Both engines toasted
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FK,
There's no torque or temperature limiting on the PW 123 powerplants, so they can be overtorqued/temped. There's also a bit of lag in engine response (and torque) about mid-way through the power lever range which, if not anticipated can lead to a rapid (coarse) increase in torque. I suspect it's a characteristic of the fuel scheduling. It's not an issue in day-to-day operation, just something to be aware of
Some (not all) PW 121's exhibit similar characteristics.
There's no torque or temperature limiting on the PW 123 powerplants, so they can be overtorqued/temped. There's also a bit of lag in engine response (and torque) about mid-way through the power lever range which, if not anticipated can lead to a rapid (coarse) increase in torque. I suspect it's a characteristic of the fuel scheduling. It's not an issue in day-to-day operation, just something to be aware of
Some (not all) PW 121's exhibit similar characteristics.
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Yeah - but the PW123 has pretty good transient limits, you'd have to give it a serious wodge of power then sit there and pick your nose for a fair amount of time before you "toast" the engines.
Don Quixote Impersonator
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Aaah the old engine shut down and the engine winding down with the fuel pumps still blazing away trick.
Ground power relay? or the unit itself. I think you will get the T/prop manufacturers to admit they get more toasted engines from ground ops/ground power U/S/running out of fuel/dodgy relays and plugs just falling out at the "right time" than just about any other reason.
We spend a gazillion dollars servicing the aircraft but the last thing we seem to check is the ground power unit.
This is a real case of it ain't over till its over and the fat lady sings, and a trap for even the most wary.
Ground power relay? or the unit itself. I think you will get the T/prop manufacturers to admit they get more toasted engines from ground ops/ground power U/S/running out of fuel/dodgy relays and plugs just falling out at the "right time" than just about any other reason.
We spend a gazillion dollars servicing the aircraft but the last thing we seem to check is the ground power unit.
This is a real case of it ain't over till its over and the fat lady sings, and a trap for even the most wary.
Last edited by gaunty; 6th Sep 2006 at 07:30. Reason: afterthought. :)
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Air Nelson Dash 8 Two Engines Burning
Is it true that a Dash 8 burned out two engines on the ground in Palmerston North? How would you do that? Don't they have safety things to stop that? How dangerous was it for us the travelling public? How much will it cost?
loads i expect.
loads i expect.
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You've lost me there, c100driver
Perhaps if the condition levers were moved to "fuel off" then accidently back to "start/feather" while the donks are spooling down? Is that what you're implying?
Perhaps if the condition levers were moved to "fuel off" then accidently back to "start/feather" while the donks are spooling down? Is that what you're implying?
Last edited by Hugh Jarse; 7th Sep 2006 at 04:20. Reason: Clarification of my question
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Cl's were placed back at feather after shutdown, enough internal rotation to give fuel flow and ignition but with no air flow, i heard the props could not be rotated after second shutdown 
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I'd imagine NSN sending out an ops not "Thall shall not touch thy conditions levers after shutdown".
Bugger for the boys involved, hopefully those rugs don't have to be used to much
hanz
Bugger for the boys involved, hopefully those rugs don't have to be used to much
hanz
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Hugh, apparently so! Big billows of thick black smoke. From what I've heard, whoever was moving the condition levers to cutoff, thought they felt a bit strange, so decided to give them a few good 'full and free' checks. Doh!!! My guess is they won't do that again.
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Sexy time
Sorry if I hit a nerve.
There is nothing ignorant about my post. It is 100% correct from my part, that is what I've heard (this is a rumour network). If what I've heard is in fact incorrect, then please feel free to correct me. I don't have time for your personal attacks, try being objective, more people will listen to you.
Sorry if I hit a nerve.
There is nothing ignorant about my post. It is 100% correct from my part, that is what I've heard (this is a rumour network). If what I've heard is in fact incorrect, then please feel free to correct me. I don't have time for your personal attacks, try being objective, more people will listen to you.
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CC, it wasn't so much what you said, more like how you said it - like you were dining out on someone else's misfortune ("d'oh! My guess is they won't do that again"). Have to admit the first thing I thought when reading that was "Wow! What a guess, Einstein!" But I've been on this forum since it began in 1996 (despite my title claiming 1999) and you get to know who the plonkers are - and you aren't (usually) one of those.
Just remember, despite how good we think we are, this fact will never change: there but for the grace of God, go we.
BTW, hands up those who have been specifically trained NOT to move fuel levers out of cutoff when N1 (or the Q300 equivalent) is still above a specific amount...and using common sense does NOT count for the purposes of this question!
Cheers
Just remember, despite how good we think we are, this fact will never change: there but for the grace of God, go we.
BTW, hands up those who have been specifically trained NOT to move fuel levers out of cutoff when N1 (or the Q300 equivalent) is still above a specific amount...and using common sense does NOT count for the purposes of this question!
Cheers
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Hindsight makes us all experts. Introducing a brand new type can be fraught with danger, Other airlines within NZ and Auz have had some incidents much worse than this when introducing a new type.
This sort of incident can happen (very easily) to anyone who is relatively new to a type. Best not to be to critical it may be you one day.
This sort of incident can happen (very easily) to anyone who is relatively new to a type. Best not to be to critical it may be you one day.
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Deadhead,
It's common knowledge, not only for the dash, but for any turbine engine that once you select fuel off that you would never reselect it back to on for any known reason until the engine has stopped.
However, the typical engine shut-down sequence for the Dash 8 is that when the engines have been run (condition levers max), the condition levers are moved to start/feather for 30 seconds prior to selecting fuel off. There is a detent between each position (min, start/feather and fuel off), but it is VERY easy to pull the condition levers out over both the detents and accidently go directly to fuel off and miss start/feather altogether. It's also VERY easy to go "oops" and reselect start/feather in an effort to recover the situation, with potentially expensive results.
At the very least you get an impressive smokescreen good enough to turn out the firies, at worst you melt metal.
Lots have done it, and no doubt more will.
It's common knowledge, not only for the dash, but for any turbine engine that once you select fuel off that you would never reselect it back to on for any known reason until the engine has stopped.
However, the typical engine shut-down sequence for the Dash 8 is that when the engines have been run (condition levers max), the condition levers are moved to start/feather for 30 seconds prior to selecting fuel off. There is a detent between each position (min, start/feather and fuel off), but it is VERY easy to pull the condition levers out over both the detents and accidently go directly to fuel off and miss start/feather altogether. It's also VERY easy to go "oops" and reselect start/feather in an effort to recover the situation, with potentially expensive results.
At the very least you get an impressive smokescreen good enough to turn out the firies, at worst you melt metal.
Lots have done it, and no doubt more will.
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deadhead
Fair call, thanks for your candid response. I guess I was trying to make light of the situation, and went a bit far. Of course I feel sorry for the poor pilot who made the mistake, and yes, while in the comfort of my armchair I can say there are certain things I would and wouldn't do in an aircraft, I agree that we all make mistakes, and unfortunately sometimes this sort of thing will happen.
My apologies if I offended anyone.
*pulls head in*
Fair call, thanks for your candid response. I guess I was trying to make light of the situation, and went a bit far. Of course I feel sorry for the poor pilot who made the mistake, and yes, while in the comfort of my armchair I can say there are certain things I would and wouldn't do in an aircraft, I agree that we all make mistakes, and unfortunately sometimes this sort of thing will happen.
My apologies if I offended anyone.
*pulls head in*
Bottums Up
It's not unknown for turbines to not shutdown with the selection of fuel off due kinked cables, dud HP fuel valve, or whatever.
Though I've not had to do it, I have seen on more than one occasion, the fuel lever moved forward and then slammed home to shut the fuel off.
Though I've not had to do it, I have seen on more than one occasion, the fuel lever moved forward and then slammed home to shut the fuel off.
