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My Jabiru


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Hi all, just joining this group.

I started building my SP 500 in 2005 and 18 months later it became 19-4690.

2.2 gen1. Empty weight of 276.5kg

This was probably the last Sp500 that was sold. It has the largest fin and the factory stopped supplying them to the market and shortly after started marketing the J120.

The engine was the 15th to last gen1 before they released the gen2.

I am very happy with this engine BUT I am seriously thinking of weaponising the pane with a gen4 3.3 as I fly by myself, so a lower pax/fuel load won't worry my......yet.

As I am the builder I think I can increase the mtow a little as it stalls at 43kts. Just depends on the spindly u/c legs!

Ken

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Ello Ken, welcome to the group

I have a 2.2 gen 2 in an Easy Raider taildragger Microlight, was just getting into the groove with it after 7 years with a 912 powered Skyranger then the world went to shit.

Spending the down time researching and planning.

Depending on the length of the shutdown I might remove my engine and do give it a going through including replacing flywheel bolts

 

Hoping the future brings better days

 

Stay safe matey

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I lost my previous reply to this forum, so here goes again.

I have a 2.2 Jab which runs well. The only problem ever was detonation, caused by my using mogas instead of avgas.

At 226 hours I had a misfire when doing a mag check, tried several things to cure it, even swapped over mag coils, but it was the same side misfiring. Engine ran well at low rpm and also at full power

I had about 30 miles to fly to my home base, so I took off and climbed as high as airspace allowed, then set off for home, several landing options available on the way.

At home I removed No3 cylinder, which was slightly oily and found the piston, ring op lands broken into several segments. Typical detonation problem.

New piston, new rings all round, bores honed and it has sine doubled the hours with no real problems.

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I have a 2200 in my CH701. If anything it runs slightly cool on CHT and EGT whilst Oil sits around 90 except for an extended climb when I have only once seen it over 100. I am curious that the manual says it can go to 118 max but doesn’t say for how long that is permissible, so I never let it get anywhere close to that.

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Ken, I don't think you can just increase the MTOW by yourself. My MTOW is 430 kg, with an empty weight of 235kg. For years, I flew with an amended placard with MTOW of 480. I did this after an identical plane ( well one with a heavier empty weight, but the same model exactly ) got a letter allowing him to do this raising.

I had a copy of the letter ( from RAAus) and re-placarded my plane accordingly.

480 kg allows full fuel and a heavy passenger and luggage. 430 does not.

Anyway, one day I had to send a copy of the placard to RAAus and they said this was not legal and I had to return to the 430kg placard.

I wrote to Jabiru and got no reply. I mentioned it to the level 4 guy at Gawler and he said how he had recently got an increase for somebody with a Jabiru. I have so far not followed up on this, as I rarely fly with a passenger and when I do, I do not generally have full fuel. This is really because I like the way the plane performs when it is lighter, not because of the foolish regulation.

The 430 kg was to obey a now obsolete stall speed requirement. It was never a structural limitation.

Gosh your plane sure will go if you put a 3.3 into it. I just hope you don't have a c of g problem as I hate the idea of lead in the tail.

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19 reg you can alter MTOW - owner can modify under Marap if necessary

BUT unlikely to be accepted without support from manufacturer of kit

With J2/400 this is fairly simple (rated to 700kg anyway) - just slow down its stall,

Others like SP Im not sure but recall it being tried without success as Jabiru couldn't/ wouldn't support it

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Bruce, it is my understanding that as I am the builder I must take responsibility with the build, CofG/WB, and stall speed. And these are what I supplied to RAAus before I flew it, they accepted my build, CofG and supplied me with 470kg? So rang them and said that all testing was done at 500kg and so they changed it to that amount. So if I test to say 520 and still meet the stall I should be able to do it I recon.

Graham R. Did some calculations for me and I will have to put 8kg in the tail, yikes! So it will need the battery moved back to the rear curtain area to reduce this number. My main problem though is the skinny legs. I could go to the current ones that are heavier and need new streamlining etc. then it becomes even heavier ....bit of a rabbit hole chasing it all. Ken

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Thanks guys.. What do you advise me to do? I can easily fly it at 480 kg and show that the stall speed is ok.

But how can I demonstrate this if I am not allowed to fly it over 430?

Should I contact RAAus? Or should I forget about the whole thing and just keep operating as I always have.

Remember the plane had a placard of 480 kg for most of its life, and I have now been told this was illegal.

On your c of g with the bigger engine Ken, I like your thinking about moving things back to avoid adding lead ballast. How about a hatch in the underfin to carry emergency stuff like the beacon and spare tubes?

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Bruce, I could put my 2kg of tools there but I recon the beacon needs to be in the cockpit so can be activated as you are going down. Might be a little breazy shimmying along the fuzz to activate it! Probably best to keep to 500kg, move the battery and only lose 20-25 kg off my current useful load of 223.5kg. If I changed out my steam gauges for a flat screen that may save me 2kg, diet and lose another 3kg ( I aint fat) should give me about 200kg of useful load. Another trap for young players is to only use the jab timber prop as it is about 2.5 kg lighter than the bolly prop and is more important as it is way out the front so has more influence on W&B. Ken

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It is good to read that Sport Pilot is returning to our letter boxes soon. So with that news I raided the storage boxes in the shed and found some articles I wrote that may be of interest to those that hoard their magazines. November 2007, cover photo and article about our airspace. November 2008 about building and flying the first 100 hours. June 2009 about the cost of ownership and flying my Jab. Plane built with the help of Steve Biele and photos by Andrei Bezmylov.

 

I may update the articles and summit them for the new mag. Covid19 gives me time to sit home and do this. I have written a number of training publications for my work and they are more "do it like this or else" so I will have to work on my style a bit!

Ken

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Coz of Covid19 I did some searching on interstate flying by recreational aircraft. Found this on YouTube and tried to post the link but it won't do it on my iPad . If you look up - Low Level Survey Jabiru LSA 55 - it will show you how you will have to fly to avoid the rozzers. Bruce take note! Pity it is 10 years old, with the new cameras it would make for an exciting view.......too scary for me though. Ken

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Good point about the prop Ken. I was starting to think about changing but you have made me happy with the old wood one again. Also. have a look at a LiFe battery to save some weight.

Talking about flying the first 100 hours, it has been told to me that a cheap 6 volt ac plugpack connected to the tacho makes a Jabiru think the engine is at 3000 rpm and you get clock hours up for nothing.

Of course I did nothing of the sort.

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...I will have to put 8kg in the tail, yikes! So it will need the battery moved back to the rear curtain area to reduce this number...

Crikey that's a lot of weight!

Is it possible to relocate your tie-downs, toolkit etc way back in the fuselage?

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Relocating tools etc is an option but they then become part of the aircraft build as they form part of the empty W&B, if the W&B is too far forward without them you will always have to pack them. I guess it isn't any different than putting the tail weights in a glider. We had a SK jab here ( in my hangar for a number of years) that was approved for 544kg, but the CofG range was so narrow that tail weights had to be constantly monitored depending on pax weight . There are plenty of SPs around with a 3.3 with both 470 and 500kb auw. When I visited the factory on 2005 to buy my 2.2 version, Rod showed me an SP with both wing tanks and an internal fuzz tank as well (over 200 litres) when I asked how much it will max out at he was very noncommittal, I think he was going to organise his sock drawer as an escape. From my imperfect memory it belonged to a relative of a staff member.

I looked at the J200 but at 544kg it only left about 195kg for pax and fuel. My little SP has 226.5 of load. All this with a J200 may change with the weight increase. What I can't get over is that a number of VH j400 get to weigh 600kg when they convert to RAAus but the exact same j200s are stuck at 544.....go figure!

Ken

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The last one is easy I think Ken. As a VH aircraft, the J400 does not have a stall speed limit but it does if RAAus. It goes to prove though that there is no structural limitation.

I didn't know about that SK at 544. gosh that's a lot compared to my 430.

Where is it now? How did it go from 430 to 544? In the light of that SK, would they not look silly if they prosecuted me for flying at say 460?

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Bruce, it was eventually sold on to a person on the eastern seaboard. I did see it for sale about a year ago. the rego was 19-7474 (i think)

A J400 has a weight of 700kg but when many converted to RAAus they reverted to 600. They stall at about 50kts at this weight. to stall at 45 they have to weigh 544. RAAus probably accepted the experimental builder's word about 45 and left it at that. Look at pictures for both models and look at the placards. most older J400 conversions are placarded at 600 while J200 are placarded at 544, most interesting. I would like to hear from any J200 builders who have 600. I am waiting for the hate mail to keep my mouth shut!

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For what it’s worth

I’m in the uk with a savannah vg fitted with a jab 2200 engine no 22A2958 a while ago I experience a problem with no.1 cyclinder not work, I chocked for a spark at both plugs, carried out bot types of compression test (no.1 cylinder was approx 10psi up on the other three) stripped and found no fault with the carb and after much head scratching called in the uk jabiru guru Keven Hymen would turned up pulled my engine out of the air frame and left.

A long time later he told me the hydraulic tappers were not working properly (how did I get such good compression?) and overhauled the head and valve timing gear replacing the exhaust valves ( I can now run on 95 Ron unleaded). When the engine was refitted it now runs like a Switz sewing machine (purrs like a kitten).

Moral of the story it pays to ask an expert.

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Rendrag, good to hear you are back in the air again. Just wondering about the numbers your Savannah puts out regarding cruise revs and speed, what prop you are turning and litres per hour?

I haven't seen a Jab powered Sav in Oz but there are a few 701s, that seem to cruise at about 73 kts with the Jab 38" pitch wooden prop.

Derekliston may be able to enlighten us?

Ken

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