747-8 certification
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747-8 certification
As seen today in Flight:
Airbus is questioning why its rival Boeing should be allowed to grandfather" the certification of the new 747-8 on the back of the original version of the aircraft, which entered service in 1970.
And European regulators want Boeing to be required to undertake a full evacuation demonstration of the new 747 variant - something it avoided doing when the -400 was introduced in 1989.
Under previous 747 stretch development studies, such as the 747X of 2001, Boeing had intended to adopt an all-new certification path, but says it will pursue certification for the 747-8I/8F under an amended 747-400 type certificate.
The 747-400 was itself approved as an amendment to the certification of the original 747-100 that was launched in 1966
Boeing claims it's an all new A/C for the twenty first century, why then do they intend to save development costs by not submitting the B747-8 to the pax evacutation certification required for 2007? It's our safety that's at stake
Airbus is questioning why its rival Boeing should be allowed to grandfather" the certification of the new 747-8 on the back of the original version of the aircraft, which entered service in 1970.
And European regulators want Boeing to be required to undertake a full evacuation demonstration of the new 747 variant - something it avoided doing when the -400 was introduced in 1989.
Under previous 747 stretch development studies, such as the 747X of 2001, Boeing had intended to adopt an all-new certification path, but says it will pursue certification for the 747-8I/8F under an amended 747-400 type certificate.
The 747-400 was itself approved as an amendment to the certification of the original 747-100 that was launched in 1966
Boeing claims it's an all new A/C for the twenty first century, why then do they intend to save development costs by not submitting the B747-8 to the pax evacutation certification required for 2007? It's our safety that's at stake
Last edited by Thirty Eight South; 23rd Jan 2007 at 04:08. Reason: wrong marque - change to 747-8
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This Document may be interesting to read for those, who want to understand the philosophy behind "grandfathering". (may need an hour to read, and much longer to understand...)
We know, that the 747 airframe is a non damage tolerant structural design, we know that the 747 does not comply with today´s rules for rapid decompression, sustained engine imbalance, uncontained engine failure etc.
The problem will be to prove, that all the changes that need to be introduced to make the 747-8 comply with todays rules, will "contribute materially to the level of safety of the changed product". The 747-400 fleet service experience meets the safety goal of the rule, to make a catstrophic event (which can be linked to the aircraft design, so no CFIT etc.) an extremely remote one (less than one catastrophic event per 100.000.000 service hours).
It is not fair for shure, to make the A380 heavier than it would have to be to meet the 747 type certification standard, just because it has to comply with today´s rules. But following the rules for changes to certified products, the 747-8 may come away with the old rules. The wording is not very specific, the changes are not that significant (different engines, small fuselage plugs, different wingtips) to clearly make it a new type.
Who wants to blame Boeing to rate economy higher than safety, when indeed the operators and the passengers do the same? If two versions of the 747-8 would be available, one certified per the actual rules, and one "grandfathered", and the ticket prices would be 5% higher for the newer one, which would the passenger choose? I bet for the cheaper ticket.
I personally are absolutely unsatisfied with this situation, I always want a product to be as safe as it could be, and not as safe as it must be, but many people have a different philosophy.
I read a statement in some aviation paper a few years ago, when an airline manager complained about todays safety standards, to be to expensive. He stated, that customers obviously accepted 1970s aviation safety standards, because otherwise air traffic would not have grown from there, as it did. So there is no reason to increase safety requirements, if the customers are indeed happy with the existing ones. There is some logic behind that.
We know, that the 747 airframe is a non damage tolerant structural design, we know that the 747 does not comply with today´s rules for rapid decompression, sustained engine imbalance, uncontained engine failure etc.
The problem will be to prove, that all the changes that need to be introduced to make the 747-8 comply with todays rules, will "contribute materially to the level of safety of the changed product". The 747-400 fleet service experience meets the safety goal of the rule, to make a catstrophic event (which can be linked to the aircraft design, so no CFIT etc.) an extremely remote one (less than one catastrophic event per 100.000.000 service hours).
It is not fair for shure, to make the A380 heavier than it would have to be to meet the 747 type certification standard, just because it has to comply with today´s rules. But following the rules for changes to certified products, the 747-8 may come away with the old rules. The wording is not very specific, the changes are not that significant (different engines, small fuselage plugs, different wingtips) to clearly make it a new type.
Who wants to blame Boeing to rate economy higher than safety, when indeed the operators and the passengers do the same? If two versions of the 747-8 would be available, one certified per the actual rules, and one "grandfathered", and the ticket prices would be 5% higher for the newer one, which would the passenger choose? I bet for the cheaper ticket.
I personally are absolutely unsatisfied with this situation, I always want a product to be as safe as it could be, and not as safe as it must be, but many people have a different philosophy.
I read a statement in some aviation paper a few years ago, when an airline manager complained about todays safety standards, to be to expensive. He stated, that customers obviously accepted 1970s aviation safety standards, because otherwise air traffic would not have grown from there, as it did. So there is no reason to increase safety requirements, if the customers are indeed happy with the existing ones. There is some logic behind that.
monkeybdg, but the 747-8 is bigger that the -400, ie 5.6m longer. Significantly more pax to exit it by the same number and size of doors. That's why an evacuation test should be required.
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The Ford model T was very successful, so why make it any better? Operations have been done without anasthetic for hundreds of years so we obviously don't need it?
Statements like the managers words in Volumes post and those above are ridiculous. They stifle advancement and improvement. If only those managers could see how they are actually making things worse, then we might actually see real leaps and bounds in current aircraft operation. I'm not saying the 747-400 is a Ford model T, but taking these things to extremes often exposes how stupid they are. If 1970's safety standards were still in operation, we would have serious accidents every week and that wouldn't be palatable to any of us. Flap and gear controls the same size, position and shape anyone?
Statements like the managers words in Volumes post and those above are ridiculous. They stifle advancement and improvement. If only those managers could see how they are actually making things worse, then we might actually see real leaps and bounds in current aircraft operation. I'm not saying the 747-400 is a Ford model T, but taking these things to extremes often exposes how stupid they are. If 1970's safety standards were still in operation, we would have serious accidents every week and that wouldn't be palatable to any of us. Flap and gear controls the same size, position and shape anyone?
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groundloop..the difference between A318 and A321 or B737-600 and B737-800 is a lot bigger than 5.6 m .And I doubt they did a different pax evac test,or even certification.
Anyway,the A380 did a pax evac test for 800 pax,and flyies with only 550 ,maybe the 747 did the same.
How many seats are in a a jal 747,btw?
Anyway,the A380 did a pax evac test for 800 pax,and flyies with only 550 ,maybe the 747 did the same.
How many seats are in a a jal 747,btw?
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The issue is safety, and the purpose of certification is to avoid problems in new designs. The later does not ensure the former.
The 747 has been flying for 37 years with an enviable safety record. Its problems were identified, and fixed, long ago. Given a choice of an airplane with such a service history and a new design that jumped through a bunch of hoops, be it an A380 or a 787, I think only a bureaucrat would argue that the later is safer.
The 747 has been flying for 37 years with an enviable safety record. Its problems were identified, and fixed, long ago. Given a choice of an airplane with such a service history and a new design that jumped through a bunch of hoops, be it an A380 or a 787, I think only a bureaucrat would argue that the later is safer.
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The 747-400D (Domestic) is a high density seating model developed for short-haul domestic Japanese flights. Capable of seating 568 passengers, the aircraft is the highest-capacity passenger aircraft in the world, even when the Airbus A380 officially enters service.
As stated above, damage tolerance, rapid decompression, uncontained engine failure, emergency landing will require a complete redesign of the fuselage structure, if it should meet todays requirements. But most probably it will not meet performance requirements of the operators with the additional weight... So either the 747-8 will be "grandfathered" or cancelled.
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It makes no difference how much longer the airplane is (withing reason, IE: max 60 feet between exits, for example) but all has to do with the max capacity under original certification, with an equal number of exits.
Example.
Lockheed L1011, standard body aeroplane.
Max, 362, with six standard doors, and two smaller doors OR maximum 400 with eight standard doors.
B747 has 10 doors, except some with BA (as they apparently know better
)
Stretch the aeroplane.
Check the TCDS for the maximum capacity.
Add pax up to that maximum, with no additional evac demonstration required.
Done.
The Europeans?
They are just miffed because the white elephant (aka, A380) is overweight, overcost...and waaaay behind.
Ah, poor babies.
Example.
Lockheed L1011, standard body aeroplane.
Max, 362, with six standard doors, and two smaller doors OR maximum 400 with eight standard doors.
B747 has 10 doors, except some with BA (as they apparently know better
)Stretch the aeroplane.
Check the TCDS for the maximum capacity.
Add pax up to that maximum, with no additional evac demonstration required.
Done.
The Europeans?
They are just miffed because the white elephant (aka, A380) is overweight, overcost...and waaaay behind.
Ah, poor babies.
But the A321 has a completely different exit layout than the A318/19/20. Something Boeing managed to get away with it when they produced the 737-800 and -900. They could continue with 4 small overwing emergency exits because the 737 had "grandfather rights". Airbus, on the other hand, because the A320 came under newer rules required the different exit layout when certifying the 321.
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Usual kneejerk replies from the usual suspects.
If you actually bother reading the articles instead of trying to mudsling at the A380, it makes sense. There is much more than just evacuation numbers being discussed.
Items such as structures and doors come into it, which were certified in the 1960s and could do with revisiting. John Leahy made an important point as well concerning the forward maindeck cabin of the 747, which might not be acceptable using today's design criteria for emergency exits.
The 747-400 already benefitted from one compromise with the old CAA/British Airways dispute. That was one example of stretching the 1960s design approvals to cover a new variant. The 747-800 is even more distant from the original aircraft and only those with a vested interest can seriously argue against the policy of safety first.
Or are Boeing profits more important than people?
If you actually bother reading the articles instead of trying to mudsling at the A380, it makes sense. There is much more than just evacuation numbers being discussed.
Items such as structures and doors come into it, which were certified in the 1960s and could do with revisiting. John Leahy made an important point as well concerning the forward maindeck cabin of the 747, which might not be acceptable using today's design criteria for emergency exits.
The 747-400 already benefitted from one compromise with the old CAA/British Airways dispute. That was one example of stretching the 1960s design approvals to cover a new variant. The 747-800 is even more distant from the original aircraft and only those with a vested interest can seriously argue against the policy of safety first.
Or are Boeing profits more important than people?
Just another number
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411A
All of BA's 747-400s have 12 doors. Several years ago BA removed the overwing doors (with Boeing approval) on the 747-200s (no longer in service) when they reduced the passenger capacity, leaving 10 doors (8 main deck and 2 smaller upper deck doors).
Airclues
All of BA's 747-400s have 12 doors. Several years ago BA removed the overwing doors (with Boeing approval) on the 747-200s (no longer in service) when they reduced the passenger capacity, leaving 10 doors (8 main deck and 2 smaller upper deck doors).
Airclues
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Emotion doesn't enter into it.....It's Business
AB are in competition with Boeing, they are doing what any aggressive business does. They will take every opportunity to make life as difficult as possible for Boeing and naturally Boeing will reciprocate.
AB are in competition with Boeing, they are doing what any aggressive business does. They will take every opportunity to make life as difficult as possible for Boeing and naturally Boeing will reciprocate.
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groundloop..the difference between A318 and A321 or B737-600 and B737-800 is a lot bigger than 5.6 m .And I doubt they did a different pax evac test,or even certification.
Anyway,the A380 did a pax evac test for 800 pax,and flyies with only 550 ,maybe the 747 did the same.
How many seats are in a a jal 747,btw?
Anyway,the A380 did a pax evac test for 800 pax,and flyies with only 550 ,maybe the 747 did the same.
How many seats are in a a jal 747,btw?
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Hello all.
This will be more a political issue and a marketing stunt then anything else.
747's structure, especially -400 on which -8 is based is an overkill, for most of it. For modifications (i.e all the ADs and consequent SBs) DTA was performed, as required by regulatory documentation. So the complaints about fail-safe vs.. DT does not stand, or at least it is hard to support it.
EASA and FAA will come to the same ground because there are many other bigger and more important project looming on the certification horizon like 777F, A330-200F, A330 conversions (passenger to freighter), 787, A350.
For each and every of them a tit-for-tat game can be played and this helps nobody. For those of you who need explanation on the term overkill: loads used for initial (conceptual) design were far higher then the real loads coming from the fleet usage. Overall the issues mentioned related to structure (alleged lack of DT analysis) are not correct.
Cheers
This will be more a political issue and a marketing stunt then anything else.
747's structure, especially -400 on which -8 is based is an overkill, for most of it. For modifications (i.e all the ADs and consequent SBs) DTA was performed, as required by regulatory documentation. So the complaints about fail-safe vs.. DT does not stand, or at least it is hard to support it.
EASA and FAA will come to the same ground because there are many other bigger and more important project looming on the certification horizon like 777F, A330-200F, A330 conversions (passenger to freighter), 787, A350.
For each and every of them a tit-for-tat game can be played and this helps nobody. For those of you who need explanation on the term overkill: loads used for initial (conceptual) design were far higher then the real loads coming from the fleet usage. Overall the issues mentioned related to structure (alleged lack of DT analysis) are not correct.
Cheers
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[/quote]"The Europeans? They are just miffed because the white elephant (aka, A380) is overweight, overcost...and waaaay behind.
Ah, poor babies. [/quote]
-Maybe, but the point is that the B747-8 is an ICAO code F A/C for Airfield Rescue and Fire Fighting-a classification it uniquely has in common with the Airbus A380. Both of these A/C have to comply with this ICAO classification; it's not negotiable.
If I was an airport safety operator or authority I would be very interested to know that the passenger evacuation certification criteria are for any new large aircraft that is to begin operating into my airport, particaulary the certification issue; Airbus have a point, why does the rule apply to one airframer and suppossedly not the other?
And as for politics getting invovled - who started the WTO A350 v 787 wrangling?
Ah, poor babies.
[/quote]-Maybe, but the point is that the B747-8 is an ICAO code F A/C for Airfield Rescue and Fire Fighting-a classification it uniquely has in common with the Airbus A380. Both of these A/C have to comply with this ICAO classification; it's not negotiable.
If I was an airport safety operator or authority I would be very interested to know that the passenger evacuation certification criteria are for any new large aircraft that is to begin operating into my airport, particaulary the certification issue; Airbus have a point, why does the rule apply to one airframer and suppossedly not the other?
And as for politics getting invovled - who started the WTO A350 v 787 wrangling?
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Is it true that evacuation from 747 upper deck using the slides was never demonstrated by Boeing? I read somewhere they only evacuated passengers from upper deck using the stair to main deck and slides from there?
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As long as the cargo door lock design fault was rectified, that incident actually reassurred me with respect to the 747's hull strength and survivability.
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As long as the cargo door lock design fault was rectified, that incident actually reassurred me with respect to the 747's hull strength and survivability.
Further, can anyone advise on what extra hoops had to be jumped through for the A340-500 and -600 as opposed to the -200 and -300? Without checking the numbers, I'd think that a -600 is at least as much longer than a -200, than the 748 will be over a 744.
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If the 737-400 had been required to undergo a more comprehensive set of certification trials before carrying fare-paying passengers could the Kegworth accident, and several other 737-400 incidents around that time, have been avoided?
I know there were other contributory factors to the Kegworth accident, but the chain of events began with an issue that, it could be argued, should have been detected during the certification process had "grandfather" rights not been applied.
I know they changed the rules about engine certification, but have the other rules regarding "grandfather" rights altered since the Kegworth accident? If not, certain issues with the 747-8 might not be discovered until airline pilots and fare-paying passengers are on board, and one of the important lessons from the Kegworth accident will have been lost.
b.t.w. I've seen at first hand (fortunately in an environmental test facility) the effects that modifying a large structural component of an aircraft had on its resonant frequency and integrity. Our Client wanted us to significantly reduce the weight of the component, and this appeared to be feasible, however the weight reduction significantly altered the resonant frequency of the component. This resulted in all of the aircraft standard fasteners rapidly unwinding when the component was subjected to the expected vibration conditions. The fasteners unwound and the maintenance access panels fell open within seconds of the vibration test commencing. We tried beefier and beefier fasteners, but to no avail. It was amazing to see and surprised everyone except our chief mechanical engineer who was very experienced and had seen this sort of thing before. The solution to the problem was to offer less of a weight reduction, which resulted in a component that had a resonant frequency that was compatible with the rest of the airframe.
Porrohman.
I know there were other contributory factors to the Kegworth accident, but the chain of events began with an issue that, it could be argued, should have been detected during the certification process had "grandfather" rights not been applied.
I know they changed the rules about engine certification, but have the other rules regarding "grandfather" rights altered since the Kegworth accident? If not, certain issues with the 747-8 might not be discovered until airline pilots and fare-paying passengers are on board, and one of the important lessons from the Kegworth accident will have been lost.
b.t.w. I've seen at first hand (fortunately in an environmental test facility) the effects that modifying a large structural component of an aircraft had on its resonant frequency and integrity. Our Client wanted us to significantly reduce the weight of the component, and this appeared to be feasible, however the weight reduction significantly altered the resonant frequency of the component. This resulted in all of the aircraft standard fasteners rapidly unwinding when the component was subjected to the expected vibration conditions. The fasteners unwound and the maintenance access panels fell open within seconds of the vibration test commencing. We tried beefier and beefier fasteners, but to no avail. It was amazing to see and surprised everyone except our chief mechanical engineer who was very experienced and had seen this sort of thing before. The solution to the problem was to offer less of a weight reduction, which resulted in a component that had a resonant frequency that was compatible with the rest of the airframe.
Porrohman.
Last edited by Porrohman; 24th Jan 2007 at 16:40.