Reduced Versus Full Takeoff Thrust
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Galaxy -
I've done my share of engine overhauls and hot sections...I'll bet you $100 you can't find one guy on Earth who's going to prove that reduced thrust departures (for two minutes) is gong to save more in engine overhaul costs then say 5000 hours of running at max cruise thrust at altitude.
I might also add that more time on the runway, gives the plane more of a chance to pick up FOD...food for thought considering the Concord was over gross...she might have missed that chunk of metal if she had been lighter...
I've done my share of engine overhauls and hot sections...I'll bet you $100 you can't find one guy on Earth who's going to prove that reduced thrust departures (for two minutes) is gong to save more in engine overhaul costs then say 5000 hours of running at max cruise thrust at altitude.
I might also add that more time on the runway, gives the plane more of a chance to pick up FOD...food for thought considering the Concord was over gross...she might have missed that chunk of metal if she had been lighter...
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So SSG reincarnation number 10 has finally admitted.....
But his problem is with management?
Time for his future rants to be in the Airlines, Airports and Routes forum
Mutt
I won't argue that power reduction can save overhaul costs
Time for his future rants to be in the Airlines, Airports and Routes forum
Mutt
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Mutt...there is no question that the sum total of your aviation repertoire would fall flat in a person to person debate with me. It would be a slaughter.
Do I argue that pulling back the power to 50% all day long would extend engine life...no...nor would sweeping the runway prior to all departures, or flying only in land, never near the ocean, staying away from the desert, or ice, that could crack off the inlets and dent a blade...or also keeping the 200 hour pilots you hire off the throttles so as not to overspeed inadvertently...we could also start doing oil changes after every flight...
And in the end, it's some mechanic, probably the same guy that missed the jack screw at Alaska Airlines that is checking the blades...
All right Mutt...do you get it? Do you actually fly planes to understand what I am talking about?
So there you are lined up on the runway, pulling it off as far down the runway as possible on some misguided mission to save the company money, when in fact there are a hundred other ways to do so that won't compromise safety one iota.
Seriously Mutt, just shut up..your just too stupid to talk.
Do I argue that pulling back the power to 50% all day long would extend engine life...no...nor would sweeping the runway prior to all departures, or flying only in land, never near the ocean, staying away from the desert, or ice, that could crack off the inlets and dent a blade...or also keeping the 200 hour pilots you hire off the throttles so as not to overspeed inadvertently...we could also start doing oil changes after every flight...
And in the end, it's some mechanic, probably the same guy that missed the jack screw at Alaska Airlines that is checking the blades...
All right Mutt...do you get it? Do you actually fly planes to understand what I am talking about?
So there you are lined up on the runway, pulling it off as far down the runway as possible on some misguided mission to save the company money, when in fact there are a hundred other ways to do so that won't compromise safety one iota.
Seriously Mutt, just shut up..your just too stupid to talk.
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Mutt...there is no question that the sum total of your aviation repertoire would fall flat in a person to person debate with me. It would be a slaughter.
Worked out that rotor rotation thingy yet? 
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person to person debate with me
Mutt
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@ TakeTheHighRoad.
If you looked at any metallurgical paper such as DoITPoMS - TLP Library Creep Deformation of Metals - Effects of stress and temperature, you'd see that the creep rate of a turbine blade will have an exponential dependence on temperature.
It pays to run the engines as cool as possible with any power setting greater than MCT.
If you looked at any metallurgical paper such as DoITPoMS - TLP Library Creep Deformation of Metals - Effects of stress and temperature, you'd see that the creep rate of a turbine blade will have an exponential dependence on temperature.
It pays to run the engines as cool as possible with any power setting greater than MCT.
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So true to form, once you are exposed as having no technical knowledge of large aircraft performance or operations, you immediately turn to insults.... usually resulting in a forum ban........
I wonder who you will come back as next time
Mutt
I wonder who you will come back as next time
Mutt
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TakeTheHighRoad aka SSG, take a hike tosser, mutt is a highly accomplished aviator, along with many others you take exception to - galaxy flyer, con-pilot etc. You have proven time and time again under your many guises that you know absolutely zip when it comes to aviation, and have absolutely nothing substantive to contribute to discussions.
Figured out that rotor direction thingy yet?
Figured out that rotor direction thingy yet?
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Well at the end of the day the real justification is that you guys do what your told...it just makes you guys feel better when pulling the gear up over the fence that you have 'just cause'.
It's the same mentality of a guy that sits down and eats three cheesecakes, obviously overweight...tells everyone he's got a thyroid problem.
It's the same mentality of a guy that sits down and eats three cheesecakes, obviously overweight...tells everyone he's got a thyroid problem.
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Problem? Who has a problem?
I think it's just fine that you run rated thrust on every takeoff, because that's more spare parts revenue for my employer (from whom I've retired, but I still collect dividends from). That's easy money for us.
Just don't think that attitude will find traction in an industry that survives or perishes on its avoidable costs.
I think it's just fine that you run rated thrust on every takeoff, because that's more spare parts revenue for my employer (from whom I've retired, but I still collect dividends from). That's easy money for us.
Just don't think that attitude will find traction in an industry that survives or perishes on its avoidable costs.
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barit1,
You had me worried for a moment, until I did a re-read of your tounge in cheek remark, which, to me, ends this whole discussion. If an engine manufacturer just loves full thrust takeoffs in the name of increased revenue for them from spare parts sales, that says it all
Doubters should take a good look at an Engine stress Vs Engine life graph which pretty much says it all, reduce the thrust (if possible), and increase the engine life and likelyhood of Engine failure DRAMATICALLY. I don't have the facility to post diagrams, but will have it done by a fellow prooner (my son). That one diagram is worth a thousand words.
TakeTheHighRoad, SSG, and all of your other mutant offspring, It seems that you have taken issue with one of the regular contributors here, who is part of the back-bone of PPRune. May I refer you to a contributor who:-
(1) Has an incredibly long career as a Professional Pilot and Performance Engineer for a MAJOR airline,
(2) Has vast experience on small to VERY large aircraft in that, and other airlines,
(3) Receives Boeing and engine manufacturer data directly from them, and returns it if faulty, which these major manufacturers accept,
(4) Very gracefully accepts correction if he makes an extremely rare mistake,
(5) Is an absolute gentleman of unparalleled restraint when insulted by FOOLS. He obviously belongs to the school of thought that if an insult is given, but not accepted, the insult remains with the person initiating it.
I have learned a lot from his sharing his considerable experience.
He goes by the name of Mutt on these forums
On a personal take, most discussion regarding use of Flex/Reduced thrust centres on cost saving. It's a very valid and truthful point, but, even if it were not, I would (and do) use Flex/Reduced thrust for every Takeoff possible in the interests of safety, such safety enhancement emanating from very significantly reduced engine stress, thus leading to a very significantly reduced probability of engine failure
This was an otherwise good thread for all pilots. Unfortunately it has been soiled by you, TakeTheHighRoad, SSG, and all of your other mutant offspring. Do us all a favour and ... or, as my good colleague Jack Macdonald once observed to me many decades ago .. in respect of a court martial in which he was a material witness .. "He said 'Go away, or words to that effect, Sir". (I have to play with extreme even-handedness) - JT
Now, let the sane debate continue.........
Best Regards,
Old Smokey (who does not share Mutt's degree of restraint.
You had me worried for a moment, until I did a re-read of your tounge in cheek remark, which, to me, ends this whole discussion. If an engine manufacturer just loves full thrust takeoffs in the name of increased revenue for them from spare parts sales, that says it all
Doubters should take a good look at an Engine stress Vs Engine life graph which pretty much says it all, reduce the thrust (if possible), and increase the engine life and likelyhood of Engine failure DRAMATICALLY. I don't have the facility to post diagrams, but will have it done by a fellow prooner (my son). That one diagram is worth a thousand words.
TakeTheHighRoad, SSG, and all of your other mutant offspring, It seems that you have taken issue with one of the regular contributors here, who is part of the back-bone of PPRune. May I refer you to a contributor who:-
(1) Has an incredibly long career as a Professional Pilot and Performance Engineer for a MAJOR airline,
(2) Has vast experience on small to VERY large aircraft in that, and other airlines,
(3) Receives Boeing and engine manufacturer data directly from them, and returns it if faulty, which these major manufacturers accept,
(4) Very gracefully accepts correction if he makes an extremely rare mistake,
(5) Is an absolute gentleman of unparalleled restraint when insulted by FOOLS. He obviously belongs to the school of thought that if an insult is given, but not accepted, the insult remains with the person initiating it.
I have learned a lot from his sharing his considerable experience.
He goes by the name of Mutt on these forums
On a personal take, most discussion regarding use of Flex/Reduced thrust centres on cost saving. It's a very valid and truthful point, but, even if it were not, I would (and do) use Flex/Reduced thrust for every Takeoff possible in the interests of safety, such safety enhancement emanating from very significantly reduced engine stress, thus leading to a very significantly reduced probability of engine failure
This was an otherwise good thread for all pilots. Unfortunately it has been soiled by you, TakeTheHighRoad, SSG, and all of your other mutant offspring. Do us all a favour and ... or, as my good colleague Jack Macdonald once observed to me many decades ago .. in respect of a court martial in which he was a material witness .. "He said 'Go away, or words to that effect, Sir". (I have to play with extreme even-handedness) - JT
Now, let the sane debate continue.........
Best Regards,
Old Smokey (who does not share Mutt's degree of restraint.
Last edited by Old Smokey; 11th Nov 2011 at 01:03. Reason: Small Correction
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Old Smokey:
Well, I didn't intend my post tongue-in-cheek - I was perfectly serious. It's only a few pfennigs in my pocket, but it somehow feels better when it's coming from hot jock like kt.
Well, I didn't intend my post tongue-in-cheek - I was perfectly serious. It's only a few pfennigs in my pocket, but it somehow feels better when it's coming from hot jock like kt.
Here it is....SSG V10. 
For one thing, GA engines are not designed for the use airline engines are, think of it, how mang GA engines will see 16,000 hours?
GF
For one thing, GA engines are not designed for the use airline engines are, think of it, how mang GA engines will see 16,000 hours?
GF
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Galaxy, I am all ears to how you and experts are going to demonstrate that an inner turbine wheel on a JT15D is some how manufactured to a lower standard then say your typical airline engine.
That's good to know though...the next time I do an engine overhaul I can now can call up Garret, Pratt, or Rolls and say...
'You know I heard on the internet that I can get a turbine wheel that will go 20000 cycles instead of the 5000 cycle one your trying to sell me'. and the response will be..
'Oh, yeah, that's the extra super duper turbine wheel that we only sell to the airlines, would you like one?
That's good to know though...the next time I do an engine overhaul I can now can call up Garret, Pratt, or Rolls and say...
'You know I heard on the internet that I can get a turbine wheel that will go 20000 cycles instead of the 5000 cycle one your trying to sell me'. and the response will be..
'Oh, yeah, that's the extra super duper turbine wheel that we only sell to the airlines, would you like one?
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how you and experts are going to demonstrate that an inner turbine wheel on a JT15D is some how manufactured to a lower standard then say your typical airline engine.
Formula One guys should buy their tyres at Harrys Cheap Tyres, they do the same job, both just bits of rubber on a wheel.
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Brian, we could speculate all day long that airline engines have more unobtanium in them then GA jet engines.
But I think those in the know here, are very well aware that the answer to this question lies in two turbine wheels made to spec...and one operator gets to do 'this' and another operator gets to do 'that'.
But I think those in the know here, are very well aware that the answer to this question lies in two turbine wheels made to spec...and one operator gets to do 'this' and another operator gets to do 'that'.
