RFguy

Bruce the main error is the lack of a battery isolation relay/contactor at the battery. Needs to be an enclosed contactor (no free air spark) . every certified aircraft I've looked at is done this way. The factory has the hot battery wire goes into the cockpit wiring mess. same for alternator- needs to be fused and have its own wiring in the engine bay. alternator generators enough energy to make a fire also, but the battery is the king fire generator. needs a fuse between battery and alternator chargign output. regulator goes bad and puts battery V+ onto the shorted stator. woof.

dunno, I'd do some reading... others might be able to advise. there might be some minimum temperature it has to be at to operate correctly, and location might influence that.

I would not blame the pilot- it is a helicopter !. to stay airborne you just need to put in enough rudder, balance pitch and roll, and pull on enough collective. how hard can it be. so, no I do not think it was the pilot. Jabiru's likely burn because of their haphazard, dangerous wiring practices, and poorly engineering wiring paths (happy to stand in a court of law with that one) . there is no way those airframes should fly without electrical mods. IMO. I have commented to Jabiru about it with no response.

home owner and neighbours are fortunate that there wasnt a fire.

I've had the jabiru ice up on the ground at high idle on a foggy cold morning. ...

rightio then , sounds like just needs methodical approach to figure out what is going on. Yeah the O2 sensor (ULP only - no lead) would be a handy diagnostic I think.

This is a good read https://www.rotax-owner.com/pdf/UNDERSTANDING THE 914 ROTAX.pdf Particularly sections : the ENRICHER SOLENOID SECTION (9) and FUEL REGULATOR- AIR BOX PRESSURE (14) Rudder - take a good look at those two sections. I reckon you will find your demon there.

Carb heat is common oncarbed Rotax, Brendan, depends on manufacturers implementation of WHERE they get the inlet air from. Most Tecnam seem to have dual air filters on the carbs inside the engine bay. so, somewhat preheated air. You'd want carb heat if deriving inlet air fresh from front of aircraft. disadvantage of internal air source is you leave performance on the table with the warmer air intake . rudder, I'd suggest persisting in finding the problem. I'd be looking for the enrichment circuit sticking, or carbs not well balanced in those RPM ranges. After thoroughly cleaning all the plugs, did the behaviour change ? The 914 runs tricks on the carb bowl pressure when in boost. at MAP28- that's a transiiton area where you like are starting to get the boost of coming online. Maybe the float bowl pressure boost compensation is not working currectly. Is it generally smooth at any setting where there is a couple of inches of boost ?

if you have not as yet, do consult the book on recommended loading (manifold pressure, fuel flow ) versus RPM in the 914 ops manual,

iT'S SUCH A LOAD OF CRAP, JUST DID IT. Remember the try on by the gov back in the 80s- the "Australia Card" and they got rejected. So then they just came up with the ATO TFN instead as the number...

mmm dunno that will help that much you can get an idea of mixture just from the EGTs ... what did you find re my above questions ?

105C and 20 deg ambient ?. hmmm might be hot on a hot day. but all planes have similar issues.

what's the thermofan fan for ? airplanes generate plenty of airflow and pressure... rotax is happy for much higher temps than that. and if you let it get hotter, cooling effectiveness improves enormously (higher Tdiff) . IMO the airplane should have enough cowling airflow stationary at engine idle to deal with any heat it makes.

another gear up landing. gather the empenage buckled when the front of the airplane stopped. cant imagine the passengers bodies faired well to the decel.

Thanks CC for the nicely written input. I did have to look up "Azeotrope". My year 12 chemistry is a long time ago... An azeotrope is a mixture of compounds with the same composition in the vapour as in the liquid. In other words, an azeotrope is a liquid mixture that has a constant boiling point and whose vapour has the same composition as the liquid.

Yes, the ATEC Faeta is a very good plane, also. skip, we're talking INDICATED airspeed for this question. My guess is ur talking 115 kts indicated at 18lph (translate to 134 kts at 8.5kfeet) Looking at W&B limits , the Vixxen has a little more utility of you want to carry stuff (but is not as fast as the ATEC)

I've only flown the centre Y stick Vixxen. comfortable.

that's crap skippy, 18 lph with 106 kias indicated is excellent. I dont know any other plane that will make that and land slow. AND carry 100 litres of fuel AND two people and 25kg bags, comfortable cabin width etc. SKippy, please list the airplane you speak of, and its useable load, endurance, cabin width etc

right. good one. so its not that the ULP goes stale, more that it becomes contaminated and changes, and develops unwanted characterists and afterproducts. The single Kwinana pipeline. golly. LOL. Seems the overiding advice is for bowser ULP- test if possible and otherwise immediately. and with AVGAS, we are paying for some care with the fuel. I've still heard plenty of suspect AVGAS stories. So what's the purity like then of "bulkfuel" (ULP) ? I guess you give yourself a fighting chance, depending on the supply chain, how it was bottled etc.

yeah. it's cruise speed is down though. the Vixxen can walk AND chew gum.

anyways ........ discussion is on truth or myth stale ULP. My current thinking is that the ULP becomes contaiminated by aircraft tanks, ethanol, etc

Kevin The LSA airplane I have liked most so far is the Aeroprakt A32 Vixxen. that is quite an impressive airplane. lands in the low 30s, heaps of rudder autho, 106 kts indicated at 18 lph , climbs like a scalded cat (for its category) . 5 hours of endurance and heaps of load capacity. That would be the plane I would buy if I had some coin.

Nice writeup OneTrack . Thanks for the effort on that major treatment.

I bring up the question on compatibility with the detergents, volatiles and additives question because of what I saw last weekend in the banana milkshake fuel drop (same colour as the tank) ! I have seen a fuel drop in same tank type from avgas sitting around in it with no such effect. Onetrack : IYO , How likely is ethanol fuel contamination into the premium unleaded fuel station supply ? If its not ethanol attacking the tank, then what is ?

Generally there is discussion on whether fibreglass tanks are ethanol compatible. I wonder if there is any issue with volatiles and detergent compatibility with said tanks , also. Note bulk fuel you can just buy 95 PULP, without the detergents and other marketing additives. That's probably what I would choose sans extra research.