VEE-TRANS 240 Mayday at Luton
Thank you so much to the ATC units involved yesterday in helping to deliver us safely on the ground!
I was First officer on this Chieftain, that suffered a catastrophic engine failure just as dawn was breaking over Luton. We were cruising at FL80 and it suddenly quit...In a violent way!
Luckily we were in VMC overhead the airfield, as we could not maintain altitude due to deformation of the cowling and loose parts of engine dangling in the slipstream!
I am so lucky! please get in touch if you were involved so that I can thank you personally!
Is there a possibility that the mags check wasn't completed during the run-up checklist ? I have heard of people performing run-ups on Navajos at a lesser RPM than that prescribed by the POH? Would that have helped to identify the mags issue and resulted in a return to the shop before taking off ?
Looks to me one or more cylinder bolts failed with the others following suit. The piston is fractured halfway through the pin presumably after getting out of alignment as the cylinder bolts gave way. Note the position of the piston at the bottom of the cylinder.
If the piston had broken while the cylinder was still fastened, it would likely have been left tucked up in the cylinder head.
RatherBeFlying wrote:Looks to me one or more cylinder bolts failed with the others following suit. The piston is fractured halfway through the pin presumably after getting out of alignment as the cylinder bolts gave way. Note the position of the piston at the bottom of the cylinder.
If the piston had broken while the cylinder was still fastened, it would likely have been left tucked up in the cylinder head.
We may be seeing an AD.
Perhaps. I thought of stud failure as well and it can be caused by something as simple as not putting oil on the threads during torque up (all torque values are lubricated) or using sealant to prevent leakage on the cylinder base.... which will migrate and take the pre-load off.
Strong leads indeed!
Anyone else surprised that the upper cowl could be peeled open in flight to that extent and not be instantly torn the rest of the way off?
J31 wrote:Hmmm no oil mess? Maybe a lack of oil in the engine?
Instantly seized allows no more oil movement ?
As the oil is all still contained in the pan, then dipstick oil-level would still be at the full mark as well.
It's feathered. Wouldn't that imply it was still turning fast enough to keep the locks out, till they got it feathered ? Been a long time since I flew the ho, but, memory tells me, it wont feather if it's already stopped.
goldeneagle is correct. If RPM drops below 800 - 900 RPM, start locks will engage, preventing the propeller from feathering.
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The average pilot, despite the somewhat swaggering exterior, is very much capable of such feelings as love, affection, intimacy and caring.
These feelings just don't involve anyone else.
Not necessarily. Locks usually only work at the fine pitch stops IIRC. If at coarse pitch, the blades would just go to feather when oil pressure was lost regardless of RPM.
YUP!! I should have hit the delete button rather than submit until I did some thinking about this and you are absolutley correct in this case.
I checked both a Flight Safety training manual and the AFM and they all say to feather the propeller before RPM drops below 1000 RPM.
I have to assume that they are thinking of an engine failure where power is reduced but the engine is still rotating in which case the prop would fine off, allowing the start locks to engage. From the picture, it would appear the engine possibly stopped rotating rather quickly and the loss of oil pressure due to the sudden stoppage would not allow time for the prop to fine off in which case the prop would go to feather.
It is important to bring this up because the same scenario can happen to almost any twin out there. Feather the prop before the prop can slow to 1000 RPM and fine off enough for the start locks to engage.
I also read where a Mu2 owned by the State of North Dakota and flown by a professional crew also had a sudden stoppage that tore the engine from its mounts and created so much drag, they were not able to make it to an airport.
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The average pilot, despite the somewhat swaggering exterior, is very much capable of such feelings as love, affection, intimacy and caring.
These feelings just don't involve anyone else.
If during the sudden stoppage the crankshaft broke there would be nothing to stop the blades from windmilling fast enough to feather normally.
It looks like the prop is a fairly heavy unit to suddenly stop on a dime ... so IMO the odds are the crank (just ahead of that first piston) would be the weakest link.
SOP in the oceanic flights on old radial in engine failure or prop runaway was to shut off the oil, windmill til it seized and watch the geardrive/prop depart. can't find a pic but similar to this viscount? failure.
I remember reading about prop failures with the Boeing 377 piston airliner and that is exacty what was preposed to combat an engine or prop failure in the middle of the Pacific Ocean enroute to Hawaii. By seizing the engine, a runaway prop would shear the crank, the prop would fall off and the flight would be out of imminent danger. In fact I was told that the engines on Boeing jets were designed to fall off and the fellow who told me that flew 707's for the RCAF. He claimed at one time it was not all that uncommon. I remember Boeing had problems with the fuses that held the engnes on a 747.
---------- ADS -----------
The average pilot, despite the somewhat swaggering exterior, is very much capable of such feelings as love, affection, intimacy and caring.
These feelings just don't involve anyone else.
Better a PETcock rather than a wild and untamed one.
---------- ADS -----------
The average pilot, despite the somewhat swaggering exterior, is very much capable of such feelings as love, affection, intimacy and caring.
These feelings just don't involve anyone else.
rigpiggy wrote:SOP in the oceanic flights on old radial in engine failure or prop runaway was to shut off the oil, windmill til it seized and watch the geardrive/prop depart. can't find a pic but similar to this viscount? failure.
I suspect you're thinking of stories of runaway props caused by loss of all the oil in an engine utilizing a prop control system requiring oil pressure to feather the prop. Lose all your oil and of course the oil pressure, the prop will go to course pitch and overspeed. Combination of overspeed and lack of lubrication is only going to end badly for the engine. If in fact the prop does depart when the engine seizes or gearbox fails, I’m sure it’s a bit of a crapshoot as to what it hits and how much damage it does on the way.
Anyways, not an SOP at all; everybody’s just along for the show as the overspeeding engine does what it’s going to do.
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Last edited by GyvAir on Mon Dec 02, 2013 6:45 pm, edited 1 time in total.
This isn't the first time I have heard of a jug departing….. I think it's the 3rd!!
