RFguy

and I beleive that the fuel returns for the rotax need to go from T jets at the carburettor fuel inputs, not at the fuel pump output ... the fuel pump gets a good air blast, but it can be pretty damn hot in the fuel line running over the top of the engine which is very crowded and hot. hence the returns at the carbs. Also, the float bowls need heat shields. (IMO) many aircraft have drip trays under the carbs which function well as shields. I would always have the fuel overflow/etc pipe not drip into the tray like some aircraft I see with a drain pipe on the drain . jesus no, needs to go out in a pipe away from the exhaust pipe. otherwise just what you need a drip tray full of fuel !

It's a check to understand / know the engine output / workload, along with MAP. RPM and throttle position might mean nothing without MAP and fuel flow.

There are quite a few like this, but I am not sure I like having a couple of $1 cogs in my aircraft fuel flow. - not sure if the cog stops it blocks flow??? or is there a minimum pressure to get flow ?. The OF05ZAT-AR series look OK. - you could use two in parallel, that's probably safe enough. (and you'd need some indication that one got stuck so you knew one was down) Now, also the common Red Cube sender is not immune from failure, either. https://www.supercub.org/forum/showthread.php?60571-Inside-your-Red-Cube-fuel-transducer-(mine-failed) post #29 is interest. worth while reading through the forum thread. the chink one : https://www.aliexpress.com/item/32814415226.html?spm=a2g0o.productlist.main.81.bc6c91fdfaX391&algo_pvid=f9b1cb7c-92d2-482e-b80c-7282caccc20f&algo_exp_id=f9b1cb7c-92d2-482e-b80c-7282caccc20f-40&pdp_ext_f={"sku_id"%3A"64598145468"}&pdp_npi=2%40dis!AUD!32.89!16.44!!!!!%402102111816733838903893115d0688!64598145468!sea&curPageLogUid=qyCzyEZ9FMjR and : https://www.aliexpress.com/item/1005004429310822.html?spm=a2g0o.productlist.main.107.bc6c91fdfaX391&algo_pvid=f9b1cb7c-92d2-482e-b80c-7282caccc20f&algo_exp_id=f9b1cb7c-92d2-482e-b80c-7282caccc20f-53&pdp_ext_f={"sku_id"%3A"12000029156016190"}&pdp_npi=2%40dis!AUD!19.28!16.39!!!!!%402102111816733838903893115d0688!12000029156016190!sea&curPageLogUid=WUWYIauRLTLI

They're OK from a design POV.... Your mileage is very much LUCK. mine are OK ... Quality varies enormously. whether or not a wire got pinched during assembly to cause trouble 5 years down the track...... balls of solder rolling around, passive chip components failing likely due to assembly/mechanical stresses. the rigidity of the enclosure is really not quite good enough for surface mount parts. and the factory alignment of the receiver appears to be COMPLETELY wrong.. OMG what were they thinking. It's like the original designer got the design 90% done and built a prototype and then left or died, leaving the company to guess the rest. I've seen it alot in professional circles..

waiting on parts... the great semiconductor shortage. uses separate chassis for guts and display, however does also have same DB25 connector as microair so it's plug and play. (there's an adaptor board to imitate different radios ). yes idea is to listen to CTAF, CENTRE, AWIS simultaneously (1..3 orders priority of either mix or which one you hear) + 1 x UHF (on same airband antenna) . Idea is that local CTAF overides AWIS etc when in circuit. Various cool stuff like pushbutton time limited temporary low power so you'll only be heard a couple of nm (or less if you want) if you only want to talk to an aircraft in circuit (and not blat all over the place) , digital RF noise blanker (goodbye ignition noise) , auto volume levellers (fixes quiet and loud people) . actually the radio can do 16 channels simultaneously but what would you do with that ?

From my perspective : -Jabirus tend to have hard failures (engine stops - but usually there will have been maintenance canary in the cage warning unheeded) . Jabiru could be more communicative / proactive so people didnt find out their flywheel fell off and Jabiru knew they were falling off... -Rotaxes seem to have more nuisance failures that are unlikely to down the airplane unless they distract the pilot. (multiple carb linkages /cables for choke+throttle etc are generally trouble unless done right leaving one side rich/unbalanced), ignition module failures, behaviour of engine and richness at low gas velocities, coolant leaks + radiator expansion cap problems, oil leaks or oil pressure issues (usually due to wrong installation) , yes, both throw pistons.

I think there is little point looking at RAAaus registered engine fail stats because there is very little data and even smaller reliable data. It's unfair to compare apples and oranges, --IE Lycomings are in majority in certified GA airplanes with strict maintenance and AD regimes and a reporting structure . -- Jabirus + Rotax are mostly in LSA or experimental aircraft with highly variable maintenance standards and program, and no AD regime and loose/no reporting structure.. in both cases, putting aside the variability of the quality of aviation mechanics, which is about as bad as any industry.

Hi Peter Well, if you know something that could be useful to future safe (er) operation of aircraft, I'd encourage you to write to the technical manager at RAAus with any useful information . -glen

does the ATSB have court of law style compel-to-answer style powers ?

If I ran for RA board, driving change for the way accident investigation was done would be my #1 bullet.

if it was a PA28 then the accident would be investigated thoroughly . I suspect part of the reason for the speculation in 4 pages here is that in general , in RAaus, the cause of an accident is never truly got to the bottom of ...

For those interested in aircraft accidents and engine fialures, last months kitplanes article is a good one https://www.kitplanes.com/homebuilt-accidents-passing-the-engine-baton/ I would suggest a digital subscription to Kitplanes is an excellent and affordable choice for everybody who finds this article useful.

mmm well... LSA55 - I have ~ 9 hours in them in dual, they are not lacking in power- they're quite light (240kg ish) , I would describe them as a real sports car...... I have taken off ( at Coonamble at OAT = 36 with FULL FUEL (just refueled) and 2 x PAX) and NO ISSUES with good rate of climb. even at 40 OAT should get airborne just fine, so I *guess* some other mitigating factor. compare to something like a J160 which has about the same amount of wing (and similar wing) and quite a bit heavier (540) at OAT = 38 and PA = 0, 540kg= climb = 461 fpm, 440kg - 700 fpm.

anyway, Pilot of that Jab, if you are listening, we would love to hear the story.

Jab's are fine. Gen1,2,3 : do not fly with leakdowns < 65/80 or CHT > 160C or EGT > (770 - fuel flow percentage). (EGT values for air cooled heads) 40 deg C, 'sea level ' density altitude is 3000' ! .... and if there was a low overhead, add another 300 feet maybe.... so performance is down about 20% ! add to this higher chances of ULP (?) fuel vapourization (was fuel pump turned on in takeoff to pressurize the lines etc ) ?? etc etc so it probably has a climb rate of 400 hundred feet a minute two up.... at best then to all that- add a thermal SINK , for example...... (OME the thing hanging out is the oil catch can)

It's a good reason NOT to paint your Jabiru anything other than glossy WHITE - the glass temperature of the structure could be approached on a hot day sitting on the ground.

golly you two stop it... at the end of the day, the PIC makes the call. If the PIC goes outside the parameters and limits set out in the POH for that airframe then they better be able to convincingly explain their reasoning and method.

right. Oh well, just hope that the engine or fuel system is pulled apart by someone familiar so that what happened 1st, then what happened 2nd etc can get hypothesised. I would love to ask the pilot the 1000 questions.

well a 3300 missing one pot can (usually) still make enough power to maintain altitude, so something might have happened that affected the whole lot (or more than one)

airframe held together well enough, as usual... good outcome.... hope the engine is pulled apart by someone who knows what to look for what to report on, so something can be learned.

Is the low sun going to be a factor at any end point / location ?

thanks Nev. I will do some accurate measuring... ironically, it's cheaper for me to just go and buy a new set of pistons than refurbishing this set of 6, however, then I wouldnt get much benefit about learning the process- although I've already done that once. pressure cooker, MEK soak, ultrasonic cleaning, nylon and brass rotating brushes then finally ring lands with broken ring... that was last time, probably half a day a piston.

I use one of those with a bit of string knoted to the middle... VERY fast to use.

yes, always try a test piece. Dishwasher tablets- Sodium Hydroxide - deadly on aluminium. but good for cleaning up valve steams....

Hear say is a that 100% ethylene glycol in a pressure cooker makes a great carbon remover for parts also... Carbon Chemist, what's going on there ?