VH-PGW PA-31P-350 15 June 2010 Crash Investigation
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If he did it after takeoff he would never have got to the altitude he did. Also makes you wonder why, if that was the case, he didn't change back to the main tanks when he had a problem... but we will never know.
KRUSTY 34
Yer your right "The fuel system was simple Left and Right, 80 us gallons up to the tabs, 95 us gallons was up to top of the wing and then full tanks was 119 us gallons aside." found that here http://www.pprune.org/dg-p-general-a...1p-mojave.html
Is JetA1 heavier then Avgas? Maybe topped it off and it all sunk to the bottom of the tanks or something?
Ol' Ivesy must be desperate if he's got DeBruins' J32 in
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Is JetA1 heavier then Avgas? Maybe topped it off and it all sunk to the bottom the tanks or something
I am not saying that PGW had Jet A1 in its tanks in this instance but there seem to be similarities to the incident I speak of in some of the evidence arising from some witnesses to the way the remaining engine was delivering power.
Despite the difference in specific gravity it seems to float on the AVGAS with a layer that does mix to a certain extent, which seems to allow an aircraft to get airbourne with the inevitable power degradation (when the engine is trying to digest the cocktail of Avgas and Jet A1 it still runs, however belches smoke and runs very rough) sometime later.
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Hi Les,
Sounds like a possibility, eye witnesses said the other engine was cutting in and out possible detonation? does anybody know the company's sops maybe engine failure due to running the engines too lean like the one over in Adelaide can't remember the details off hand,
Sounds like a possibility, eye witnesses said the other engine was cutting in and out possible detonation? does anybody know the company's sops maybe engine failure due to running the engines too lean like the one over in Adelaide can't remember the details off hand,
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Mis-fuelling does seem like a pretty obvious scenario, although the problem is that Jet A-1 is heavier than Avgas (.8 to .71), so it really should have got into the fuel lines pretty early in the piece. The other problem is that it should be very simple to establish what went into the wings, it should have been known within hours of the accident and yet CASA have said nothing about it. Unless, of course, the refueller is trying to cover his arse...
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I'm aware of the 210 incident, and that engine was very badly damaged. It did fly for a short time after refuelling. I expect he changed fuel tanks during that time.
I know of another misfuelling incident (with avtur instead of avgas). In this case the aircraft took off shortly after being refuelled and the engine failed shortly after liftoff and they landed on a road.
I expet any avtur in the tank that is supplying the engine would result in immediate failure. If it (the PA31P) was misfuelled there will be records of that.
Regarding the engine surging. This could be caused by interruption of the fuel supply to the engine. When that happens the prop goes to full fine, and unless the throttle is retarded the engine will go to max RPM when the supply is restored, and then reduce to what it was as the prop pitch changes. (don't ask me how i know)
I know of another misfuelling incident (with avtur instead of avgas). In this case the aircraft took off shortly after being refuelled and the engine failed shortly after liftoff and they landed on a road.
I expet any avtur in the tank that is supplying the engine would result in immediate failure. If it (the PA31P) was misfuelled there will be records of that.
Regarding the engine surging. This could be caused by interruption of the fuel supply to the engine. When that happens the prop goes to full fine, and unless the throttle is retarded the engine will go to max RPM when the supply is restored, and then reduce to what it was as the prop pitch changes. (don't ask me how i know)
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Nope... don't happen to have one of those. However it is basically the same shape as the wing between the spars, one big tank each side. The dihedral is the reason that, once separated, mixing tends to be inhibited.
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Mmm..playing devil's advocate here but wouldn't the turns onto course and then the vibration of the engines cause the fuel mix to stay mixed?
Like bushy, I am also aware of the 210 crash in Central Australia. The story I was told was that the pilot misfueled the aircraft from drum stock while doing a mail run. The engine started running rough almost immediately on starting. The pilot shut down and phoned the engineers who advised remaining where he was but he thought he would travel another sector (for what reason I have no idea). The engine seized (I think) forcing a landing into scrub.
Like bushy, I am also aware of the 210 crash in Central Australia. The story I was told was that the pilot misfueled the aircraft from drum stock while doing a mail run. The engine started running rough almost immediately on starting. The pilot shut down and phoned the engineers who advised remaining where he was but he thought he would travel another sector (for what reason I have no idea). The engine seized (I think) forcing a landing into scrub.
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If the aircraft is in balanced flight, turns onto course will do absolutely nothing other than aid separation... the only slight help being the tiny amount of additional G in any turns, which will tend to force the higher SG (ie turbine) fuel to the bottom. Engine vibration, by itself, is highly unlikely to have much effect.
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Like bushy, I am also aware of the 210 crash in Central Australia. The story I was told was that the pilot misfueled the aircraft from drum stock while doing a mail run. The engine started running rough almost immediately on starting. The pilot shut down and phoned the engineers who advised remaining where he was but he thought he would travel another sector (for what reason I have no idea). The engine seized (I think) forcing a landing into scrub
I know diesel isn't avtur and unleaded isn't avgas but I believe they're similar enough for this story to be possibly relevant...
The old man filled our old petrol Peugeot 504 with diesel by mistake at a servo on the Hume Highway. He headed off down the highway as normal and several kilometres later, with no warning, it suddenly belched a large cloud of smoke and the engine stopped dead. There was no mixing of those fuels I can tell you.
To answer the replies below... the engine ran fine after the lines had been blown out and fuel introduced. There would not have been pre-detonation or anything like it. The diesel simply did not combust, however by coming into contact with the fuel in the lines a small amount of mixing occured in the fuel line, and the hot engine interior would have created some smoke from the diesel, enough to create a few seconds worth of clouds of white smoke from the exhaust. Pre-detonation occurs when you introduce a lighter grade of fuel into a diesel, as in petrol into a diesel, but not the other way around.
The old man filled our old petrol Peugeot 504 with diesel by mistake at a servo on the Hume Highway. He headed off down the highway as normal and several kilometres later, with no warning, it suddenly belched a large cloud of smoke and the engine stopped dead. There was no mixing of those fuels I can tell you.
To answer the replies below... the engine ran fine after the lines had been blown out and fuel introduced. There would not have been pre-detonation or anything like it. The diesel simply did not combust, however by coming into contact with the fuel in the lines a small amount of mixing occured in the fuel line, and the hot engine interior would have created some smoke from the diesel, enough to create a few seconds worth of clouds of white smoke from the exhaust. Pre-detonation occurs when you introduce a lighter grade of fuel into a diesel, as in petrol into a diesel, but not the other way around.
Last edited by nojwod; 13th Aug 2010 at 12:59.
'nojwod' there would have been some mixing, Jet & Avgas does mix otherwise turbines engines wouldn't be allowed to use Avgas (limited use) for engine combustion.
You might find that in yr dads case the car initially ran on the fuel in the fuel lines & carby (if it where a carby fed donk which I think the old 504 was) before the kero based fuel came into contact with the engines combustion chamber/s. When such an event happens the damage to the engine is nasty thru sever detonation problems causing failure of some moving parts within hence the 'dead stop'. The large cloud of smoke as you mention was the final explosion of the poor fuel/air mixture just prior to death of the 'Pug'.ugly things they where too.
The biggest diff between Avgas (petrol) & Avtur (Kero) is the liquids flash point not so much it's ability to mix. As most would know for an auto eng you need a much higher compression to support ignition using Diesel fuel where using petrol (Avgas) it can explode just looking at it!
Wmk2
You might find that in yr dads case the car initially ran on the fuel in the fuel lines & carby (if it where a carby fed donk which I think the old 504 was) before the kero based fuel came into contact with the engines combustion chamber/s. When such an event happens the damage to the engine is nasty thru sever detonation problems causing failure of some moving parts within hence the 'dead stop'. The large cloud of smoke as you mention was the final explosion of the poor fuel/air mixture just prior to death of the 'Pug'.ugly things they where too.
The biggest diff between Avgas (petrol) & Avtur (Kero) is the liquids flash point not so much it's ability to mix. As most would know for an auto eng you need a much higher compression to support ignition using Diesel fuel where using petrol (Avgas) it can explode just looking at it!
Wmk2
A Piper Chieftain on an RPT run in the early 1980's was refuelled with Jet A-1 from drum stock, by the time the aircraft had backtracked for departure both engines were running rough and only just producing enough power to be able to taxi back to the terminal.