flywise

As an AME I was surprised once to find out that on a Cessna C-172 you were NOT allowed to fly without spinner. Indeed the spinner on this aircraft is designed and important for engine cooling...

On another application like a pusher Long-ez, you can have up to 50 Lbs thrust increase in flight (if my memory's good) by installing an aerodynamically shaped spinner.....It was explained to me that the low pressure area around the prop hub can be greatly increased using this long and pointed spinner....

Obviously a tractor aircraft benefits from a clean spinner installation (where as little space is left between cowl and spinner and no "step" present) aerodynamically.....don't know by how much though....

My 1/2 cent

One question I have regarding C of G position is : How to determine / what incidence does the extended leading edge have on C of G position. The original C of G is measured on the spar leading edge....an extended leading edge is going to change that measurement ( also, does it  change the C of L) ? As I see this the aircraft C of G stays where it is for a specific loading (extended LE same as no extension) but the measurement is going to be wrong.......so the pilot could be outside the envelope thinking he is inside !!!!!!!!

Let me know your thoughts..I am a bit unsure about this one. It came up because I compared empty aircraft C of G with another Catalina who has extended LE. and all the measurements are quite off compared to mine.......

P.s Same problem when you do your initial aircraft weighing to find your C of G position

Hey guys, I guess it's about time I introduce myself..I have been working in europe and in the african desert as an AME for 25 years and rated on aircrafts such as the B-737 3/4/500, Saab 2000, ATR42/72, Fokker F-50, DHC-6 Twin otter, Pilatus PC-6 porter, Bae 146 / RJ85 series..I probably have forgotten a few. Anyhow I moved to Canada from Switzerland 8 years ago. In Switzerland, I finished an experimental Rutan Long ez and flew it a 100Hrs. Also had this french built wooden 1959 Wassmer WA-40 for a few years.

The idea of moving to Canada came because of my dream of flying floatplanes, ...hence the avid catalina I have brought back into the air (my wallet shrunk from the crazy idea of owning a Beaver to buying an avid I could just afford ....)

As a job I do aerial photography using drones but also the Cat....making no money but having a blast...

Cheeeeers

Hey Fred, I do agree it's expensive....where did you find cheap ones working in fuel? Back when i searched I didn't find any specifically built to withstand permanent immersion in fuel..

Hey Fred, the sensor and indicator/test switch is from these guys    http://www.pillarpointelectronics.com/sensors.html

Very easy to install, no moving part....it can also be fitted inline of a supply line instead of the tank....

you can see it on the left , left of the trim switch

Same here,

I have a header tank with a closed vent. This vent is only opened when /if I empty fuel from that header tank so as to refill it...I also aded a infra red low fuel warning system on my header tank which will also tell me if there is any air in it.....

P.s I only have one main tank going into my header

My 2 cents

The one thing I would be wondering when using gorilla glue is aging...How good is it a few years down the road. We know that with T88 but not with Gorilla.

My 2 cents

I guess now you'll have to install HUGE tires to get the deck angle right....or lengthen the main gear....or lower the tail gear. So many choices   what will you modify?

I would for sure file it down to have the 30deg if you can't get the correct elevator up travel by adjusting the rod ends.

Cheeeers..

P.s on the Catalina, the elevator stop is not riveted but rather installed  moveable to allow adjustments.

You must give us some details......

Good info guys, thanks 

I am sure it's great but my concern would be a crack in the exhaust. As I understand this, if it's ceramic coated there is no way you can weld a crack in your exhaust. Also a crack under the coating could go unnoticed....Had a crack in my exhaust, was easy fix as I don't have this ceramic coating.

My 2 cents.

Well done, that looks neat

Hey EDMO, for starters this is a not a birth certificate but instead it is a ....death certificate from 1839!!! I am having a little trouble reading some of the handwriting...I will have another good look tomorrow morning ... brain works better then it seems.

I speak German and might be able to shed some light. 

Hey, I found a crack in my engine mount......engine shipped yesterday

When we're talking overspeed, I mean something serious like I did at 7400Rpm (~130%). Also a note regarding the interference fit engines, if you go high enough in Rpm, then even a non interference fit type engine will experience valves hitting the piston crowns...it has to do with the excessive velocity of the pistons and the valve springs not able to keep up. Basically the valves are not shut when they should be. This is why on racing engines, one of the first items being modified are the springs to get a faster "shut" speed.

Hope that makes sense

Hey Dusty.

....this is the million dollar question. Before I decided to tear things apart I spent numerous hours on the net trying to find SOMEONE.. who's had an overspeed. Well I found NOBODY talking about it!!!!  I can only guess that some have had it and don't care, others might have had it and don't know the rpm reached (some early gauges only go up to 6000Rpm) not mentioning the difficult task reading a gauge precisely when sh...t happens. Last the rotax dealer stands on the cautious side when you ask him. They won't say what damage they found at what Rpm...basically if it's over 6500Rpm they say it definitely needs teardown inspection...

The other thing to consider is that 2 engines are never the same. My engine only has 127Hrs...maybe a higher time engine would have different results.

I am writing about my experience to help others in the same situation.

524Lbs....

SCAM>>>>>>>>>>>May be actually legit....I would start by asking the serial numbers of the engine. You can check on this list if it's a stolen one.

https://legacy.rotaxowner.com/si_tb_info/serviceletter/sl-912-013-r11.pdf

Yes got you now.....and that is the route I am taking 

P.s to anyone searching for a good used rotax 912 uls at a reasonable price......be aware, I have looked at 3 engines for sale ..... but in the end, all 3 actually did not belong to the person trying to sell them, just crooks wanting to make easy money

Yes it is very tempting to do the overhaul myself.....but at this time my garage/shop is a mess (no heating, no insulation no electric power except a 300ft extension)...not ready to tacle a clean job. Also I believe there are quite a few special tools and products needed for the 912 engine besides the parts I'll have to buy at a premium price.

The solution I found (Jason at http://badasspowersports.com ) I hope is good as he has been working on the 912 rotax as the distributor for edgeperformance (  http://webshop.edgeperformance.no/index.php  ) here in Canada for some years now. They actually take brand new 100Hp 912's and turn them into 170Hp turbo monsters.......

My big advantage is that he has a stock of reasonably priced new 912ULS cylinders, pistons and even reduction gears  he can fit to my 80 Hp block. Also he has lower prices for all other rotax parts. Last and not least he will set up and adjust fuel injection and a high performance cam he sells....

To start with, for the dismantling, overspeed inspection of the engine it's about 750 bucks....I find reasonable.

I will keep you guys updated....I am really eager to know if my engine has damage....

As it stands now, I have two options...buy a new 912 ULS engine at the canadian dealer (very expensive and they would only give me peanuts for my engine) or go to http://badasspowersports.com and they would go over my engine, install new cylinders (100Hp bore) pistons, a high performance camshaft and a fuel injection, and gear the engine from 2.27 to 2.47. giving me better than 100 HP, lighter weight (-8Lbs) and a thoroughly checked through engine..

Problem with all the official rotax dealers, they refuse to install or warrant the high compression Xtra pistons. So if I have my engine gone through them it would come out as a 80Hp 912 and nothing else......

Cheeers

Hey Guys...a sad week end just passed. You probably already know that I was struggling with my previous GSC/warp drive prop. Indeed when I applied full power for t/off I usually set the pitch at about 5300 (that's before the plane is moving) and this way I got 5700rpm at climb out, later to be set at about 5500. Unfortunately my prop was feeding back too much force into / through the linkage and bending a bracket doing so. The result was that just when taking off, the prop went into a finer pitch and made the engine go beyond 5800Rpm. At first I did not realize what was happening as at each take off I had to dial in a bit more/coarser pitch....Once I had a real bad overspeed going well beyond what Rotax accepts. Of course I reduced power as quick as i could and as I was already flying I kept going and landed safely at my home lake. When I read out my Rpm gauge History my heart sunk....7400Rpm

Now officially this means the engine is toast even if it only lasted a couple of seconds. As I fly over lakes all the time, mostly alone I took the decision at first to do the overspeed inspection (compression, filter, borescoped the cylinders etc) and see if the engine keeps me going. There was no sign of anything wrong for about 7 Hrs (besides a little voice in my head) but on my last two flights....not so good. The engine was much harder to start and was running a bit rough (these are some signs of overspeed damage)

To cut the story short, I have removed my engine (912 UL) and I will replace it wit a overhauled 912 ULS. Here the reasons....some obvious 

1.Engine experienced overspeed

2.Don't know if previous owner has had issues / overs speeds (probably yes)

3.Engine was fitted with the Xtra kit boosting compression ratio....Rotax issued a service bulletin totally against that mod (maybe too much pressure on the 2 piece crank?)

4.I fly in very remote areas and if I have an engine out it will be VERY costy to get the aircraft back home.

5.I might damage the Cat doing an engine out landing....costing in the end more than an overhauled engine

6.Overhauled engine will have all SB. and mods done (by rotax distributor ROTECH)

7. Last and not least ...get rid of that little voice in my mind....do it right

Here some pictures of my ordeal....actually the Cat looks real good without engine....