RFguy

maybe some issue with a combination of higher vibration (low RPM) and less than perfect crimped connectors. someone must know at factory.

Howdy I've heard of this from an aircraft on the sunshine coast. cant remember which.. I would be sure rotax have a diagnostic log in their box. This will contain the info.... Many engine shops, not sure about Berts, are generally low tech affairs and shy away from this data.... Talk to the factory . is this at low idle or moderate power ? gather in a flare so it is occurring at idle stop ? - glen

Mark, BTW according to Mr Factory Rotax (at the show) , while 912, 914, 915 are similar beasts, 916 is new crankcase, new gearbox, new turbo. .....also, old turbo in 914 is no longer available. Has your S21 got the big bore 912ULS in it at 10.5:1 ?

How about gearbox compatibility ?

For those wanting a different wing, a wing change would require a lot of engineering and test. I think the existing wing is fine. If you want a shorter landing airplane, just get the drag up. there is a way to do this. (apart from ensuring your idle speed is lowest possible/safe) Jabiru actually reduced the flap max deflection in its aircraft 2007 ish because it was found that it didnt provide anymore lift, just more drag, and that it wouldnt climb in a go around terribly well at max flap.... I think that extra drag is definitely useful to reduce landing distances, and will modify my aircraft I think (move the flap motor stops ) . Sure it wont climb easily in a go around at the max flap , but neither will my part91 certified aircraft. I know another owner that used the extra available unused motor travel to reflex the flaps, for slightly higher cruise speed.... but it turns out the most drag at cruise is not the wing but the nose and the gaps and the mains. -glen

Well , deadly silence from Jabiru upon the question this morning amongst other correspondance. Must be true. Maybe I will keep my J230 and finish the rotax conversion. (need to do a customized exhaust system, or just use straight pipes out the side) . Maybe inject some avgas into the outlet pipes for effect instead of the strobes.

Today, in email conversation with Jabiru regarding current engine delivery (about 9 months for a Gen 4 3300 is the answer) I have asked the question about the company sale.... No response, so far. We'll see.

The air is different in Europe, the air they breath and fly in is denser by being subsidised as extra 0.3kg per cubic meter by taxpayers , leading to a lack of world competetiveness, and aircraft that can only meet their specifications in european air.

Hi Mark I see some aircraft have BRS fitted behind the instrument panel.... Is the S21 Conty mount just for a generic continental, or is there something specific about a Titan 340cu" ?

I might add on the Va thing, while its accepted Va can calculated by taking the clean stall speed multiplied by the squareroot of the load factor, In the example I used above of the ATEC, that was the designed load factor (3.8g normal category ). HOWEVER If the aircraft did not break say until 8g, then the designer might use that value in the calculation of Va (but the FAA might not like it) . In the book , Faeta NG is given at 600kg, Vs1 of 40 kts. and 4G limit. which implies a Va of sqrt(4) * 40 = 80 kts. If the aircraft didnt actually fail until say, 8G, the mfr might write down 113 kts. That might be OK for LSA, but for a Part 91 aircraft , the FAA wouldnt accept that (is my reading).

I imagine they'll move prop maybe forward, battery forward , oil tank fwd etc etc all the usual. The TAS is good, Mark. 10,000'. Well like I always say, if you fly low you are leaving TAS on the table. (said from a cross country flyer's perspective). Mike when are you back in Australia ? Stuart and I will make a trip to see you. cheers,

yeah 915 is better because there is a turbocharger there.... but hard to go past an O320, surely ??? (or was it a 235 you were looking at ? ) what about CG Mark- do they need to move the propellor location forward to get the same CG range ? (IE without that paperweight Lyco-conty on the front) ? or is the paperweight actually too heavy (or suboptimal) for it ?

I expect they would sell a ton of J230 airframes with a 3 blade 912ULS in them. and 914/915 as a upmarket option. although these days, there are many composite competitors snapping at their heels. It's not a complete shoe-in. assuming same thrustline and prop location (as I had), cowling needs to be bulged a bit on front lower to accomodate the exhaust headers from the front two cylinders.. not too much work really.

I suspect a few high profile failures at this stage of market penetration could be curtains for UL, unfortunately. Yeah, Jab engines with Jab factory props (whether wood or composite) give a statistically insignificant number of reported problems. Ever seen the big bearing at the front of a lycoming ? a few inches long ! There is a reason for this... Jab also put alignment-fixing dowels onto the crankshaft-prop flange sometime around 2013, also. So something must have been amiss that we didnt hear much about.

I'd absolutely suggest using a Lyco or a Conty. The UL while similar to the Jab, it doesn't have much case time compared to the Jab which hasnt changed in the bottom end for a long time..... Jabs bottom ends dont give any problem unless their thru bolts break or are not correctly fastened (assuming initial assembly was good) . I'd suggest for others a low cost on-condition post TBO Lyco is still a better bet, if the aircraft can deal with the extra weight, which can be reduced with electronic magnetos, getting rid of the vaccum pump, lightened exhaust system, lightened rocker covers etc etc. I would be HIGHLY surprised if the Airmaster was suitable for the UL, since the moment of inertia is miles beyond the listed limit for the Jab engines, and the bearing setup is similar.

If I assume it is a normal category aircraft (3.8g) at MTOW, and the clean stall is 39 kts at 585kg, then the ATEC faeta ..... Va is 76 knots. (@MTOW J230D is ~92 kts) So you better slow down if you don't want to overstress the airframe. Saying that I would still like to own one of these aircraft for high speed, low cost commuting. anyway this forum is about the JABIRU SALE.

yeah adjustable seats are done by swapping out various under your butt + behind your back foam/cushion combos......

SKippy, Jabirus are fine. I think I have to slap you with those remarks. Push pull controls need very little maintenance. The whole floor , covers, and rear has to be pulled up in my PIper to inspect the myriad of cables, wires, pulleys, wheels turnbuckles etc etc Stall speed is fine. 40 knots is fine. ANything slower than that and unless your technique is good and you have a giant rudderm, crosswinds will be MUCH more of an issue for a pilot of average ability. Slow is not always good. Wing is fast enough and is very efficient. You will not go much faster than they do for a given stall speed and airframe weight . The Jabiru is about as good as it gets. sure could have a tidy up on gap seals etc, but it isnt much . Lower stall speed is an issue if you want to go fast because Va is proportional to stall speed. This means if it is ever bumpy, you will have to fly MUCH slower otherwise the aircraft will be overstressed. Sure yoru Faeta will cruise at 125 k, but it has to slow down to like 70 k if it gets bumpy !

yep, you can buy a 912ULS core for 28k. all accessories if you buy rotax (expensive) ones brings it to mid 30s, I think. But you get 2000 hours TBO without touching it , almost. Still , I don't hear too many gen4s blowing up these days, either. Hopefully, New Jabiru will offer Rotax powerplant for their aircraft. They'd sell alot of J230 hulls. They might outdo C172s.

update. on the HDX performing a CDI (course deviation indicator) function . using an ARINC429 interface (a type of aviation instrument bus) between a WASS GPS IFR approved navigator (like 430, 530, 175 , 375 etc) the HDX skyview is FAA approved for IFR for using the CDI function in the Skyview. That is, no discrete CDI required in that case. (according to the manufacturer in writing) .

well, an RPL and class 2 BASIC medical is a pretty easy conversion. This leaves the issue for aircraft that can fly at 700kg (J230) but are placarded to 600kg. and.. what are the pathways for uprating an existing factory LSA. Can it be done by re writing the placard and turning it into a 24-experimental via an MARAP ? (I wouldnt recommend at J230 > 700kg because I think the mains are not up to the increased landing speed energy having seen two broken now on others landing downwind)

I would think those numbers are within the normal range of the test precision. Sounds fine. If you get low leakdowns , WHY is just as important as the numbers to whether or not it is airworthy. Tank gurgles are normal. For a high hour 914, good numbers- nothing to be concerned about at all. Many rotax go 3000 hours+ without rings being done. Check if the leaks are happening on the exhaust valves- there was a SERVICE BULLETIN for 914 on the exhaust valves (in recent times) . Footnote- For Jabiru- Jabiru engine are not tolerant to brewing troubles like other engines. For Jabiru- Suggest investigating the WHY if leakdowns are lower than 70, and ground the aircraft if lower than 60. A leakdown lower than 60 on a Jabiru engine may indicate imminent engine failure will occur. (valves not closing (and will separate) , stuck/ broken rings, cracked piston)

And you wouldnt reach the pitch trim wheel in that condition in the 172...... (compared to rearward located trim in the Archer) .

KG- sounds like an ordeal you would rather not revisit.... So does the Cessna go that far back for what purpose ? In my Archer, full seat back would be still flyable, just a little bit of a stretch- Although I am tall and lanky so I have long reach....

interesting. I clearly have something to learn. so.. just how far do you end back if the seat goes back ?