "RTV 3145" from Aircraftspruce, probably the most expensive glue ever, 33 US$ + shipping for 4 oz (118 ml), a Christmas gift all by itself, he he. This is needed at inside the trailing edge of the rudder to prevent cracking.

Rudder skeleton riveted

Riveted together the rudder skeleton. At first it seems like the rudder is fastened to the rod end bearings with only two rivets each, so that only six 2/16 rivets are holding the whole rudder. But when looking just a bit more closely, the rod ends are really holding the rudder with the bearings and the rod end nut squizing the plates and spar together. The six rivets are only there to keep the jam nut positioned. Nice design.

The jam nuts on the rudder seemed to be bare steel, so I primed them using the zinc chromate rattle can.

What were they thinking?

On November 20, 2008, the Norwegian government decided to purchase about 50 JSF, or F-35 to replace the aging F-16s. This was after several years of analysis. In the beginning the contenders were Rafale, Eurofighter Typhoon, JSF F-35 and JAS Gripen NG. During the last year the only two left was JAS and JSF, and the media have been full of discussions about this. Then suddenly, one month earlier than expected they announced the decision of going with the JSF F-35.

This was a strange day. Norway has never had any airplane production, although there are several companies producing aviation parts and pieces for export. Nevertheless, the only real airplane production done here is under the ambrella of EAA Norway, making me a part of the Norwegian aviation "industry" more than the industry itself, he he. Norway has always purchased fighter aircrafts, mostly form the US. We have allways had cool fighters, real fighters, like the Spitfire, Mosquito, Vampire, F-86, F-104 (at least very fast and cool), F-16. And now this? the F-35, an airplane that looks like a bath tub!

The F-35 is stealthy, it has super avionics (so they say), and I am sure this has lots of tactical advantages in the "beyond visual range" area that I know nothing about. But in the near future, when most fighters are stealthy to a higher or lower degree, there will be no "beyond visual range", so the fighters will need to be agile. Technology for detecting stealthy aircrafts already exist, at least as prototypes, but I guess stealth is an advantage that cannot simply be disregarded. Anyway, since the whole stealth thing is so fuzzy and unclear, I wanted to look at good old physical relationships that tells the essentials about the flying abilities. I headed to Wikipedia and found data to set up some characteristics of the F-35 and compared it with other modern fighters.

First is the weight, just to get the size of the plane. The F-35 is more or less of the same size as the F-18 E Superhornet.

Then the thrust/weight ratio loaded (I guess "loaded" in Wikipedia means with fuel and basic ammo or something similar, it is not MTOW), and the same thing with afterburner. This gives some clues how it will climb, turn and accelerate. The F-35 is worst, but comparable to the F-18 E.

Then the wing loading. This shows the effectiveness in turning and maneuvering in general without loosing speed and burning fuel. The F-35 is worst, but still comparable to the F-18 E.

With the worst T/W and highest wing loading, at least it must have some speed, but no - it is by far the slowest of them all. The only good thing about the F-35 is stealth, otherwise it is underpowered, heavy and slow. The best description is probably an anaemic but stealthy F-18 E.

Real fighters are the Eurofighter Typhoon, the F-15 and the Gripen NG. The F-22 is also similar, it is stealthy but huge, with almost the same empty weight as the 80 passenger airliner Fokker-70. Typical characteristics for all these airplanes are low wing loading, high T/W and high speed. The Gripen NG is not entirely a "mini" Typhoon regarding T/W, but with smaller wing loading and its smaller size it will be much more agile.

Saab offered a much better industrial cooperation, that would in fact lift Norway several levels in the Aviation department, making Gripen NG something that looks closer to a joint Norwegian/Swedish development and production. But - when the decision is made exclusively by politicians and tactical US-centric military personell, I guess the engineering dimension being self sufficient of military technology is not understood - at all. The Vikings made their own longships, light - maneuverable and fast, that's what made them invincible. The Gripen NG (and Swedish fighter technology in general) is a modern continuation of this vikingship building tradition, and Saab and the Swedish government invited Norway to be a part of it, but the Norwegian government said no. This is one of those things I will never understand, no matter what the F-35 turns out to be.

Gripen NG would be perfect for Norway, but the Norwegian government said no (to all of it) and instead chose to purchase something that looks like the least maneuverable, the heaviest and slowest fighter-design in the last 30-40 years.

But what do I know? I am only a slightly preoccupied person trying to build my RV-4 :-)

Primed the rudder skeleton

Primed the rudder skeleton parts with the P05 Strontium Chromate Epoxy. The aluminum plate from Sweden arrived within a couple of days last week.

Finished rudder spar

Deburr and priming next, I think.

Rudder spar assembly

Fixed the rudder spar lower assambly. Lots of drilling through lots of pieces. Two holes left in the R405 + the top spar before deburr/prime.

The aluminium was sent from Sweden. Certainly much cheaper than sending from the US, I wonder how long it takes.

Ordered aluminium and fixed some lights

Fixed better ligthing in the shop. Ordered aluminium from Sweden, Arigo Flygmateriel, thanks to Bjørnar Volstad. This is much closer than Oregon :-) and they have plates, L, pipes and so on amongst lots of other things.

Hinge support plates

Drilled the hiinge support plates.

Adjusting rudder hinges

Drilled holes in the rudder spar and started adjusting the holes for the hinge bolts.

R-405

Fabricated the R-405. Piece by piece ...

Fabricated new R-406

Had a 6 by 12 inch 0.063 plate for the wing or fuselage (don't remember exactly what it is going to be used for). Fabricated a new R-406 from that piece. Have to order more 0.063 later, but I will check for some (more) local supplyer of aircraft aluminum. It just doesn't seem right to order every little piece from the other side of the globe.

Dimpling the VS

Let the primer cure over the night and dimpled all the holes in the VS skin and skeleton. Tried it in the jig, just to see if everything fit. I have to wait for the controller person to sign it off before closing the structure with rivets.

Started on the rudder main spar and the reinforcement plates. The reinforcement plates are pre-made from Van's. When trying to position them, something was wrong with the R-406. The main hole was offset 3/16 compared to the hinges, so the whole plate would be pushed 3/16 down. This would make the rivet holes on the edge of the spar, and a bit outside. I thought I had measured wrong, but when looking at the R-406 and compared it with the drawings, I saw that the R-406 was made wrong. The hole for the hinge is 3/16 further up than it is supposed to be. I think I will make a new R-406 myself from another sheet with the same thickness and get Van's to send me a new sheet, so I don't have to wait for shipping.

Fixing up the VS skin

Finished trimming, deburred the skin and skeleton and primed the VS skin.

Trimming etc

Trimmed the trailing edge of the vs skin and removed strips of blue plastic around the holes. Deburring next.

Trimmed the tip of VS

Used cutters and vixen file to trim the VS tip (0.5 inch from the rib). Tried the fiberglass tip, and it fitted almost perfect.

The wires arrived last friday.

Finished drilling the VS skin

Finished drilling the skin. When I took the skin off again, everything looked OK, no holes in the wrong place. Need to drill the two fore-most holes at the tip, but I have to take the skeleton off the jig first.

Drilling the VS skin

Finished marking on the jig and the ruler. Transfered the markings to the skin and started drilling.

Markings for drilling

Continued marking lines and holes and flutings for the drilling process. Drilling holes in the skin is next.

Visit to Praha, Czech Republic

In June we (Olaug and I) visited Praha, or Prague, in the Czech Republic. One morning we went to Kbely Aviation museum just outside the city center. It is a very interresting museum with lots of very rare aircrafts (several one offs in the entire world), but it is also very crowded with aircrafts, making it difficult to take pictures.

I have includes a few pictures here. One geared radial Walter Mira II-R (95 HP). A few very nice light aircrafts from Zlin. The only two seat Me-109 in the world today (Me 109G-14). An Me-262. One La-7, probably the best Russian WWII fighter. One Yak-17 (the resemblence to the Focke-Wulf Ta-183 and Me P1101 prototypes is rather striking).

Further adjustments and trimming of skin

Adjusted the jig/skeleton more precise. Added another fastener to hold the fwd rib. Trimmed the skin further. I think I have cut of 5 or 6 slices on the tip now to make the overhang not too large.

Started marking the rivet lines for drilling holes. This is actually a bit time consuming, and requires attention, since it is not possible to see where to drill when the skin is on. I have to rely on markings on the jig and the ruler.

The VS skin seems to be cut and bended much more precise than the HS ones. All that is needed of trimming here is to cut off material at the tip. And Vans told me they were not able to cut/bend the HS skin with more precision than they did? Somehow I find this a bit strange, but who am I to tell?

It is good to be building again. To see that all the pieces starts to form larger components of a plane that I am going to fly sometime in the future, is a strange feeling sometimes.

Adjusting the skin on the VS

Riveted together the VS skeleton. Postioned the skeleton in the jig and and started to adjust the skin

Primed the VS skeleton

Jig changed

Changed the jig for skinning the VS. Repositioned hinges and temporary vertical member. Need to prime the skeleton and rivet together before skinning. Wires are in the mail.

Changing the jig, ordered wires

Started changing the jig for skinning the VS. I ordered the standard wiring kit, the only one avaiilable for the -4.

Wires

Have to order wires for the lighting (needed before skinning of the VS). I will go with the standard Van's wires kit. I want simplicity, so I will probably go with LED for marking, but LEDs are very expensive compared with ordinary flash. Light power (candela??) per dollar for LED must be way down compared with flash, but simplicity and weight also adds in here... Landing/Taxi lights is also something I want, but I'm not sure I really need it. That decision has to wait.

I have had a break in the building process, but I am by no means giving up. The reason for the break is a new job, fixing up my software in the evenings (a simulation program, more or less in relation to the new job) + some more personal happenings. Altogether the available spare time and the mental surplus capacity has just been too low to think about building. But - things are looking better.

VS Skeleton ready for deburring/priming

After measuring and measuring again and ... the skeleton is ready for deburring and priming. The main spar must be installed in the jig.

Found another error in the manual/drawings, or at least something that is very easy to misinterpret and get wrong. In the drawings, the angles for the ribs are measured from the main spar. The hinge line on the VS is NOT parallel to the main spar, so when installed in the jig, repositioning the temporary hinges from the HS (as per the manual), the 5/8 inch offset of the HS-406 tip measured with a "water bulb thing" (as per fig 6.12 in the manual), cannot be correct. It has to be MORE than 5/8 to compensate for the offset hinge line, or the 93 degree angle will only be 90-91 degree. It looks like this has caused some confusion earlier, because the manual states that the drawings have been checked and rechecked and ARE correct. So this means that the manual is wrong. At least it mentions nowhere the importance of installing the spar in the jig so it is absolutely horizontal, or to compensate for the unparallel hinge line when using the hinges with no shimming on the jig.

Skeleton on the VS

Continuing with the skeleton on the VS. Lots of measuring and odd angles. Have to order some wires for lights. I think I will use LED instead of bulbs.

The HS is finished

The first piece of the RV-4 is finished.

More riveting on the HS

Got my pneumatic rivet squizer from Averytools along with rivets and a rivet cutter from Aircraft Tools Supply. Used the rivet squizer on the trailing edge. From all the tools I have purchased, the pneumatic rivet squizer must be the top.

The riveting is going very well. On the next parts I have to remember not to drill holes too close to the ribs.

Started riveting the skins

After a few tries with wrong bars, the first line of rivets on the HS is formed. According to Tom at Van's it is best to try to rivet as much as possible in the jig to be sure that the HS is straight.

Dimpling the HS

Dimpled all the holes in the HS. Riveted on the extensions to the HS-406. Primed the skeleton "a bit" with epoxy on top of the wash primer.

Visit by the controller

The controller visited today, before I rivet on the skins. After a few adjustments to some rivets that were not squized enough, everything was OK. I think I will order a pneaumatic squizer from Avery tomorrow, or at least before I start with the wing spar.

Primed the HS skins

Primed the HS skins and touched up some on the VS spar.

Trimmed and deburred the HS skins

Trimmed the LE and tip of the hs skins. Deburred all holes. The HS is finally ready for priming and riveting.

Fixing the HS-406

Adjusted the fabricated tips slightly and drilled them on. This clearly shows the original HS-406 being about 1/2 inch too short. The only thing missing now is that the dimension on the drawing is wrong and should be 10 1/2 inch instead of 11....

These tips probably will not do much structurally, but they certainly holds the tip of the HS better in place. When primed and riveted on, the whole thing looks better as well.