fly_tornado Posted December 16, 2014 Share Posted December 16, 2014 another one where the Jab lost power http://aircrashed.com/cause/cERA09LA356.shtml Link to comment Share on other sites More sharing options...
Oscar Posted December 16, 2014 Share Posted December 16, 2014 Additionally as a comparison the higher than normal fatal count in the Cirrus type aircraft in the US which has a far more exotic composite fuselage structure that does the Jab. Of course, what is being stated here is the advantages of the Jabiru use of a 'low-tech' composite structure that is afforded within the weight limits by the use of a light engine in a resilient structure vs. a heavier engine that necessitates a compromises in the resilience of the airframe to remain with the same weight limit. The difference between 'strength' and 'resilience' of a structure is critical to occupant safety - it is the essential reason behind road vehicle crumple-zones, for instance. It's a difficult concept for some to grasp. Link to comment Share on other sites More sharing options...
alf jessup Posted December 16, 2014 Share Posted December 16, 2014 Yes, yes, but would it be safe with a Jabiru engine? Totally safe, even the 6 cylinder wouldn't get it off the deck 2 Link to comment Share on other sites More sharing options...
Oscar Posted December 16, 2014 Share Posted December 16, 2014 another one where the Jab lost powerhttp://aircrashed.com/cause/cERA09LA356.shtml Immediately after takeoff, a reduction in engine power was observed. Power then increased, followed by another power reduction and the airplane stopped climbing. The pilot initiated a right-hand turn back toward the airstrip. One witness reported that the engine completely lost power. While in the turn, the witnesses observed the airplane stall and enter a spin at about 100 feet above ground level, from which it impacted the ground. Not a Jab airframe, which is the subject of this run of postings. Also, the engine was tested post-crash: The engine started on the first attempt. White smoke was initially observed from the exhaust, which cleared in two to three seconds. The engine ran smoothly and without hesitation. A total of four engine runs were performed, each approximately two to three minutes in duration. A peak engine speed of 2,830 RPM was achieved with normal oil pressure readings. The engine examination did not reveal any evidence of a malfunction or failure. There was no fuel in the carburetor bowl; however the engine remained inverted overnight prior to the examination. The air filter was clean and the spark plugs were normal in appearance. The smell of fuel was apparent in the area of the main wreckage and the ground was oil-soaked under the engine. The fuel shut-off valve was found in an intermediate position (not on or off) and there was no detent for the handle A classic turn-back/stall/spin accident, not in a Jabiru airframe, with a Jabiru engine that was found to be running entirely according to spec. post-crash. Most likely scenario, given that this was running on mogas, is either vapour lock with an ambient of 30C or fuel starvation due to incorrect fuel valve selection.. 3 1 Link to comment Share on other sites More sharing options...
motzartmerv Posted December 16, 2014 Share Posted December 16, 2014 Stopping on takeoff, in spec? ...We differ in opinion there..:) Link to comment Share on other sites More sharing options...
fly_tornado Posted December 16, 2014 Share Posted December 16, 2014 I was only reporting the facts Oscar, you can determine you own conclusions. The way the FAA licences homebuilts makes it very hard to find Jabiru engines, you need to search through every accident and cross reference with registration database and this isn't always complete. Link to comment Share on other sites More sharing options...
biggles Posted December 16, 2014 Share Posted December 16, 2014 Stopping on takeoff, in spec? ...We differ in opinion there..:) A fuel shut-off valve not fully ported is unlikely to supply sufficient fuel for a safe climb out . Bob Link to comment Share on other sites More sharing options...
Oscar Posted December 16, 2014 Share Posted December 16, 2014 Stopping on takeoff, in spec? ...We differ in opinion there..:) The engine started on the first attempt. White smoke was initially observed from the exhaust, which cleared in two to three seconds. The engine ran smoothly and without hesitation. A total of four engine runs were performed, each approximately two to three minutes in duration. A peak engine speed of 2,830 RPM was achieved with normal oil pressure readings. The engine examination did not reveal any evidence of a malfunction or failure. The engine examination did not reveal any evidence of a malfunction or failure. I quote the evidence presented, Merv. You are, as always, at liberty to place your view of the facts for the consideration of the forum members. I would expect nothing less! Link to comment Share on other sites More sharing options...
facthunter Posted December 16, 2014 Share Posted December 16, 2014 There's a large percentage of EFATO caused by incorrect fuel selection. Probably MOST in GA were from that cause when last I looked. IF the engine runs on spec after the failure , wouldn't it make you suspect something ancilliary to the engine caused the failure.? Nev 2 Link to comment Share on other sites More sharing options...
motzartmerv Posted December 16, 2014 Share Posted December 16, 2014 Was the cause found in the investigation? I cant see it there. So when a cause IS NOT found, lets just start by seeing if we can blame the pilot. You sure you dont work for this company? https://www.youtube.com/watch?v=Jxqlf_mrCso Link to comment Share on other sites More sharing options...
facthunter Posted December 16, 2014 Share Posted December 16, 2014 There could be some fault in the fuel system. IF the engine is still alright it is still alright. It's normal to do post crash examinations like this and arrive at conclusions from them, regardless of the make of engine. In one prang with a Jabiru in the USA they found the carb had experienced a dashpot piston jammed at full open, and falsely concluded it would have gone to excessively RICH (which is not the case). It's the same type and brand used on both motors we talk about which at the moment have a problem with the material the floats are made from, but they can't supply one that doesn't have the problem as a possibility, or tell you how long a new one might last. Nev Link to comment Share on other sites More sharing options...
fly_tornado Posted December 16, 2014 Share Posted December 16, 2014 The photos of that crash show a fairly hard impact into the ground. Can I clarify? There is only a single tank in a tornado, the fuel is driven to the engine via an electrical or mechanical pump, its either on or off. The lever they refer to is the sump drain, its more than likely that the impact with the ground dislodged the lever. Link to comment Share on other sites More sharing options...
Oscar Posted December 16, 2014 Share Posted December 16, 2014 I don't even LIKE rum, Merv - though I could almost move to Bundy just for ready access to the local prawns.... And, after some consideration, some distance to some of the totally raw prawns in my current locality. 1 Link to comment Share on other sites More sharing options...
biggles Posted December 16, 2014 Share Posted December 16, 2014 The photos of that crash show a fairly hard impact into the ground.Can I clarify? There is only a single tank in a tornado, the fuel is driven to the engine via an electrical or mechanical pump, its either on or off. The lever they refer to is the sump drain, its more than likely that the impact with the ground dislodged the lever. What " lever " ? The investigation report clearly refers to " the fuel shut-off valve ...... " Link to comment Share on other sites More sharing options...
Guest Ornis Posted December 16, 2014 Share Posted December 16, 2014 A friend of mine with a J200 (built at a glider factory for the then NZ agent) had persistent engine hesitations on take-off/climb-out and no other time. He eventually fitted a new carburettor and the problem did not recur. He then fitted Rotec water-cooled heads but by then he didn't trust the engine so is fitting a Rotax 912S. Link to comment Share on other sites More sharing options...
fly_tornado Posted December 16, 2014 Share Posted December 16, 2014 There's no fuel shut off valve in a tornado, its a drain. Link to comment Share on other sites More sharing options...
Oscar Posted December 16, 2014 Share Posted December 16, 2014 There's no fuel shut off valve in a tornado, its a drain. So - if it's half-open, the fuel pump sucks a mixture of air and fuel? Hey - not likely to produce problems in full-power take-off, obviously. Remind me, please, not to fly in a Tornado, or listen to one. 1 Link to comment Share on other sites More sharing options...
fly_tornado Posted December 16, 2014 Share Posted December 16, 2014 Oscar, the fuel isn't in the wings its behind the passenger seat. Tornados use an inline filter either on the end of the fuel pipe that sits just off the bottom of the tank or an inline one and feeds directly into the fuel pump. Trust me on this Oscar, it was the engine not the fuel tap that caused the plane to crash. Link to comment Share on other sites More sharing options...
motzartmerv Posted December 16, 2014 Share Posted December 16, 2014 And, after some consideration, some distance to some of the totally raw prawns in my current locality. If you have a raw prawn problem, I would reckon its operator error. You need to apply the prawns to a significant source of heat to exite the molecules and "cook" them. Im sure its in the manual somewhere.. Link to comment Share on other sites More sharing options...
Oscar Posted December 16, 2014 Share Posted December 16, 2014 Oscar, the fuel isn't in the wings its behind the passenger seat. Tornados use an inline filter either on the end of the fuel pipe that sits just off the bottom of the tank or an inline one and feeds directly into the fuel pump.Trust me on this Oscar, it was the engine not the fuel tap that caused the plane to crash. Nope, I don't trust you. Nor does the authority who investigated the crash. 1 Link to comment Share on other sites More sharing options...
fly_tornado Posted December 16, 2014 Share Posted December 16, 2014 I'm really hurt by that lack of trust Oscar 1 Link to comment Share on other sites More sharing options...
Oscar Posted December 16, 2014 Share Posted December 16, 2014 If you have a raw prawn problem, I would reckon its operator error. You need to apply the prawns to a significant source of heat to exite the molecules and "cook" them.Im sure its in the manual somewhere.. Merv, I do believe you are correct. The prawn(s) in question provide only heat rather than light to any debate on Jabiru engines, but somehow manage to only turn scarlet rather than palatable. Somewhat of a pity, as a prawn cocktail is a pleasure on a hot evening by the barbeque, yet these prawns provide merely tales from the perspective of total cocks rather than digestible goodies. Link to comment Share on other sites More sharing options...
Oscar Posted December 16, 2014 Share Posted December 16, 2014 I'm really hurt by that lack of trust Oscar Jeez, you must be used to it by now, FT.... Link to comment Share on other sites More sharing options...
fly_tornado Posted December 16, 2014 Share Posted December 16, 2014 I respect what you do Oscar. Link to comment Share on other sites More sharing options...
biggles Posted December 16, 2014 Share Posted December 16, 2014 Oscar, the fuel isn't in the wings its behind the passenger seat. Tornados use an inline filter either on the end of the fuel pipe that sits just off the bottom of the tank or an inline one and feeds directly into the fuel pump.Trust me on this Oscar, it was the engine not the fuel tap that caused the plane to crash. FT , I'm sure that an FAA inspector knows the difference between a sump drain and a fuel shut -off valve , so ,if the inspector/investigator says its a fuel shut- off valve , then that's precisely what it is ! Bob Link to comment Share on other sites More sharing options...
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