Twin engined flights over long Oceanic routes
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Except that twins, even ETOPS twins are not required to climb away as safely as three and four engined planes. 4 engined plane with 1 engine out is required to climb at 3,0 % gradient. A 2 engined plane with 1 engine out is allowed to climb at only 2,4 %.
A340 did not need 4 engines. Engines were available to power MD11, which still is heavier than 340. Nor does A380 need 4 engines, because there are existing powerplants available to enable such a heavy aircraft to operate on three.
As statistically, you are more likely to get killed on the motorway to or from the airport (especially the way some foreign taxi drivers drive!), I don't worry about ETOPS. The chances from a problem there are far less.
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A little thought and respect please
Oddly, I find myself having to say this for the second time this week.
PPRuNe's USP, so to speak, is that it enables you to have your questions, (such as this one) answered by somebody who actually does the job. In this case, Bealzebub, a well respected PPRuNe member of long-standing and extensive flying experience on commercial jet aircraft. He has taken the time and trouble to provide two lengthy answers, the first of which might almost be described as definitive.
You are all free to ignore his comments or if you prefer, to disagree privately: However, to visit PPRuNe and argue the toss on matters technical with a technical expert whose job it is to do the very task in question is frankly, unwise, unless you have extensive experience flying large commercial jet aircraft. Imagine that the posted conversation was taking place without anonymity, in front of your friends, and consider whether your own position might become embarrassing?
Ultimately, there will be no incentive for other experts to respond in this forum if they are aware that their comments will simply be disregarded: It can be in none of ourr interests for this to happen.
PPRuNe's USP, so to speak, is that it enables you to have your questions, (such as this one) answered by somebody who actually does the job. In this case, Bealzebub, a well respected PPRuNe member of long-standing and extensive flying experience on commercial jet aircraft. He has taken the time and trouble to provide two lengthy answers, the first of which might almost be described as definitive.
You are all free to ignore his comments or if you prefer, to disagree privately: However, to visit PPRuNe and argue the toss on matters technical with a technical expert whose job it is to do the very task in question is frankly, unwise, unless you have extensive experience flying large commercial jet aircraft. Imagine that the posted conversation was taking place without anonymity, in front of your friends, and consider whether your own position might become embarrassing?
Ultimately, there will be no incentive for other experts to respond in this forum if they are aware that their comments will simply be disregarded: It can be in none of ourr interests for this to happen.
Bealzebub,
I may be wrong, but it seems to me that if you have an occurrence such as volcanic ash or fuel contamination, you are just as likely to be in the deep dodo with 4 engines as 2. Possibly more, since with ash, you have 4 to relight rather than two........Also, don't the records show that ETOPS has proved itself over the last 20 years to be as safe as 4 engines?
I'm not so sure about things like food poisoning and even just Montezuma's revenge caused by less than perfect on board hygiene - I have a feeling those are far more prevalent than engine failure. I may be wrong, but what do you think?
I may be wrong, but it seems to me that if you have an occurrence such as volcanic ash or fuel contamination, you are just as likely to be in the deep dodo with 4 engines as 2. Possibly more, since with ash, you have 4 to relight rather than two........Also, don't the records show that ETOPS has proved itself over the last 20 years to be as safe as 4 engines?
I'm not so sure about things like food poisoning and even just Montezuma's revenge caused by less than perfect on board hygiene - I have a feeling those are far more prevalent than engine failure. I may be wrong, but what do you think?
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Yes you are right.
It has to be said that such occurrences are also extremely unlikely, but nevertheless if the fuel is stopped from getting to the engines or runs out, it doesn't matter how many engines you have they will all stop. If you clog the engines with volcanic ash or flocks of birds etc. they may also stop.
ETOPS has had an extremely good safety record since its introduction and although there have been numerous infight engine shutdowns, there have never been 2 where the common cause was not something that that would have just as equally affected a 3 or 4 engine aircraft. The two examples that spring to mind are the Air Transat A330 that lost power due to fuel starvation, and the BA 747 that lost power due to volcanic ash ingestion. I recall there might have been a KLM 747 which had a similar occurence over Alaska some years back. However had the A330 in question had 4 engines or the 747 had 2, the causal result would have been the same.
Food poisioning whilst a consideration and there are procedures in place to prevent it affecting both pilots is certainly more common than engine failure. The loss of one engine during the ETOPS segment (without laying my hands on the statistics) is similar to the chances of winning the lottery jackpot. The loss of two engines would be like winning the lottery jackpot two weeks running. It is not theoretically impossible, but very unlikely. I suspect the joy of the experience would differ enormously as well !
It has to be said that such occurrences are also extremely unlikely, but nevertheless if the fuel is stopped from getting to the engines or runs out, it doesn't matter how many engines you have they will all stop. If you clog the engines with volcanic ash or flocks of birds etc. they may also stop.
ETOPS has had an extremely good safety record since its introduction and although there have been numerous infight engine shutdowns, there have never been 2 where the common cause was not something that that would have just as equally affected a 3 or 4 engine aircraft. The two examples that spring to mind are the Air Transat A330 that lost power due to fuel starvation, and the BA 747 that lost power due to volcanic ash ingestion. I recall there might have been a KLM 747 which had a similar occurence over Alaska some years back. However had the A330 in question had 4 engines or the 747 had 2, the causal result would have been the same.
Food poisioning whilst a consideration and there are procedures in place to prevent it affecting both pilots is certainly more common than engine failure. The loss of one engine during the ETOPS segment (without laying my hands on the statistics) is similar to the chances of winning the lottery jackpot. The loss of two engines would be like winning the lottery jackpot two weeks running. It is not theoretically impossible, but very unlikely. I suspect the joy of the experience would differ enormously as well !
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Bealzebub,
thanks for your well founded comments!
I agree that so far ETOPS have a very good safety record and that modern engine condition monitoring allows you to divert before the problem really affects flight safety. Quality manufacturing of jet engine components ( my area of expertise ) has definitely contributed to today's vastly improved engine reliability. Even more will come from current development programs.
Let's wait and see, why both RR powerplants on BA 38 refused to obey to the thrust increase command.
Frank
thanks for your well founded comments!
I agree that so far ETOPS have a very good safety record and that modern engine condition monitoring allows you to divert before the problem really affects flight safety. Quality manufacturing of jet engine components ( my area of expertise ) has definitely contributed to today's vastly improved engine reliability. Even more will come from current development programs.
Let's wait and see, why both RR powerplants on BA 38 refused to obey to the thrust increase command.
Frank
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Hola Bealzebub -
xxx
I do agree to some of your comments - In particular regarding the higher level of maintenance in today's airplanes and engines. But I am very concerned about the "bugs" you could still get with electronics and the automatic control they have over aircraft systems.
xxx
I value my flight engineers on the 747-200s... In the fuel starvation case of the Air Transat landing in Lajes, Azores, little was available as info to the crew except that the tank feeding an engine was getting empty at an abnormal rate. A flight engineer in a 747 would see a tank capacity gage going down at a fast rate, would never transfer fuel into that tank. And with 4 motors, who cares if that engine does flame-out by starvation. If remaining with 3 engines, we will just advise ATC, go some 4,000 feet lower, check that level's performance data, advise the company, and ask them if they want us to continue (or go back)... I am not criticizing the Air Transat crew, they did all their best (and a masterpiece of a glide demonstrating superior airmanship) - but as a training manager - I hate the modern concepts of "going to a check-list without much thoughts"... I sign the procedures revisions for the glass cockpit airplanes that we have, but I ask the fleet managers to feed-in their opinions. In my airline, I only know the planes we have from "last century", 747-200, 737-200, MD-80 and A-310s... For the 747-400 and A-340, I say "...su decisión, Che..." - your decisions...!
xxx
When we have a problem, we put 2 or 3 heads together in trying to undertand a source of problem, before jumping to today's concept of "what is the procedure" and blindly follow the "abnormals" of check-lists.
xxx
By chance we have 3 heads and 6 eyes (most often) in our A-310s and 747.400s. In our 747-400s, most of our "cruise co-pilots" are actually ex-F/Es from the 747-200, who continue F/E style duties for departure and arrival, and were trained to serve as F/O 747-400 in cruise. As much as I am against twins doing ETOPS, I fought for our "third guy", who are required, anyway, by the flight and duty time limitations we have.
xxx
Despite driving a 747 Classic, I sat down in ETOPS ground school and I have to agree I learned a lot. We apply much of what I learned in the 747s, in case of the loss of TWO engines, which then, requires to be landed ASAP on the nearest runway. We often cross the Amazon jungle/basin with 737 and MD-80s, and these guys need the education of getting to a safe landing somewhere. You dont want to feed the jaguars or the crocodiles of Brazil, anymore than the sharks between Europe and the Americas...
xxx
Old farts like me die hard. I recall the days of my DC-6 captains who had recently transitioned to 727 jets. in the late 1960s/early 1970s... You face the same wall with me with your "2 pilot crews" and "overwater twins"... Like some gentlemen SLF mentioned their preference for many engines for an overwater flight, I do same. When I am at times SLF myself, with other airlines and if my kids travel, I see them to be booked on 747s or MD-11s if they travel overwater.
xxx
Call it a phobia if you want to. I just name this "my aviation philosophy"... and I have others.
xxx
Happy contrails
xxx
I do agree to some of your comments - In particular regarding the higher level of maintenance in today's airplanes and engines. But I am very concerned about the "bugs" you could still get with electronics and the automatic control they have over aircraft systems.
xxx
I value my flight engineers on the 747-200s... In the fuel starvation case of the Air Transat landing in Lajes, Azores, little was available as info to the crew except that the tank feeding an engine was getting empty at an abnormal rate. A flight engineer in a 747 would see a tank capacity gage going down at a fast rate, would never transfer fuel into that tank. And with 4 motors, who cares if that engine does flame-out by starvation. If remaining with 3 engines, we will just advise ATC, go some 4,000 feet lower, check that level's performance data, advise the company, and ask them if they want us to continue (or go back)... I am not criticizing the Air Transat crew, they did all their best (and a masterpiece of a glide demonstrating superior airmanship) - but as a training manager - I hate the modern concepts of "going to a check-list without much thoughts"... I sign the procedures revisions for the glass cockpit airplanes that we have, but I ask the fleet managers to feed-in their opinions. In my airline, I only know the planes we have from "last century", 747-200, 737-200, MD-80 and A-310s... For the 747-400 and A-340, I say "...su decisión, Che..." - your decisions...!
xxx
When we have a problem, we put 2 or 3 heads together in trying to undertand a source of problem, before jumping to today's concept of "what is the procedure" and blindly follow the "abnormals" of check-lists.
xxx
By chance we have 3 heads and 6 eyes (most often) in our A-310s and 747.400s. In our 747-400s, most of our "cruise co-pilots" are actually ex-F/Es from the 747-200, who continue F/E style duties for departure and arrival, and were trained to serve as F/O 747-400 in cruise. As much as I am against twins doing ETOPS, I fought for our "third guy", who are required, anyway, by the flight and duty time limitations we have.
xxx
Despite driving a 747 Classic, I sat down in ETOPS ground school and I have to agree I learned a lot. We apply much of what I learned in the 747s, in case of the loss of TWO engines, which then, requires to be landed ASAP on the nearest runway. We often cross the Amazon jungle/basin with 737 and MD-80s, and these guys need the education of getting to a safe landing somewhere. You dont want to feed the jaguars or the crocodiles of Brazil, anymore than the sharks between Europe and the Americas...
xxx
Old farts like me die hard. I recall the days of my DC-6 captains who had recently transitioned to 727 jets. in the late 1960s/early 1970s... You face the same wall with me with your "2 pilot crews" and "overwater twins"... Like some gentlemen SLF mentioned their preference for many engines for an overwater flight, I do same. When I am at times SLF myself, with other airlines and if my kids travel, I see them to be booked on 747s or MD-11s if they travel overwater.
xxx
Call it a phobia if you want to. I just name this "my aviation philosophy"... and I have others.
xxx
Happy contrails
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Twin engined flights over long Oceanic routes
Thank you all for your comments and advice.
I did not realise that I had opened a subject that was so complex.
I thank Bealzebub for his obviously informed reply, the one definitive reply to my questions.
So it seems there is a wide opinion on the pro`s and cons of twin jet Oceanic flights.
Having studied the replys and opinions I think a four jet flight to the USA would serve my fears the best.
When do they make a six!?
Once again thank you all.
I did not realise that I had opened a subject that was so complex.
I thank Bealzebub for his obviously informed reply, the one definitive reply to my questions.
So it seems there is a wide opinion on the pro`s and cons of twin jet Oceanic flights.
Having studied the replys and opinions I think a four jet flight to the USA would serve my fears the best.
When do they make a six!?
Once again thank you all.
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When do they make a six!?
Latecoere 631 has 6 engines. As do many Convair B-36-s, including XC-99/Model 37. As does Boeing B-47. As well as Antonov An-225.
There are also planes with 8 engines. Like Hugher Hercules and Boeing B-52. There are planes with 10 engines. Like Saunders-Roe Princesses and many Convair B-36s - 6 turning, 4 burning. There is a plane with 12 engines, too - Dornier X.
I've done over 1 million miles on BA and over 1 million miles on AA in the last 29 years. A lot of those on ETOPS. I'm happy to continue on ETOPS flights.
The only thing to put me off is if the character in the right hand front seat isn't happy going, then neither am I!!!
Provided he doesn't want to srgue with me about the safety of using mobile 'phones. portable GPS etc. I don't argue with his professional ability, and I don't expect him to argue about mine. If he does, I don't trust his flying capabilities....
The only thing to put me off is if the character in the right hand front seat isn't happy going, then neither am I!!!
Provided he doesn't want to srgue with me about the safety of using mobile 'phones. portable GPS etc. I don't argue with his professional ability, and I don't expect him to argue about mine. If he does, I don't trust his flying capabilities....
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The only thing to put me off is if the character in the right hand front seat isn't happy going, then neither am I!!!
Provided he doesn't want to srgue with me about the safety of using mobile 'phones. portable GPS etc. I don't argue with his professional ability, and I don't expect him to argue about mine. If he does, I don't trust his flying capabilities....
How many times does the FO want to go if the LHS doesn't? I should have said LHS, not RHS....
There's another thread about mobile phones. There you find that professionals in the field of RF engineering, EMC, and avionics are disagreeing with pilots on the subject of the safety of using mobile 'phones. The professionals are saying 'No way, switch the **** off' while some pilots are saying 'We've never had a problem so there isn't one'.
There's a damn good reason for having the things switched off and anyone who doesn't like it, should, in my opinion, be ejected forthwith - no matter what altitude the aircraft is. Parachutes not optional.....
An interesting question Bealzebub, is why ATPL get tested every year and doctors and bus drivers and ambulance drivers (but paramedics do, I believe) etc don't.....and once an engineer qulaifies, he (or she) doesn't get retested...
There's another thread about mobile phones. There you find that professionals in the field of RF engineering, EMC, and avionics are disagreeing with pilots on the subject of the safety of using mobile 'phones. The professionals are saying 'No way, switch the **** off' while some pilots are saying 'We've never had a problem so there isn't one'.
There's a damn good reason for having the things switched off and anyone who doesn't like it, should, in my opinion, be ejected forthwith - no matter what altitude the aircraft is. Parachutes not optional.....
An interesting question Bealzebub, is why ATPL get tested every year and doctors and bus drivers and ambulance drivers (but paramedics do, I believe) etc don't.....and once an engineer qulaifies, he (or she) doesn't get retested...
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Twin engined flights over long Oceanic routes
Hi chornedsnorkack,
I was really refering to pax jets, incidently you missed out the Avro Shackleton MR3.3 (4 turning 2 burning) have flown in several (70`s)
I was really refering to pax jets, incidently you missed out the Avro Shackleton MR3.3 (4 turning 2 burning) have flown in several (70`s)
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I was really refering to pax jets, incidently you missed out the Avro Shackleton MR3.3 (4 turning 2 burning) have flown in several (70`s)
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Twin engined flights over long Oceanic routes
Hi contacttower,
The Shack MR3.3 had six, 4 griffons + 2 Vipers =6
The Vipers were used for takeoff supplementary to the Griffons and occasionally in the cruise.
The Vipers were mounted in the rear of the outboard Griffon nacelles, they got their air from below via retracting doors that were angled to scoop the airflow into the intake.
Takeoffs at high weight were long and noisy, ah but the smell of avgas, rubber and leather! Not to mention the chemical loo.
Nav by Loran and sextant.
The Shack MR3.3 had six, 4 griffons + 2 Vipers =6
The Vipers were used for takeoff supplementary to the Griffons and occasionally in the cruise.
The Vipers were mounted in the rear of the outboard Griffon nacelles, they got their air from below via retracting doors that were angled to scoop the airflow into the intake.
Takeoffs at high weight were long and noisy, ah but the smell of avgas, rubber and leather! Not to mention the chemical loo.
Nav by Loran and sextant.
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I had never give the matter much thought and I have crossed the pond more times than I can remember. I've been on the cushions on 747's twice, 777's more often than not and a solitary 767 and a lonesome 757 - all Seattle's finest craftsmanship with aero engines that Boeing have tried, tested and approved for use on said airframe before going into production!
If Boeing are happy, the British Airways Flight Crews and Continental Airlines Flight Crews (and any other airline's Flight Crews that might offer me a lift) are happy with two-engined machines flying across the world's oceans then so am I!
Usually, AFAIAW, the aircraft follow routes that don't take them too far from land anyway - after all, Boeing can deliver their ubiquitous short-range 737 aircraft anywhere worldwide through clever route planning and, for some useless information, a 737 takes off somewhere on the planet every 40 seconds on average!
If Boeing are happy, the British Airways Flight Crews and Continental Airlines Flight Crews (and any other airline's Flight Crews that might offer me a lift) are happy with two-engined machines flying across the world's oceans then so am I!
Usually, AFAIAW, the aircraft follow routes that don't take them too far from land anyway - after all, Boeing can deliver their ubiquitous short-range 737 aircraft anywhere worldwide through clever route planning and, for some useless information, a 737 takes off somewhere on the planet every 40 seconds on average!
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Very interesting thread- but just wondered if someone in the know could give me a rough answer to this question.
If you were to fly from say manchester to Vegas in a twin engined aircraft- what duration of that flight (10hours?) is actually over the water?
thanks
If you were to fly from say manchester to Vegas in a twin engined aircraft- what duration of that flight (10hours?) is actually over the water?
thanks
The rough answer would be approximately 50%. However, it's difficult to be more precise because it would be very much dependent on the track the aircraft took over the Atlantic.
For example, if it was assigned a relatively northerly track, you may find yourself flying over southern Greenland, reducing the proportion of your journey over water.
Also, bear in mind that some of the flight would be over Hudson Bay; over water yes, but not actually oceanic as such and always close to land.
Finally, remember that even when you are over the Atlantic, a lot of the time you are closer to a diversion airport than you realise; at various points in your journey Scotland, Northern Ireland, Iceland, Greenland and eastern Canada are no great distance away.
For example, if it was assigned a relatively northerly track, you may find yourself flying over southern Greenland, reducing the proportion of your journey over water.
Also, bear in mind that some of the flight would be over Hudson Bay; over water yes, but not actually oceanic as such and always close to land.
Finally, remember that even when you are over the Atlantic, a lot of the time you are closer to a diversion airport than you realise; at various points in your journey Scotland, Northern Ireland, Iceland, Greenland and eastern Canada are no great distance away.
