I suppose Airbus is going ahead with the electric taxi idea
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The departure holding point is a bit late to find out you have an engine problem during or after start
Who's going to tell me about a fuel leak after engine start though?
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"Who is monitoring your engine start? At a busy airport, the 7 aircraft behind you. They will be eating your smoke if you have a tailpipe fire."
USMCProbe, really? At night?
USMCProbe, really? At night?
Last edited by busav8r; 29th Jan 2013 at 17:29.
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"Most of us are taxiing out on one engine now, so how is this any different with regards to these points?"
My present company also tried to recommend and implement the one eng taxi out procedure but after several problems they quit the idea (thank god). Some of those problems could result in serious mechanical problems and maybe a safety concern.
Other than several fuel leaks during eng starts which most of them resulted in returning to the gate for troubleshooting, I once had what I would call a beginning of an eng fire due to a broken eng starter. At night and without any indication on the EWD, the problem was early detected by the ground technician after he spotted lots of smoke coming from the engine. Fortunately other than a broken starter no other damage resulted to the engine, but I wonder what would had happened if such problem had occurred while on the holding position...
So I wonder why there are people still adhering to these practice. But maybe that is just me...
My present company also tried to recommend and implement the one eng taxi out procedure but after several problems they quit the idea (thank god). Some of those problems could result in serious mechanical problems and maybe a safety concern.
Other than several fuel leaks during eng starts which most of them resulted in returning to the gate for troubleshooting, I once had what I would call a beginning of an eng fire due to a broken eng starter. At night and without any indication on the EWD, the problem was early detected by the ground technician after he spotted lots of smoke coming from the engine. Fortunately other than a broken starter no other damage resulted to the engine, but I wonder what would had happened if such problem had occurred while on the holding position...
So I wonder why there are people still adhering to these practice. But maybe that is just me...
Last edited by busav8r; 29th Jan 2013 at 19:48.
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In terms of cost I would think a few small cameras, don't have to be HD, would be just the ticket for monitoring start up. (Yes, I know, aviation standards!)
Don't know what a tug costs per push but if there is no airport mandate ("HAVE to have a tug") then I imagine the savings would really stack up over time.
I am a little surprised no one has arranged for wheels to be spun up for landing, but maybe the hit on the tires each landing isn't worth it, might be another saving there?
Just thinking out loud.
Don't know what a tug costs per push but if there is no airport mandate ("HAVE to have a tug") then I imagine the savings would really stack up over time.
I am a little surprised no one has arranged for wheels to be spun up for landing, but maybe the hit on the tires each landing isn't worth it, might be another saving there?
Just thinking out loud.
Monarch used to start the number 2 engine of their DC10 just prior to take off. After a couple of failures because it hadn't warmed up properly, they gave it up as a bad idea.
A lot of airlines already start engines with no ground crew present. So, in their case this concept rids them of 2 or 3 ground staff and the tug. Over time this will save them millions. Whether it will save them enough to offset the weight and additional maintenance costs of the drive unit remains to be seen.
Reversing off the gate is not new. Bae Jetstreams did it for years.
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Reversing off the gate is not new. Bae Jetstreams did it for years.
Posted from Pprune.org App for Android
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So I wonder why there are people still adhering to these practice. But maybe that is just me...
So I wonder why there are people still adhering to these practice. But maybe that is just me...
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A320F FCOM PRO-NOR-SOP-08 p1/6 :
...If, during the engine start, the ground crew reports a fuel leak from the engine drain mast, run the engine at idle for 5 min. If the leak disappears during these 5 min, the aircraft can be dispatched without maintenance action. If the leak is still present after 5 min, maintenance action may be required before the flight...
The statistics in my present company shows that in every 10,000 flights, about 2 airplanes need to return to the gate for troubleshooting due to this particular problem. The average delay caused by such problem is about 1 hour (due to maintenance).
Experience also shows that the problem may be solved if we try to shut down the eng and then perform a restart after that. But again, for that we need ground crew supervision.
In most cases those fuel leaks may be due:
- VBV gear motor particularly impacted by cold soak condition
- leak from shaft seals o-ring under cold soak condition
- HMU fluorocarbon seals do not provide an effective sealing at low temperature if the engine is not warm.
But I am not really surprised when I hear pilots saying that there's nothing wrong with the single eng taxi out... after all that's the actual industry tendency: try to save money at all costs.
For me, other than trying to save millions, this may represent a concerning attitude in terms of safety
...If, during the engine start, the ground crew reports a fuel leak from the engine drain mast, run the engine at idle for 5 min. If the leak disappears during these 5 min, the aircraft can be dispatched without maintenance action. If the leak is still present after 5 min, maintenance action may be required before the flight...
The statistics in my present company shows that in every 10,000 flights, about 2 airplanes need to return to the gate for troubleshooting due to this particular problem. The average delay caused by such problem is about 1 hour (due to maintenance).
Experience also shows that the problem may be solved if we try to shut down the eng and then perform a restart after that. But again, for that we need ground crew supervision.
In most cases those fuel leaks may be due:
- VBV gear motor particularly impacted by cold soak condition
- leak from shaft seals o-ring under cold soak condition
- HMU fluorocarbon seals do not provide an effective sealing at low temperature if the engine is not warm.
But I am not really surprised when I hear pilots saying that there's nothing wrong with the single eng taxi out... after all that's the actual industry tendency: try to save money at all costs.
For me, other than trying to save millions, this may represent a concerning attitude in terms of safety
Last edited by busav8r; 30th Jan 2013 at 10:45.
To avoid tipping on to the tail as one brakes down from reversing, a brake fitted to the nosewheel would automatically discontinue retardation as the wheel came off the ground.
You heard it here first and I shall defend my patent rights
You heard it here first and I shall defend my patent rights
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Basil,
I'm not 100% sure but I think that once you put the idea out in the open before patenting it , it becomes public information and can no longer be patented.
So no millions$ for you I'm afraid.
I'm not 100% sure but I think that once you put the idea out in the open before patenting it , it becomes public information and can no longer be patented.
So no millions$ for you I'm afraid.
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If you are flying out of busy airports and your taxi time is 15-45+ minutes these will save enormous amounts of fuel, especially on 737 and A320 sized and smaller aircraft that fly a lot of legs. Great idea.
Bear Behind
There's also a certain amount of anticipating legislation related to NOx emissions and noise here as well. Since airport communities are pressuring governments over local air quality (I know - there's more gas coming out of the bus that takes you to the airport...) and engine noise, this seems to be a reasonable solution. More especially so if, in the longer term, you can do away with the APU and use a hydrogen fuel cell in its place. Back of a fag packet calcs show the fuel saving on a taxi out at CDG or AMS vs. the penalty of flying around the dead weight on a 500nm sector to be well worth it.
Only provided it doesn't spontaneously combust... 
Given the potential pitfalls of electric taxi I'd rather Boeing be the first to deliver such a system
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I suppose Airbus is going ahead with the electric taxi idea
Ok got off my butt and googled it Luftansa technic and L-3 have only performed ground test's to see if the system will work, that is a long way off from making it happen. They are not the only players there is another system being developed for the a320. What I found...
DLR Airbus A320 Taxis on Electric Nose Wheel: #evworld
VIDEO: L-3 and Lufthansa get moving with e-taxi demonstrator
Just a thought, but could the Cabin Crew not be used to "Observe" on engine startup for any abnormal smoke/flames etc... on engine start up? Just a simple addition to procedures to have one standing by with a view of the back of the engines Flight Crew makes some kind of announcement "Cabin Crew standby for engine start", a crew member walks to a position where they can see the engines through the windows with another crew member upfront positioned with access to the intercom who can relay any signals from the observing CC a second call "Engine start complete" from the Flight Crew allows CC to resume normal duties.
Obviously for wide body aircraft one down each aisle perhaps required?
Obviously for wide body aircraft one down each aisle perhaps required?
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Some airlines single engine tax in and out every flight by SOP. Every time they start or shut down the second engine, there is no ground crew to monitor. NONE.
I started flying jets in the military that had to be manually started. I had quite a few hung starts, hot starts, no ignition, etc. In 1800 hours I had probably 15 or 20 abnormal starts.
Flying for airlines the last 17 years and 10k hours, I have had one abnormal start (no ignition), and it was maintained to less than optimum standards in SE Asia.
This includes 727,37, 57, 67, 77, and 320 series.
I will take my chances with starting with no ground crew. I see it as minimal risk.
I started flying jets in the military that had to be manually started. I had quite a few hung starts, hot starts, no ignition, etc. In 1800 hours I had probably 15 or 20 abnormal starts.
Flying for airlines the last 17 years and 10k hours, I have had one abnormal start (no ignition), and it was maintained to less than optimum standards in SE Asia.
This includes 727,37, 57, 67, 77, and 320 series.
I will take my chances with starting with no ground crew. I see it as minimal risk.
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USMCProbe, first of all sorry for my english, as it is not my first language (not even the second language), but I will try to do my best.
Apparently we have both the same military and civilian background, except the fact that I have been flying Airbuses for the last +12,000 hrs.
After reading your last post, I can't agree with you. My standards in aviation since day one has been SAFETY in first place. ALWAYS. I don't give a **** if my management tries to push me to fly with less fuel of what I think it is reasonable for safety reasons (wx, traffic delays, etc) or tries to convince me to save fuel doing single engine taxi outs as a regular practice or even tries to persuade me with fuel saving bonus. And to be honest I never had a single problem with such attitude. And do you know why? Because I always try to use good common sense and I always comply with the SOPs. In this particular case with the Airbus SOPs.
For me there's no such thing as minimal risk or low risk or almost no risk, as long as the SOPs requires for a certain procedure or to follow a certain recommendation. Unless of course the Airbus SOPs are different in the other side of the world (which can be possible).
During the last 12,000 hrs I had some fuel leaks during engine starts. Some of them I was able to recover after some time delay (3 or 4 minutes running the engine at idle), some after shutting down the eng and then restart it and some I had to return to the gate for troubleshooting. One time I had to change the airplane. Like I said in a previous post, a few years back I also had a broken eng starter which made me abort the eng start not because I had any indication on EWD, but because I was timely advised by the ground personnel.
I also know a case which happened to a spanish carrier (Vueling or Click Air maybe ?) a few years back, when they had an engine fire during the 2nd engine start up (during push back). The crew were able to shutdown the engines and order for an emerg evac without too much trouble. The fire crew was right there and minimal damage resulted from the incident. Again thanks for the timely advisory from the ground crew and also the location of the incident, that company for sure saved thousands of $$$.
For me does not make any sense and it can be considered a bad or even an unsafe attitude to disregard what is written in the SOPs, even tough the chances to happen something is considered to be minimal or residual. For some reason it is in the SOPs.
But like someone just said in a previous post, I don't see any problems to perform single engine taxi outs as long as I have a means to supervise the engine start ups. And I believe video cameras could be an excellent idea...
NOTE: For the CFM it is considered a fuel leak when the amount of drops of fuel exceeds a certain number. For instance, any leak below 60 drops per minute it is not considered a fuel leak and the acft can be dispatched without restrictions. But for instance if the fuel leak lies between 60 to 90 or even more drops per minute and depending on the origin of the problem (HMU, shaft seals o-ring, etc), some restrictions may apply (the aircraft may be allowed to fly for a few sectors). But in most cases troubleshooting is required.
Apparently we have both the same military and civilian background, except the fact that I have been flying Airbuses for the last +12,000 hrs.
After reading your last post, I can't agree with you. My standards in aviation since day one has been SAFETY in first place. ALWAYS. I don't give a **** if my management tries to push me to fly with less fuel of what I think it is reasonable for safety reasons (wx, traffic delays, etc) or tries to convince me to save fuel doing single engine taxi outs as a regular practice or even tries to persuade me with fuel saving bonus. And to be honest I never had a single problem with such attitude. And do you know why? Because I always try to use good common sense and I always comply with the SOPs. In this particular case with the Airbus SOPs.
For me there's no such thing as minimal risk or low risk or almost no risk, as long as the SOPs requires for a certain procedure or to follow a certain recommendation. Unless of course the Airbus SOPs are different in the other side of the world (which can be possible).
During the last 12,000 hrs I had some fuel leaks during engine starts. Some of them I was able to recover after some time delay (3 or 4 minutes running the engine at idle), some after shutting down the eng and then restart it and some I had to return to the gate for troubleshooting. One time I had to change the airplane. Like I said in a previous post, a few years back I also had a broken eng starter which made me abort the eng start not because I had any indication on EWD, but because I was timely advised by the ground personnel.
I also know a case which happened to a spanish carrier (Vueling or Click Air maybe ?) a few years back, when they had an engine fire during the 2nd engine start up (during push back). The crew were able to shutdown the engines and order for an emerg evac without too much trouble. The fire crew was right there and minimal damage resulted from the incident. Again thanks for the timely advisory from the ground crew and also the location of the incident, that company for sure saved thousands of $$$.
For me does not make any sense and it can be considered a bad or even an unsafe attitude to disregard what is written in the SOPs, even tough the chances to happen something is considered to be minimal or residual. For some reason it is in the SOPs.
But like someone just said in a previous post, I don't see any problems to perform single engine taxi outs as long as I have a means to supervise the engine start ups. And I believe video cameras could be an excellent idea...
NOTE: For the CFM it is considered a fuel leak when the amount of drops of fuel exceeds a certain number. For instance, any leak below 60 drops per minute it is not considered a fuel leak and the acft can be dispatched without restrictions. But for instance if the fuel leak lies between 60 to 90 or even more drops per minute and depending on the origin of the problem (HMU, shaft seals o-ring, etc), some restrictions may apply (the aircraft may be allowed to fly for a few sectors). But in most cases troubleshooting is required.
Last edited by busav8r; 31st Jan 2013 at 18:38.