Turbines, safety and complacency
11-01-2016, 11:55 AM
#26
Since this thread was ended, American Airlines have had a near disaster with a 767 when a HP turbine let go on the takeoff roll. I was particularly interested in this occurrence as I was a 767 captain with the exact same engine, the CF 6 80 C2, a fadec engine. The HP turbine failure was uncontained (not the first time this has happened on a CF 6) and caused a serious fuel leak and fire in the right wing, which was burned out and collapsed.
What prevented this from becoming a disaster was that the right engine failed but the cross wind was from the left blowing the flame and smoke away from the fuselage allowing complete pax. evacuation without serious injury.
That was pure luck as it was with the SIA and Emirates 777 fires, imagine a left engine scenario.
WE can make our own luck by always facing the model into wind, so that any flame etc in a failed start blows clear of the model.
In thousands of starts on many brands of gas and kero start engines I have never noticed any start to be compromised by the headwind, BUT I have had a few wet / hot starts and the wind has always been my favour, just recently on my AMT Olympus ( never had one before on an AMT engine)
Those who do not consider wind direction important at startup and shutdown may care to reconsider in light of the AA experience ! Your choice.
David.
What prevented this from becoming a disaster was that the right engine failed but the cross wind was from the left blowing the flame and smoke away from the fuselage allowing complete pax. evacuation without serious injury.
That was pure luck as it was with the SIA and Emirates 777 fires, imagine a left engine scenario.
WE can make our own luck by always facing the model into wind, so that any flame etc in a failed start blows clear of the model.
In thousands of starts on many brands of gas and kero start engines I have never noticed any start to be compromised by the headwind, BUT I have had a few wet / hot starts and the wind has always been my favour, just recently on my AMT Olympus ( never had one before on an AMT engine)
Those who do not consider wind direction important at startup and shutdown may care to reconsider in light of the AA experience ! Your choice.
David.
Last edited by David Gladwin; 11-01-2016 at 11:57 AM.
11-01-2016, 04:12 PM
#27
Since this thread was ended, American Airlines have had a near disaster with a 767 when a HP turbine let go on the takeoff roll. I was particularly interested in this occurrence as I was a 767 captain with the exact same engine, the CF 6 80 C2, a fadec engine. The HP turbine failure was uncontained (not the first time this has happened on a CF 6) and caused a serious fuel leak and fire in the right wing, which was burned out and collapsed.What prevented this from becoming a disaster was that the right engine failed but the cross wind was from the left blowing the flame and smoke away from the fuselage allowing complete pax. evacuation without serious injury. That was pure luck as it was with the SIA and Emirates 777 fires, imagine a left engine scenario. WE can make our own luck by always facing the model into wind, so that any flame etc in a failed start blows clear of the model. In thousands of starts on many brands of gas and kero start engines I have never noticed any start to be compromised by the headwind, BUT I have had a few wet / hot starts and the wind has always been my favour, just recently on my AMT Olympus ( never had one before on an AMT engine) Those who do not consider wind direction important at startup and shutdown may care to reconsider in light of the AA experience ! Your choice. David.
11-04-2016, 03:03 AM
#29
Sorry, disagree with that ! During a start I believe one finger should always be on the transmitter throttle trim lever ( or whatever is being used to initiate start) so that in the event of ANY start malfunction, high or rapidly rising egt, (As seen on the GSU !) unusual noise etc, the first action should be to immediately set trim back which will immediately stop the pump, if running, and close the fuel valve, then close the manual valve and deal with any fire.
Its just the the same as starting a big CF6, ( 60,000 pounds of thrust) or any other fullsize engine, where a hand is kept on the fuel switch until, with a normal start sequence, the egt has stabilised and is falling towards normal idle egt.
David.
Its just the the same as starting a big CF6, ( 60,000 pounds of thrust) or any other fullsize engine, where a hand is kept on the fuel switch until, with a normal start sequence, the egt has stabilised and is falling towards normal idle egt.
David.
Last edited by David Gladwin; 11-04-2016 at 03:06 AM.
11-04-2016, 09:18 AM
#30
Sorry, disagree with that ! During a start I believe one finger should always be on the transmitter throttle trim lever ( or whatever is being used to initiate start) so that in the event of ANY start malfunction, high or rapidly rising egt, (As seen on the GSU !) unusual noise etc, the first action should be to immediately set trim back which will immediately stop the pump, if running, and close the fuel valve, then close the manual valve and deal with any fire.
Its just the the same as starting a big CF6, ( 60,000 pounds of thrust) or any other fullsize engine, where a hand is kept on the fuel switch until, with a normal start sequence, the egt has stabilised and is falling towards normal idle egt.
David.
Its just the the same as starting a big CF6, ( 60,000 pounds of thrust) or any other fullsize engine, where a hand is kept on the fuel switch until, with a normal start sequence, the egt has stabilised and is falling towards normal idle egt.
David.
Engine Starting Malfunctions
*1. Throttle (affected engine) - OFF
*2 Allow engine to continue cranking for 30 seconds minimum if starter still engaged. (The 60 second starter cycle limit can be exceeded for up to 30 seconds to achieve this)
*3. Engine & Fuel Master Switch (affected engine) - OFF
Last edited by franklin_m; 11-04-2016 at 10:59 AM.
11-04-2016, 12:18 PM
#31
I also have to disagree with leaving the transmitter on the ground if things start to go sideways on start up the first thing I am going to do is switch of the engine and usually the second thing will be to grab my blower.
11-04-2016, 03:30 PM
#32
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I would also like to recommend having a miniature extinguisher to hand as well as your large CO2 or (better still AFFF) extinguisher.
The problems with the big extinguisher are
1 It is heavy and cumbersome and generally people leave all the safety pins etc in place. All these things make it difficult to deploy quickly.
2 You know that once you use it it needs recharging - with associated cost and (more important) inconvenience.
I advise getting one of those devices that use a soda siphon bulb and are intended to inflate bicycle tyres.
They are quite effective for small tailpipe fires much quicker to deploy and after use - just change the bulb.
The problems with the big extinguisher are
1 It is heavy and cumbersome and generally people leave all the safety pins etc in place. All these things make it difficult to deploy quickly.
2 You know that once you use it it needs recharging - with associated cost and (more important) inconvenience.
I advise getting one of those devices that use a soda siphon bulb and are intended to inflate bicycle tyres.
They are quite effective for small tailpipe fires much quicker to deploy and after use - just change the bulb.
11-04-2016, 05:35 PM
#33
If you can windmill the engine; all we ever do for full scale tailpipe fire, wet start, or hot start; seems healthy blast of CO2 down the intake would do the trick. But the mini turbines don't have independent oil supplies to bearings, so shutting down fuel flow and wind-milling may not be an option.
11-05-2016, 09:42 AM
#35
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Our hangar fire suppression systems were AFFF based. Had a malfunction, flooded the hangar with foam to about 5 feet thick. Reclamation crews called out to give jets freshwater washdowns (among other things). I remember being told that AFFF was corrosive.
If you can windmill the engine; all we ever do for full scale tailpipe fire, wet start, or hot start; seems healthy blast of CO2 down the intake would do the trick. But the mini turbines don't have independent oil supplies to bearings, so shutting down fuel flow and wind-milling may not be an option.
If you can windmill the engine; all we ever do for full scale tailpipe fire, wet start, or hot start; seems healthy blast of CO2 down the intake would do the trick. But the mini turbines don't have independent oil supplies to bearings, so shutting down fuel flow and wind-milling may not be an option.
I didn't recommend squirting the AFFF down the intake. IN any case shutting off the fuel is usually enough for that.
btw Windmilling for the short times involved here won't do any damage the rpms are very low.
11-05-2016, 05:05 PM
#36
The AFFF is for the model or grass fires - the mini CO2 extinguisher is sufficient to put out the flame in the engine and can be deployed much more rapidly than any other type.
I didn't recommend squirting the AFFF down the intake. IN any case shutting off the fuel is usually enough for that.
btw Windmilling for the short times involved here won't do any damage the rpms are very low.
I didn't recommend squirting the AFFF down the intake. IN any case shutting off the fuel is usually enough for that.
btw Windmilling for the short times involved here won't do any damage the rpms are very low.
Copy all. It seems the simple answer would be to have the pilot on the transmitter, and a helper manning the CO2 extinguisher and positioned ready to blast it down the intake on pilot order.
05-23-2017, 05:25 AM
#37
Gentlemen,
I was going to leave this alone but I thought why? This is a smart topic to discuss so while I don't post often, I thought I should post this.
Our turbine engines have become incredibly reliable, we are very used to being able to simply fuel and fly without much concern. Unfortunately this has led to complacency with the operation of these engines.
At a recent event I noticed things have changed a great deal, much for the good, but some for the bad.
As mentioned our engines are reliable like crazy now days. They almost always do what we want them too. Sadly, what I witnessed (and finally said something about) is that during startup in particular a few critical aspects of the start up are being overlooked.
1. Extinguishers. I witnessed a number of starts where while extinguishers were present at the starting area, they were not within arms reach of the jet. In the case of a fire, particularly in the case of an engine seizure where fuel keeps flowing for a moment, we want to be able to get that fire out ASAP. Having to look around to where the extinguisher is, run to it, pull the pin and then use it takes precious time and could be the difference between a minor incident and a fireball.
2. Start zone safety, it always used to be a general rule that when you started a turbine you had nobody in the "blast zone", being in line with the turbine wheel or behind the jet. I witnessed a number of starts made with the tail pipe of the jet parallel to the runway, this left jet blast going into the pit area and the turbine wheel pointing directly towards the spectator area, now the spectator area was plenty far away from the start up area that even in the event of a catastrophic failure it is unlikely anything would reach the spectator area but when turned that direction it is very easy for somebody to be standing in closer proximity than they should be to the side of the airplane. On a less critical note for our safety but still an important consideration, at this field running the engine in that direction was also blowing up dirt from the ground and sending it back towards jets in the pit area.
The flight line at this event was also plenty far from the start area, and without thinking I made what I feel was a bad judgement call. I had started my bobcat multiple times with the tail pipe pointing towards the runway with pilots standing there. The P70 while blowing towards them, just didn't really have any affect, nobody seemed to notice and I didn't either. However, when I started my Olympus and ran it up to full power, the spotter that was on the flight line turned around and motioned that he was getting blasted. I didn't even think about it, it's all too easy to forget how far a jet blast on a big engine will be felt. I hopefully will never make that mistake again.
3. Monitoring during start up. Over the past few years I have seen a number of jets started with all the hatches on and the pilot just standing there and going through the start cycle. The engines are good, but they are far from perfect. Having your data terminal plugged in while start up is the safe and proper way to do things. It may allow you to catch a problem before a start up goes bad. When we had to start our engines with air, and use propane for start gas we never started anything without the data terminal plugged in. Once onboard starting gas and electric start were introduced we began getting lazy. Forgetful even. Again, I will admit to making a stupid mistake that fortunately nothing bad came out of it. Years ago I was having a great weekend flying my Kingcat with a G Booster 160+. The engine had been absolutely flawless and I started the airplane without removing the canopy, it started without fail and I flew an entire flight. Upon landing I couldn't find my data terminal, that's when I remembered I had plugged it on for shut down on my last flight and forgot to remove it from the jet before this flight. Fortunately it's flopping around inside the jet did not damage anything or cause me any issues but again, it taught me that no matter how good our engines are, there are many variables that could cause a huge problem, us being the big one!
4. The last thing I watched and realized afterwards that I too fell victim to is after start up, and everything running successfully, I would set my brakes and walk away from my jet to move extinguishers, data terminals etc. Transmitter sitting next to the jet or in my hand, it wouldn't really be all that hard to accidentally bump the throttle without realizing and those little wheels and brakes won't keep a jet at full throttle from hitting something.
I don't mean this thread to be a "the sky is falling" issue or anything like that. Safety amongst turbine modellers is very good and is part of the reason I am proud to be part of the turbine fraternity, but we all get complacent at some point it seems, maybe something very minor but if we remain vigilant in all starting procedures we minimize the risk of any real problems so lets take a minute to look back and ask ourselves, "do I really do everything according to the book and if I don't, I need to change that".
Despite turbine modellings safety record we are still sadly under the microscope by a lot of people, we don't want to "add fuel to the fire" for any reasons.
Just my opinion.
Jeremy
I was going to leave this alone but I thought why? This is a smart topic to discuss so while I don't post often, I thought I should post this.
Our turbine engines have become incredibly reliable, we are very used to being able to simply fuel and fly without much concern. Unfortunately this has led to complacency with the operation of these engines.
At a recent event I noticed things have changed a great deal, much for the good, but some for the bad.
As mentioned our engines are reliable like crazy now days. They almost always do what we want them too. Sadly, what I witnessed (and finally said something about) is that during startup in particular a few critical aspects of the start up are being overlooked.
1. Extinguishers. I witnessed a number of starts where while extinguishers were present at the starting area, they were not within arms reach of the jet. In the case of a fire, particularly in the case of an engine seizure where fuel keeps flowing for a moment, we want to be able to get that fire out ASAP. Having to look around to where the extinguisher is, run to it, pull the pin and then use it takes precious time and could be the difference between a minor incident and a fireball.
2. Start zone safety, it always used to be a general rule that when you started a turbine you had nobody in the "blast zone", being in line with the turbine wheel or behind the jet. I witnessed a number of starts made with the tail pipe of the jet parallel to the runway, this left jet blast going into the pit area and the turbine wheel pointing directly towards the spectator area, now the spectator area was plenty far away from the start up area that even in the event of a catastrophic failure it is unlikely anything would reach the spectator area but when turned that direction it is very easy for somebody to be standing in closer proximity than they should be to the side of the airplane. On a less critical note for our safety but still an important consideration, at this field running the engine in that direction was also blowing up dirt from the ground and sending it back towards jets in the pit area.
The flight line at this event was also plenty far from the start area, and without thinking I made what I feel was a bad judgement call. I had started my bobcat multiple times with the tail pipe pointing towards the runway with pilots standing there. The P70 while blowing towards them, just didn't really have any affect, nobody seemed to notice and I didn't either. However, when I started my Olympus and ran it up to full power, the spotter that was on the flight line turned around and motioned that he was getting blasted. I didn't even think about it, it's all too easy to forget how far a jet blast on a big engine will be felt. I hopefully will never make that mistake again.
3. Monitoring during start up. Over the past few years I have seen a number of jets started with all the hatches on and the pilot just standing there and going through the start cycle. The engines are good, but they are far from perfect. Having your data terminal plugged in while start up is the safe and proper way to do things. It may allow you to catch a problem before a start up goes bad. When we had to start our engines with air, and use propane for start gas we never started anything without the data terminal plugged in. Once onboard starting gas and electric start were introduced we began getting lazy. Forgetful even. Again, I will admit to making a stupid mistake that fortunately nothing bad came out of it. Years ago I was having a great weekend flying my Kingcat with a G Booster 160+. The engine had been absolutely flawless and I started the airplane without removing the canopy, it started without fail and I flew an entire flight. Upon landing I couldn't find my data terminal, that's when I remembered I had plugged it on for shut down on my last flight and forgot to remove it from the jet before this flight. Fortunately it's flopping around inside the jet did not damage anything or cause me any issues but again, it taught me that no matter how good our engines are, there are many variables that could cause a huge problem, us being the big one!
4. The last thing I watched and realized afterwards that I too fell victim to is after start up, and everything running successfully, I would set my brakes and walk away from my jet to move extinguishers, data terminals etc. Transmitter sitting next to the jet or in my hand, it wouldn't really be all that hard to accidentally bump the throttle without realizing and those little wheels and brakes won't keep a jet at full throttle from hitting something.
I don't mean this thread to be a "the sky is falling" issue or anything like that. Safety amongst turbine modellers is very good and is part of the reason I am proud to be part of the turbine fraternity, but we all get complacent at some point it seems, maybe something very minor but if we remain vigilant in all starting procedures we minimize the risk of any real problems so lets take a minute to look back and ask ourselves, "do I really do everything according to the book and if I don't, I need to change that".
Despite turbine modellings safety record we are still sadly under the microscope by a lot of people, we don't want to "add fuel to the fire" for any reasons.
Just my opinion.
Jeremy
Good thread, worth a bump...I'm curious, was this a Jet Event you noticed this, or was it a fun fly? Thanks Chris
05-23-2017, 07:52 AM
#38
IMO, in addition to having a fire ext handy, I recommend folks have a leaf blower.. it is far more effective at putting out engine start fires. and doesn't destroy the motor. Also don't use powder extinguishers.. use CO2 or Halon/Halotron.. Please don't bring a chemical one onto the flight line..
also
Remember for sanctioned events we are supposed to have water sprayer.. its the most effective at putting out a crash fire
A jet recently had a tailpipe fire at an event I was at.. someone grabbed an unfamiliar ext.. sprayed it.. it was powder.. it destroyed the engine and screwed up the plane.. They did it just as I was about to stick the leaf blower down the intake and blew it out, but they were a nanosecond quicker..
also
Remember for sanctioned events we are supposed to have water sprayer.. its the most effective at putting out a crash fire
A jet recently had a tailpipe fire at an event I was at.. someone grabbed an unfamiliar ext.. sprayed it.. it was powder.. it destroyed the engine and screwed up the plane.. They did it just as I was about to stick the leaf blower down the intake and blew it out, but they were a nanosecond quicker..
05-23-2017, 01:35 PM
#39
My Feedback: (28)
I use foam fire extinguishers. Small, compact and put out a large fire. I actually saw one yesterday while watching drag racing on tv put out a decent fuel fire on a top fuel drag car. I have 3 of them and they each do a pretty large area. Since they are nothing but soap and water they don't ruin anything, and actually put out fuel fires faster than co2.
https://www.walmart.com/ip/Fire-Gone...r-2pk/16203732
https://www.walmart.com/ip/Fire-Gone...r-2pk/16203732
