What Cost index are you using B737NG?
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We used 30, I found myself rarely adjusting the speeds for my own preference (Iworked for that Irish airline).
I did what needed to be done, for example If i knew the easyjet ten miles ahead was going to the same airport as us then I would overtake. This was not too difficult as those chaps often cruised at .76 and once .74!
I tried to beat the traffic at the end of the night which often worked and enabled ATC to give me us the fab shortcut which saved approximately 600 to almost 1000kgs!
So to answer fly the company CI and adjust your technique appropriately for the given circumstances.
De Facto - You have a brain - use it. You don't have to stick rigidly to SOP's, you are deliberatley reducing your choices unreasonably.
I did what needed to be done, for example If i knew the easyjet ten miles ahead was going to the same airport as us then I would overtake. This was not too difficult as those chaps often cruised at .76 and once .74!
I tried to beat the traffic at the end of the night which often worked and enabled ATC to give me us the fab shortcut which saved approximately 600 to almost 1000kgs!
So to answer fly the company CI and adjust your technique appropriately for the given circumstances.
De Facto - You have a brain - use it. You don't have to stick rigidly to SOP's, you are deliberatley reducing your choices unreasonably.
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EAGERBEAVEr1:
[QUOTE]De Facto - You have a brain - use it. You don't have to stick rigidly to SOP's, you are deliberatley reducing your choices unreasonably.""
May i ask you where in my statements did you get that i was rigidly following my sops?
Concerning my brain i do use it ,thank you very much,maybe you should read,assimilate then type
[QUOTE]De Facto - You have a brain - use it. You don't have to stick rigidly to SOP's, you are deliberatley reducing your choices unreasonably.""
May i ask you where in my statements did you get that i was rigidly following my sops?
Concerning my brain i do use it ,thank you very much,maybe you should read,assimilate then type
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Eagerbeaver1,
Insult is not a sign of intelligence especially for one who does not take time to read and whose perception is oviously wrong.
See even a muppet can do that:
Ryan air?huh? I see they trained you well,they will really miss your style
Now i suggest you adjust your attitude in your new position or your 'experienced captains' will swiftly put you back in place.
Another assumption/perception:oxford graduate before ryan air?
Insult is not a sign of intelligence especially for one who does not take time to read and whose perception is oviously wrong.
See even a muppet can do that:
Ryan air?huh? I see they trained you well,they will really miss your style
Now i suggest you adjust your attitude in your new position or your 'experienced captains' will swiftly put you back in place.
Another assumption/perception:oxford graduate before ryan air?
Last edited by de facto; 12th Oct 2011 at 05:07.
There are probably as many different opinions on this as there are Captains. The trick, IMO, is to base that opinion on a bit of knowledge rather than just inheriting an opinion off your first pilot group, or influential Captain etc.
The fact that we are discussing this and sharing info is a good start.
I think it comes down to a simple choice;
A) Shall I save an apparently small amount of fuel knowing that across the fleet, over the financial year, it will add a lot to the profitability of the company. or;
B) Shall I look after No.1 and who cares about the company they don't care about me, I want to get there quick.
A lot of pilots think that flying LRC will see them arriving overhead the field with the most gas in tanks. Thats a bit scary but true.
A lot of pilots don't know that ECON accounts for wind but LRC does not.
The more we can analyse the opinions of our peers with the mindset that we might learn something, the better.
My 2cents.
Framer
The fact that we are discussing this and sharing info is a good start.
I think it comes down to a simple choice;
A) Shall I save an apparently small amount of fuel knowing that across the fleet, over the financial year, it will add a lot to the profitability of the company. or;
B) Shall I look after No.1 and who cares about the company they don't care about me, I want to get there quick.
A lot of pilots think that flying LRC will see them arriving overhead the field with the most gas in tanks. Thats a bit scary but true.
A lot of pilots don't know that ECON accounts for wind but LRC does not.
The more we can analyse the opinions of our peers with the mindset that we might learn something, the better.
My 2cents.
Framer
It was a veiled attempt to stop you two from questioning each others intellect, abilities, and flying pedigree and return the thread to a more factual/technical tone.
After a quick think about it I think that
was the main thing I was trying to express.
analyse the opinions of our peers with the mindset that we might learn something, the better.
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interesting thread
Take the time to read all 4 pages of this thread and one might be forgiven for thinking that today's flight crews don't have a clue about things that they're supposed to be knowledgeable about.
And childishly keep bickering among themselves about it, too.
I won't comment on remarks with respect to each others perceived airmanship (apparently in short supply), let alone common employee decency (get paid- do the job as requested and to the best ability).
Do, however, feel free to continue to amuse the rest of us.
+++
Max Endurance equals Min Fuel Burn.
An aircraft will be able to stay aloft the longest at Min Drag Speed, not Best L/D.
Best L/D will get you the most bang for your fuel bucks in terms of range, not endurance. Two different things entirely.
Holding should be flown at Min Drag speed (clean wing!) for the specific conditions.
+++
It is said that MRC equals CI=0. This is not true, and a case of apples & pears.
ECON speeds derived from programming CI values into the FMS/FMC result from taking into consideration the impact of winds and temperatures on specific range, resulting in optimized, minimum COST speeds for the given and expected circumstances compared to the more coarse (corrected) fixed Mach flying.
LRC burns 1% more than MRC, but is similarly less efficient compared to flying at CI-managed ECON speeds, again, because of the actual atmosphere versus still air conditions.
Provided that CI values are correctly derived & set, cruising a fixed Mach regime will always COST more than CI-managed cruise. I've seen up to 15% more Specific Range efficiency at low levels and high headwinds.
CI-managed cruise makes you fly faster in a headwind, and fly slower with a tailwind. For those of you with gliding experience- sounds familiar?
Question is- who pays for that increased cost when ignorance decides that he or she knows better (often), or that the boffins don't have a clue (equally often), or simply shows a case of GetHomeItis (as stated in this thread)?
On the other hand, determining CI values is an art.
The simple version of CI calculation is focused on the cost of flying an additional minute; what Variable Time Cost do I incur compared to what increased Fuel Cost.
This is a coarse approximation, but since most airlines don't have a clue about Variable versus Fixed Costs of Time, or even how to accurately determine these costs, this becomes the preferred method, sometimes even using benchmark numbers found elsewhere in a (cost-wise) different operation.
(Variable) Cost of Time doesn't change often (contract negotiations, change of MRO), however, Cost of Fuel does.. on a weekly basis, even per city pair.
Compared to 12 months ago the average fuel price is 30% higher and so, consequently, your CI values should be about 30% lower than last year. Are they?
The more complex method takes into consideration the overall organic network effect of slowing down or speeding up the fleet (As CI values approach the lower 10s, schedules get stretched upwards to accommodate the slower flying, subsequently requiring additional flight crews to fill those higher block times, in turn creating additional network cost). City-pair specific fuel price deltas (sector-specific CI values) and additionally, specific aircraft operating limitations by only allowing a certain band of ECON speeds for climb, cruise and descent (we want to avoid having aircraft ECONning at such low speeds and high alphas that a stall comes close), and of course tail-specific performance degradation factors.
Lastly, ATC still doesn't get it after all these years, even though most everybody is cruising sloooooooowly nowadays.
Off-optimum levels, lousy vectoring, pushing speeds, bad sequencing, no clue about individual aircraft performance, all that jazz.
So What Is Wisdom?
Me thinks that the one who has the correct answer can sell a very nice tool.
Now, continue ze bickering, I find it amusing
Max
And childishly keep bickering among themselves about it, too.
I won't comment on remarks with respect to each others perceived airmanship (apparently in short supply), let alone common employee decency (get paid- do the job as requested and to the best ability).
Do, however, feel free to continue to amuse the rest of us.
+++
Max Endurance equals Min Fuel Burn.
An aircraft will be able to stay aloft the longest at Min Drag Speed, not Best L/D.
Best L/D will get you the most bang for your fuel bucks in terms of range, not endurance. Two different things entirely.
Holding should be flown at Min Drag speed (clean wing!) for the specific conditions.
+++
It is said that MRC equals CI=0. This is not true, and a case of apples & pears.
ECON speeds derived from programming CI values into the FMS/FMC result from taking into consideration the impact of winds and temperatures on specific range, resulting in optimized, minimum COST speeds for the given and expected circumstances compared to the more coarse (corrected) fixed Mach flying.
LRC burns 1% more than MRC, but is similarly less efficient compared to flying at CI-managed ECON speeds, again, because of the actual atmosphere versus still air conditions.
Provided that CI values are correctly derived & set, cruising a fixed Mach regime will always COST more than CI-managed cruise. I've seen up to 15% more Specific Range efficiency at low levels and high headwinds.
CI-managed cruise makes you fly faster in a headwind, and fly slower with a tailwind. For those of you with gliding experience- sounds familiar?
Question is- who pays for that increased cost when ignorance decides that he or she knows better (often), or that the boffins don't have a clue (equally often), or simply shows a case of GetHomeItis (as stated in this thread)?
On the other hand, determining CI values is an art.
The simple version of CI calculation is focused on the cost of flying an additional minute; what Variable Time Cost do I incur compared to what increased Fuel Cost.
This is a coarse approximation, but since most airlines don't have a clue about Variable versus Fixed Costs of Time, or even how to accurately determine these costs, this becomes the preferred method, sometimes even using benchmark numbers found elsewhere in a (cost-wise) different operation.
(Variable) Cost of Time doesn't change often (contract negotiations, change of MRO), however, Cost of Fuel does.. on a weekly basis, even per city pair.
Compared to 12 months ago the average fuel price is 30% higher and so, consequently, your CI values should be about 30% lower than last year. Are they?
The more complex method takes into consideration the overall organic network effect of slowing down or speeding up the fleet (As CI values approach the lower 10s, schedules get stretched upwards to accommodate the slower flying, subsequently requiring additional flight crews to fill those higher block times, in turn creating additional network cost). City-pair specific fuel price deltas (sector-specific CI values) and additionally, specific aircraft operating limitations by only allowing a certain band of ECON speeds for climb, cruise and descent (we want to avoid having aircraft ECONning at such low speeds and high alphas that a stall comes close), and of course tail-specific performance degradation factors.
Lastly, ATC still doesn't get it after all these years, even though most everybody is cruising sloooooooowly nowadays.
Off-optimum levels, lousy vectoring, pushing speeds, bad sequencing, no clue about individual aircraft performance, all that jazz.
So What Is Wisdom?
Me thinks that the one who has the correct answer can sell a very nice tool.
Now, continue ze bickering, I find it amusing
Max
