RB211s
A/T less
Straight from Handling The Big Jets. The Bible for the CX interview.
Advantages of the RB21 engine:
1. The engine is physically shorter because it has less compressor and turbine sections.
2. Because it is shorter it flexes less, is more rigid, and therefore gives better engine performance over the life of the engine.
3. The LP, IP, and HP sections all work closer to their optimum performance levels because they have their own shafts.
4. They have better fuel consumption, and lower noise.
5. Better thrust to weight ratio.
6. Easier to start because only one shaft has to be turned.
7. Modular in construction, easier to build and maintain.
8. Better propulsive efficiency
9. Since most of the fleet is powered by RR, it is cheaper for maintenance.
Hope this helps.
Straight from Handling The Big Jets. The Bible for the CX interview.
Advantages of the RB21 engine:
1. The engine is physically shorter because it has less compressor and turbine sections.
2. Because it is shorter it flexes less, is more rigid, and therefore gives better engine performance over the life of the engine.
3. The LP, IP, and HP sections all work closer to their optimum performance levels because they have their own shafts.
4. They have better fuel consumption, and lower noise.
5. Better thrust to weight ratio.
6. Easier to start because only one shaft has to be turned.
7. Modular in construction, easier to build and maintain.
8. Better propulsive efficiency
9. Since most of the fleet is powered by RR, it is cheaper for maintenance.
Hope this helps.
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B787
B787 - I am sure that we would all appreciate you posting the actual, verified numbers that would back your argument.
Whilst you are at it could you please show where the PW4056 engine comes by comparison to the RR and GE engine?
Could you give your information and include reference to actual numbers of engines manufactured, numbers fitted to B747 aircraft and hours flown per type of engine?
The pilots posting on this forum are usually hopeful recruits for either Cathay or Dragonair so it is important that they can go armed with facts rather than unsubstantiated opinion, don't you agree?
Whilst you are at it could you please show where the PW4056 engine comes by comparison to the RR and GE engine?
Could you give your information and include reference to actual numbers of engines manufactured, numbers fitted to B747 aircraft and hours flown per type of engine?
The pilots posting on this forum are usually hopeful recruits for either Cathay or Dragonair so it is important that they can go armed with facts rather than unsubstantiated opinion, don't you agree?
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There was a bit more involved in the choice of Roller, and from memory it goes back to the Tristar engine selection, I think it is mentioned in Beyond Lion Rock, or maybe another book wrt possible underhand dealing in relation the the initial engine choice, they have stuck with it till the A340, and they only deviated then because there wasnt a Roller offered for the -200/-300 buses. Have no experience with the GE, but from what I hear (my disclaimer) they are better in most respects when compared to the non GT RBs. CX now has the GT mod on all pax -400s and I imagine also on the Frtrs.
BE you off the decaf again?
BE you off the decaf again?
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here goes
General Electric CF6-80C2
Engine Overview
The CF6-80C2 high-bypass turbofan engine combines a proven core with the latest technical innovations to offer the highest reliability, longest life, and lowest fuel burn in its thrust class.
Technologies from a variety of research and development program have been incorporated in the CF6-80C2 design, such as advanced cooling techniques to improve overall efficiency, advanced clearance control, and aerodynamic modifications of blades and vanes. CF6 technology advances such as a new low emissions combustor and advanced high pressure turbine will maximize customer value well into the 21st century.
The CF6-80C2 entered revenue service in October 1985 and has consistently demonstrated the lowest specific fuel consumption of any commercial transport engine in its thrust class.
Currently certified on 11 widebody aircraft models and with 16 ratings, the CF6-80C2 has received FAA 180-minute Extended Twin-engine Operations (ETOPS) for the A300, A310, and B767 aircraft, offering route structuring flexibility and added economic benefits.
Physical Dimensions
Fan/Compressor Stages 1F/3LPC/14HPC
Low-Pressure Turbine/
High-Pressure Turbine Stages 5/2
Maximum Diameter (Inches) 106
Length (Inches) 168
Dry Weight (Lb.) 9,480
Application
Airbus A300-600/R/F
Airbus A310-200
A310-300
Boeing 767-200
767-200ER
767-300
767-300ER
767-400
767 AWACS
Japan E-767
747-300
747-400
MD-11
Power Specifications
Specific Fuel Consumption
at Maximum Power 0.307 - 0.344
Max. Power at Sea Level (Lb.) 52,500 - 63,500
Overall Pressure Ratio
at Maximum Power 27.1 - 31.8
Bypass Ratio 5 - 5.31
Pratt & Whitney PW4000 series
Physical Dimensions
Fan tip diameter: 94 inches
Length,flange to flange: 132.7 inches
Takeoff thrust: 52000 - 62000 pounds
Flat rated temperature: 86 or 92 degrees F
Bypass ratio: 4.8-to-1 to 5-to-1
Overall pressure ratio: 27.5 -32.3
Fan pressure ratio: 1.65-1.80
Rolls Royce Rb211-524
Technical details
The RB211-22B and -524 are three-shaft high-bypass-ratio engines; single-stage wide-chord fan; seven-stage IP compressor; six-stage HP compressor; single annular combustor with 18 fuel burners (24 on the G/H-T); single-stage HP turbine, single-stage IP turbine and a three-stage LP turbine.
Physical Dimensions
Fan/Compressor Stages 1F/7IPC/6HPC
Low-Pressure Turbine/
High-Pressure Turbine Stages 5/2
Maximum Diameter (Inches) 86.3
Length (Inches) 125
Dry Weight (Lb.) 9,600
Power Specifications
Specific Fuel Consumption
Cruise 0.563
Max. Power at Sea Level (Lb.) 50,000 - 63,000
Overall Pressure Ratio
at Maximum Power 27.1 - 31.8
Bypass Ratio 4.1-4.3
Mind you, Cathay love the RB211 so that's what I would be saying at an interview. All they want to know is that you think it is a lovely engine.
General Electric CF6-80C2
Engine Overview
The CF6-80C2 high-bypass turbofan engine combines a proven core with the latest technical innovations to offer the highest reliability, longest life, and lowest fuel burn in its thrust class.
Technologies from a variety of research and development program have been incorporated in the CF6-80C2 design, such as advanced cooling techniques to improve overall efficiency, advanced clearance control, and aerodynamic modifications of blades and vanes. CF6 technology advances such as a new low emissions combustor and advanced high pressure turbine will maximize customer value well into the 21st century.
The CF6-80C2 entered revenue service in October 1985 and has consistently demonstrated the lowest specific fuel consumption of any commercial transport engine in its thrust class.
Currently certified on 11 widebody aircraft models and with 16 ratings, the CF6-80C2 has received FAA 180-minute Extended Twin-engine Operations (ETOPS) for the A300, A310, and B767 aircraft, offering route structuring flexibility and added economic benefits.
Physical Dimensions
Fan/Compressor Stages 1F/3LPC/14HPC
Low-Pressure Turbine/
High-Pressure Turbine Stages 5/2
Maximum Diameter (Inches) 106
Length (Inches) 168
Dry Weight (Lb.) 9,480
Application
Airbus A300-600/R/F
Airbus A310-200
A310-300
Boeing 767-200
767-200ER
767-300
767-300ER
767-400
767 AWACS
Japan E-767
747-300
747-400
MD-11
Power Specifications
Specific Fuel Consumption
at Maximum Power 0.307 - 0.344
Max. Power at Sea Level (Lb.) 52,500 - 63,500
Overall Pressure Ratio
at Maximum Power 27.1 - 31.8
Bypass Ratio 5 - 5.31
Pratt & Whitney PW4000 series
Physical Dimensions
Fan tip diameter: 94 inches
Length,flange to flange: 132.7 inches
Takeoff thrust: 52000 - 62000 pounds
Flat rated temperature: 86 or 92 degrees F
Bypass ratio: 4.8-to-1 to 5-to-1
Overall pressure ratio: 27.5 -32.3
Fan pressure ratio: 1.65-1.80
Rolls Royce Rb211-524
Technical details
The RB211-22B and -524 are three-shaft high-bypass-ratio engines; single-stage wide-chord fan; seven-stage IP compressor; six-stage HP compressor; single annular combustor with 18 fuel burners (24 on the G/H-T); single-stage HP turbine, single-stage IP turbine and a three-stage LP turbine.
Physical Dimensions
Fan/Compressor Stages 1F/7IPC/6HPC
Low-Pressure Turbine/
High-Pressure Turbine Stages 5/2
Maximum Diameter (Inches) 86.3
Length (Inches) 125
Dry Weight (Lb.) 9,600
Power Specifications
Specific Fuel Consumption
Cruise 0.563
Max. Power at Sea Level (Lb.) 50,000 - 63,000
Overall Pressure Ratio
at Maximum Power 27.1 - 31.8
Bypass Ratio 4.1-4.3
Mind you, Cathay love the RB211 so that's what I would be saying at an interview. All they want to know is that you think it is a lovely engine.
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B787
Thanks for that B787.
jtr As mentioned above, the L1011 only came with the RR engine, any question of brown envelopes would only relate to the entire aircraft, Smith may be the name you are looking for.
Sorry, your remark re decaf not understood. As I am sure you will have noticed, the idea of this particular forum, apart from an opportunity for good natured thrust and parry and an exchange of ideas and humour, is to help the CX and Dragonair wannabes in their quest!
jtr As mentioned above, the L1011 only came with the RR engine, any question of brown envelopes would only relate to the entire aircraft, Smith may be the name you are looking for.
Sorry, your remark re decaf not understood. As I am sure you will have noticed, the idea of this particular forum, apart from an opportunity for good natured thrust and parry and an exchange of ideas and humour, is to help the CX and Dragonair wannabes in their quest!
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Yeh BE, now that I shake my cerebral mush a bit more your explanation sounds correct re Smith (or whoever it was) (long time since I read it, and cant remember where)
Re the decaf, just suggesting that you seemed to come out the gates with a twitchy trigger finger...
You said..
"B787 - I am sure that we would all appreciate you posting the actual, verified numbers that would back your argument.
Whilst you are at it could you please show where the PW4056 engine comes by comparison to the RR and GE engine?
Could you give your information and include reference to actual numbers of engines manufactured, numbers fitted to B747 aircraft and hours flown per type of engine?
The pilots posting on this forum are usually hopeful recruits for either Cathay or Dragonair so it is important that they can go armed with facts rather than unsubstantiated opinion, don't you agree?"
JMHO!
Good on him for taking the time to post the info! I would like to think the applicants are motivated enough to do their homework themselves. Google is an amazing thing, and with the clue given by 787, they could let their fingers do the walking. Of course now they may be in the difficult situation of trying to decide whether to blow rays up someones bhind, and tell them what a fantastic engine choice CPA made, or suggest that perhaps they would be better off with GEs or Pratts!
Re the decaf, just suggesting that you seemed to come out the gates with a twitchy trigger finger...
You said..
"B787 - I am sure that we would all appreciate you posting the actual, verified numbers that would back your argument.
Whilst you are at it could you please show where the PW4056 engine comes by comparison to the RR and GE engine?
Could you give your information and include reference to actual numbers of engines manufactured, numbers fitted to B747 aircraft and hours flown per type of engine?
The pilots posting on this forum are usually hopeful recruits for either Cathay or Dragonair so it is important that they can go armed with facts rather than unsubstantiated opinion, don't you agree?"
JMHO!
Good on him for taking the time to post the info! I would like to think the applicants are motivated enough to do their homework themselves. Google is an amazing thing, and with the clue given by 787, they could let their fingers do the walking. Of course now they may be in the difficult situation of trying to decide whether to blow rays up someones bhind, and tell them what a fantastic engine choice CPA made, or suggest that perhaps they would be better off with GEs or Pratts!
I used to fly for an airline with all three types of engine on their 747s. The general consensus amongst the pilots, engineers, management and accountants was in favour of the GE.
But when sitting in front of the Cathay Interviewers, I would say that the RR is definately the best!
But when sitting in front of the Cathay Interviewers, I would say that the RR is definately the best!
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BE
The 1011 did indeed only come with the RB211. Many would say that is why it was not as successful as it should have been.
There were quite a few Smiths around at the time. 'Bernie' E.B. Smith was the relevant one.
I may be wrong but heard one of the reasons (commonality aside) that CX stuck with the rollers on the 747's was the political clout it gave them in negotiating access to London, initially Gatwick and then Heathrow.
The 1011 did indeed only come with the RB211. Many would say that is why it was not as successful as it should have been.
There were quite a few Smiths around at the time. 'Bernie' E.B. Smith was the relevant one.
I may be wrong but heard one of the reasons (commonality aside) that CX stuck with the rollers on the 747's was the political clout it gave them in negotiating access to London, initially Gatwick and then Heathrow.
Last edited by Traffic; 5th Aug 2003 at 16:27.
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traffic
I think you may well have a point re the choice of RR engine, as well as the Swire Bros. natural leaning to the British engine.
I also suspect that beneath the surface there may well have been a none too insignificant can of political worms!
I also suspect that beneath the surface there may well have been a none too insignificant can of political worms!
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Those airlines that already have RB211 powered 744s are going to have to ride the future wave, but for those thinking of buying a 744 should stick to the GE.
The production version of the RB211 has been pushed to far. It's core is to small and therefore has the worse laps rate of the 3. She is fastest off the line but by 1000 ft she is lower and slower than the other 2.
Then there is the noise issue you all have been reading about and I have been dealing with for several years. Might just get them kicked out of several EU airports.
The production version of the RB211 has been pushed to far. It's core is to small and therefore has the worse laps rate of the 3. She is fastest off the line but by 1000 ft she is lower and slower than the other 2.
Then there is the noise issue you all have been reading about and I have been dealing with for several years. Might just get them kicked out of several EU airports.
RB211
Hi,
The only reason Cathay has picked RR is because the company was run by brits.....
Ok the RB211 burns less fuel than a CF6 but it is less reliable and much more heavier......not so good for a cargo A/C where payload is an issue.
Cheers:
PS: Give me a GE engine anytime....
The only reason Cathay has picked RR is because the company was run by brits.....
Ok the RB211 burns less fuel than a CF6 but it is less reliable and much more heavier......not so good for a cargo A/C where payload is an issue.
Cheers:
PS: Give me a GE engine anytime....
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My 2 cents worth: (like jtr, Beyond Lion Rock was a while ago)
In the 70's RR Aircraft Engines Division was on financially shakey ground..... in stepped Swire and saved their bacon by buying and promising to buy lots of RB211s...replacing the CX 707s with Tristars and RB211 powered 747s.
1. RR lives to fight anyother day.
2. British Govt happy as British jobs are saved at a time of record unemployment.
3. Swire & Cathay benefit in terms of routes etc to/from LHR/LGW and,
4. Mr Swire gets a Knighthood for services to industry. (poetic licence on my part....I have no idea if this contributed to his Knighthood....but I would say it was significant dont you think!)
Wannabes: RB211 is best for CX because of commonality (and therefore reduced maintenance costs!) the other points are also true BUT this is point No.1.
Of note is that CX is VERY interested in the 773ER.......I understand it only comes with a GE engine! So, times they maybe a changin'.
*I tried to go decaf....lasted 2 days! My daily piligrimage to Pacific Coffee is toooo much of a habit. (Or it may be all the little skirts at lunchtime?...Either way its an addiction!)
In the 70's RR Aircraft Engines Division was on financially shakey ground..... in stepped Swire and saved their bacon by buying and promising to buy lots of RB211s...replacing the CX 707s with Tristars and RB211 powered 747s.
1. RR lives to fight anyother day.
2. British Govt happy as British jobs are saved at a time of record unemployment.
3. Swire & Cathay benefit in terms of routes etc to/from LHR/LGW and,
4. Mr Swire gets a Knighthood for services to industry. (poetic licence on my part....I have no idea if this contributed to his Knighthood....but I would say it was significant dont you think!)
Wannabes: RB211 is best for CX because of commonality (and therefore reduced maintenance costs!) the other points are also true BUT this is point No.1.
Of note is that CX is VERY interested in the 773ER.......I understand it only comes with a GE engine! So, times they maybe a changin'.
*I tried to go decaf....lasted 2 days! My daily piligrimage to Pacific Coffee is toooo much of a habit. (Or it may be all the little skirts at lunchtime?...Either way its an addiction!)
Last edited by jungly; 26th Aug 2003 at 06:31.
