Windshield

Hey everybody,
First post this month - just in time actually. The reason is very simple. NO WORK had been done on the Aero. November and December were fully booked and no resources were left to work on this aircraft. A pricing policy change and some new help will get the project rolling a bit more rapidly in the first quarter of 2012.
Still, some stuff was outsourced - like the windshield.
The story goes that the bubble windshield was the first blown windshield produced locally. Was not all that great to start with. The unfortunate S5-MBB had a crystal clear windshield, but was not optically correct due to waviness in the plexiglass. When flying it, one had to constatlly weave around with the viewpoint to get the ''correct'' sight. The other problem was that our windscreen was full of microcrakcs as evident in this image. These are internal cracks that cannot be polished out, so the whole windscreen was unservicable.

Very, very big image, to show the cracks clearly

So this is the correct solution for the problem:

Looks nice, doesn't it? We will see how it is installed.

Thanks for stoping by. I wish all of you to stay healty in 2012! Happy new year.

A short introduction to Aero-3

Our workshop has a new roof. Now we have to tidy up a milion small details and this will take some time. So nothing new to report on the Aero, but I was thinking that this might be a good time to explain what exactly is an Utva Aero-3.

Utva Aero-3 in flight.

Utva Aero-3 is a primary trainer that was built in 1959 in Yugoslavia. As you might had noticed in the previous posts it is made of wood, but is powered by a Lycoming O-435 engine, which was pretty standard for that age.

This trainer was built primarily to serve in the Yugoslav Air Force Academy during the sixties, when the country was receiving a huge number of aircraft through the MDAP scheme. This needed a steady influx of novice pilots. Therefore the Academy devised a three year training programme. First years was basic training on the Aero-3, second year advanced flying on Soko 522 (picture is an older post), and third year operational training.

Most Aero-3 trainers wore trainer yellow paint scheme, but these two are camuflaged.

Now as I've written in a lot of previous posts, the aircraft is just a vehicle for people to communicate. Now, let us talk more about the people that flew Aeros.
This picture is from the personal archive of Mirko Anžel of Trbovlje. It was taken in 1965 during his training in the academy. Since he was the number one of his class, he opted for fast jets and therefore flew 10 hours of TV-2 (version of Lockheed T-33) and then solo on the F-86 Sabre.

Mirko Anžel before flying the TV-2.

Mirko always recals that this was amazing. His generation had almost no time on Soko 522, since they had a fleet problem of cracked propellors at that time. Therefore they flew about 120 hours on the Aero-3, a few hours on the Soko 522, 10 hours on the TV-2 and then soloed the Sabre.

Mirko Anžel, left. Notice that the Sabre is one formerly used by the 204.lap aerobatic team.

This image shows him in front on the F-86, with his instructor in the center. Mirko then went on to MiG-21s and graduated from EPNER at Istres, France as a full course graduate. Even now, he recalls that his greatest profesional achievment is the Sabre solo. Everything that came later, like the MiG-21, Mirage III or the Caravelle, was not that much of a jump then it was from the Aero-3 to the cockpit of the Sabre. Mirko is a constant source of knowledge and advice. If we were not restoring the Aero, we would not had met him.

Vojko Gantar in front of Lockheed TV-2, right.

The image above shows a very young Vojko Gantar from Idrija. Vojko was one of the top Yugoslavian Air Force fighter pilots. At age 23 he was assistant squadron CO on Sabre D fighters and then spent 22 years flying the supersonic MiG-21. He went through the same process Aero-3-Soko 522-TV-2-Sabre during his academy years. His last years before the breakup of Yugoslavia was in command of the MiG-21 training squadron at Pula, now Croatia. Again Vojko is one of the very best teachers and menthors you can imagine.
Perfectionist by nature, open minded and extremly willing to help out, I think he might be one of the most valuable forgoten pilots that we have right now.

So again, the aircraft does not matter. Sure, it is a nice aircraft that can teach tailwheel, basic aerobatics and actually has some post-stall flying characteristics (which is totally untrue for aircraft built under JAR/FAR-23, which just do not stall...), and with a supported Lycoming engine to boot, but it is the people that matter. What matters is that Vojko totally secluded from flying, worked as a mountain sheppard, but now he is back again lecturing on hand flown IFR and supersonic flying.

This is why we restore aircraft.

Till next time. Have fun, go beyond your ego, seek advice, talk to people, respect your elders.

Fairings fitted

This week we spent some time fitting the fairings to the center section. The fuselage had original holes, but the center section needed new ones drilled and nutplates installed. This is the end result.

The fairings are actually the whole D-box (leading edge), walking surface and wing-to-fuselage fairing.

Up close.

And the other side, but looking from the rear.

This is probably the last post for a while, since we have a bit of a backlog on orders and in between we are changing the roof of the workshop. Which is a bit stressfull in november with a shop full of vintage aircraft and engines.
Next up is dry ice blasting of the fairings and some other metal parts and fabric covering of the center secion. Have fun!

New trim

I forgot that we also built a new elevator trim surface. It started out as usual - the original part looked worn, but acceptable.

Original trim surface after paint stipping.

So at this time, I made a template for locating the holes for the trim control cables. This template was then used after the new fabric was installed to mark out and cut the position, where the cables penetrate the fabric.

But then I blasted the part and the aluminum surface literary came apart as evident below.

Notice the small holes bored open by the blasting media? I didn't even bother to continue blasting, since this part is gone.

Therefore a template was made, new alluminum cover was hammered over and much to our surprise the trimer even had a wooden core. Janez fabricated a new one.

New (bottom two) versus old. Notice how the original core shrinked in one direction due to moisture.

Not being that skilled in working with aluminum those curved, wedge edges were not that easy to get right.

Then everything was fitted to the elevator to verify aligment. Notice how the elevator is already covered.

Then some rivets and we are done! Notice the fixed trim tab for the rudder above.

If you like this aluminium thingy and would need an inspiration, please check out the story of Arnold Ebneter and his E-1. This link should get you started.

The missing time

I think that I had already mentioned we were a bit stuck on the center section and were awaiting plans. At that time work did not halt on the project, but continued on the tail group. So this again is an overview post of work completed in the past. With this post I think I had covered more or less everything completed on the aircraft to date.

The leading edge plywood on the horizontal stabilizer was showing rot and moisture, so we opened it up.

Torsion box of the stabilizor opened and rudder in the background. Does not look bad at all. At this point.

While half of the stabilizor was in excellent condition, the other half again showed signs of water present.

The left side was just destroyed. You can see the moisture and rot of the plywood.

Therefore the usual course was followed - just keep taking parts off, till we reach sound structure.

This is looking at the inside of the spar. Notice how accuratly the varnish is applied to the plywood.

 

This meant removing all the halfribs and the front plywood web of the spar.

Notice also the fact that the spar was repaired at least once. So this stabilator most probably took a birdstrike in the past.

So this was the state of the stabilator at the time we reached undamaged parts.

Next up was fabricating new parts to get everything back together.

Firs the web of the spar was added and new halfribs installed.

Then new skins were fabricated.

And scarfed in.

Not to bore you with details, this is the end product, and you can clearly see which are new skins.

Fortunatly the other tail surfaces had only minor damage compared to the horizontal stabilizor. Therefore the elevator was very quickly done.

We repaired only the nose section of the elevator.

The vertical stabilizor had even less work. Only some dents to take scraf patch in.

The following images show some of the fabric covering of the tail surfaces.

Covering the balance horn of the elevator.

Half of it covered.

Some intricate overlaps going on there.

Rib stiching the elevator is complete.

A detail from the horizontal stabilizer.

This is the rib stitching of the rudder. The stiches are only 3 cm apart - per original specifications.

And then everything dissapears under the covering tape - that is why it is called covering tape actually.

Great. Ready for fill coats of varnish.

Thanks for looking!

The most important question this september

Yesterday was a big day. We have mated the center section  to the fuselage. Not really finally, but only to fit the fairings to the newly built center section. But still after such an amount of work dispensed on the center section, it was nice to see it where it belongs.

 Looking inside the cockpit. Can't wait to start installing systems!

And september is still not that far away. So this might be a good time to answer the most important question – WHY are we doing this? WHY are we spending such an effort to restore a 1959 basic trainer.

Well, the first thing to consider is that this aircraft is just a ton of wood, metal and fabric. The aircraft itself does not matter. It really does not matter.

Slovenian aviation history is complex. Since 1909 when Rusjan brothers from Gorica flew their first powered flight Slovenian aviators flew under four different flags (Austro Hungarian, Kingdom of Yugoslavia, Socialist Yugoslavia and independent Slovenia). The complex political climate in these four countries had one leading characteristics - the eradication of achievments of the previous generation.

Today this is still a trend in Slovenian aviation, and unfortunatly this means relearning and repeating the same mistakes all over and over again. This also results in very low national identity and pride. Looking back at this paragraph, I see that this is true not only for aviation, but for all spheres of life.

Therefore this aircraft is only a medium, or a tool for looking back, retriving knowledge, reclaiming identity, building pride and looking forward into the future, with a firm foundation, who we are and where we come from. This aircraft is a ton of pride and selfconfidence.

During the restoration of the Aero-3 we had met wonderful people. Mirko Anžel, Vojko Gantar, Janko Medved, Viktor Hauptman and more. Each one of them imparted knowledge and imparted pride. And moreover seeing such an effort expanded to restore a vintage aircraft made them realise that their achievments were not in vain, even though they were under a different flag. This aircraft is a Battle of Brittain flight – but, we actually need it even more then the British, because Slovenian generations require a medium for transfer of knowledge, experience and identity. Otherwise we will keep loosing money, time and pilots. Like in september.

This image was taken in 2009. I was then a very junior FI. Viktor Hautpman instructed in primary training on the Aero-3 in the sixties. This is how we spent literary hundred of hours.

Viktor died a month ago. This is why we restore aircraft.

The following lines are a description of the life of Viktor Hauptman for Slovenian readers.

Viktor Hauptman je bil rojen v delavski družini v Trbovljah. Ko je zaključil kovinarsko šolo in pričel vajeništvo se je včlanil v Aeroklub Trbovlje. Preko Aerokluba je odšel v Vršac na osnovni tečaj jadralnega letalstva, kjer je najraje letel na jadralnem letalu Čavka. V sestav oboroženih sil je vstopil preko 3. generacije podčastnikov letalstva.  Njegova prva borbena enota je bila 113. lovski polk na letališču Skopski Petrovac, kjer je služboval na domačem lovcu S-49C.

Že kmalu po nastopu službe je začel opravljati tudi naloge učitelja letenja, na dvosedem  UJak-9. Po došolanju za čin častnika je Viktor večino svoje kariere preživel v 105. šolskem polku v Zadru. Tam je z drugimi kolegi iz 3., 4. in 5. podoficirske generacije preobrazil šolanje v Jugoslovanskem vojnem letalstvu iz sovjetskega sistema na mešanico zahodnih sistemov, najbolj podobenu sistemu RAF. Najbolje je Viktor ta prehod opisal s svojimi besedami: ''Ko so šolali našo generacijo je bilo v posebno zadovoljstvo inštruktorja, če je uspel pripraviti svojega učenca, da je na svojem prvem poletu pošteno bruhal. Ko pa smo spremenili sistem dela, je bila pa naša naloga, da na prvem poletu učencem pokažemo, kako se to nežno dela, kako se vodi letalo in s tem smo vzpodbujali kandidate, da so letenje vzljubili in bili tako še bolj motivirani za vse nadaljne napore, ki so jih čakali med šolanjem''.

Viktor je bil eden izmed učiteljev letenja, ki so akademijo Jugoslovanskega vojaškega letalstva zapisali z veliko začetnico. Vojna Vazduhoplovna Akademija.

Viktor Hauptman (sredina) s svojimi pitomci pred letalom Soko 522. Avgust 1966.

 Viktor je v vlogi učitelja letenja služboval na letalih Aero-2, Utva 213, Aero-3, Soko 522 in Soko G-2 Galeb. Na zadnjem letalu je, kot tudi drugi številni Slovenci v 105. polku, profesionalno izstopil iz pilotskega povprečja. Bil je v prvem sestavu demonstracijske skupine Jugoslovanskega vojaškega letalstva na domačih šolskih letalih Galeb. Ta skupina je bila osnova za kasneje bolj poznane Leteče zvezde. (Dokumentarni film - Leteče zvezde, 1987).

Viktor Hauptman na delovnem mestu - zadnja kabina Galeba G-2

V tej skupini je Viktor letel zadnji položaj v rombu, z tovariši, soinštruktorji v Akademiji (Glišičem, Nižičem, Radišičem in Šemrlom – Slovencem iz Idrije).  V tem obdobju je bil solo demonstracijski pilot na Galebu odlični akrobat, enako učitelj letenja v 105. polku Janko Medved.

Akro skupina VVA pred nastopom v Kragujevcu 19.10.1969.  Viktor Hauptman je skrajno desno.

Viktor Hauptman je preživel eno leto na Višji vojni Akademiji v Beogradu, nakar se je vrnil v Akademijo, kot namestnik poveljnika štaba. Leta 1975 se je zaradi pešanja vida upokojil.

Viktor Hauptman je bil letalec z strastjo, predvsem pa izjemno intiligentna, častna in ljubeča oseba. Vsem, ki smo ga imeli srečo poznati je pustil globok pečat in predvsem svetel zgled, ki ga bo težko doseči. Najboljši epitaf za Viktorja Hauptmana so napisali njegovi kandidati iz generacije 1966, ki so mu na zadnjo stran, sedaj že 45 let stare, spominske fotografije zapisali:

''Mnogo vam hvala za sve što ste učinili za nas. To je učinilo da Vas poštujemo i volimo kao nastavnika, čovjeka i pilota.''

Viktor Hautpman je po daljši bolezni preminil v septembru 2011.

A big piece of wood

September was not a good month. Two people died. Not in our company, but in aviation world of Slovenia. The first crashed what was the only curently flyable Aero-3 and the other one was a flight instructor, who instructed on the Aero-3 for a long time. The first death saddens me in the profesional sense, since it seems to me that every accident that happens in Slovenia is just useless, no lessons learned, none gained. But the second one saddened me much more, since a wonderful person, menthor, instructor and teacher left us and I miss him a lot already. More about this at some later date.

BUT, we have a big piece of wood to showcase. No words this time, just enjoy.