art
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A380 - Any Wash Separation Problems In Reality?

Tue Dec 11, 2007 5:56 pm

Now that the A380 is actually taking off and landing at airports every day, are there any reports regarding the anticipated wash problems?
 
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Stitch
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RE: A380 - Any Wash Separation Problems In Reality?

Tue Dec 11, 2007 5:57 pm

I don't recall anything untoward being reported. I believe she still operates under "special" considerations with slightly larger separations, but as more of them enter service and airports become more familiar with them, hopefully those considerations will be removed (and I hope the same for the 747-8).
 
ikramerica
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RE: A380 - Any Wash Separation Problems In Reality?

Tue Dec 11, 2007 6:01 pm



Quoting Stitch (Reply 1):
I believe she still operates under "special" considerations with slightly larger separations, but as more of them enter service and airports become more familiar with them, hopefully those considerations will be removed (and I hope the same for the 747-8).

That's what I expect. I know some people got all defensive about it, but frankly, for safety reasons, there's nothing wrong with doing it this way. There won't be a critical mass of A380s until 2009 at the earliest. The only airline it might impact at all would be SQ at that time, and if SQ wants to ignore the spacing, they can get the Singapore government to do so.
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Cubsrule
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RE: A380 - Any Wash Separation Problems In Reality?

Tue Dec 11, 2007 7:40 pm



Quoting Ikramerica (Reply 2):
The only airline it might impact at all would be SQ at that time, and if SQ wants to ignore the spacing, they can get the Singapore government to do so.

Also, it's not like either SYD or SIN is so horribly congested that a little extra spacing makes a big difference. When there are all kinds of 380s at LHR (and 380s comprise a larger portion of SQ's fleet), that will obviously change.
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futurecaptain
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RE: A380 - Any Wash Separation Problems In Reality?

Tue Dec 11, 2007 7:53 pm



Quoting Art (Thread starter):
are there any reports regarding the anticipated wash problems?

Well, those second level windows are hard to wash as is the huge tail area. Of course, AF won't care about wash problems.  Smile

Now, the wake on the other hand...
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OldAeroGuy
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RE: A380 - Any Wash Separation Problems In Reality?

Tue Dec 11, 2007 10:39 pm



Quoting Stitch (Reply 1):
I believe she still operates under "special" considerations with slightly larger separations, but as more of them enter service and airports become more familiar with them, hopefully those considerations will be removed (and I hope the same for the 747-8).

Wake separation requirements are a function of the physical characteristics of the airplane in question. No amount of operational familiarity will serve to reduce separation standards.

Until Airbus can provide data taken under controlled flight test conditions to the regulatory authorities (EASA, FAA and Eurocontrol) that shows the A380 wake is no greater than the 742/3/4, the current additional 1 nm separation between the A380 and other types in trail will remain in place. So far, Airbus has been unable to provide such a data set although they have done a substantial amount of additional testing.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
ikramerica
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RE: A380 - Any Wash Separation Problems In Reality?

Tue Dec 11, 2007 10:50 pm



Quoting OldAeroGuy (Reply 5):
Wake separation requirements are a function of the physical characteristics of the airplane in question. No amount of operational familiarity will serve to reduce separation standards.

Standards are always adjusted (up and down) in all fields based on in practical experience. Initial testing can only tell you so much, and regulations based on initial tests should always be conservative to prevent disaster. Regulations can be relaxed over time.
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OldAeroGuy
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RE: A380 - Any Wash Separation Problems In Reality?

Tue Dec 11, 2007 11:12 pm



Quoting Ikramerica (Reply 6):
Standards are always adjusted (up and down) in all fields based on in practical experience. Initial testing can only tell you so much, and regulations based on initial tests should always be conservative to prevent disaster.

Not always true. Second segment climb requirements have not changed since the initial issue of FAR Part 25 nor have structural load factor requirements.

This is one of those areas where catastrophic results cannot be tolerated. It's not in the same category as relaxed structural inspections due to no observed damage during the original inspection interval.

What would be the basis for a change in separation requirements? If no incidents/accidents occur with the current separation standards, do you propose a continual reduction is separation until an incident/accident does occur?
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
threepoint
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RE: A380 - Any Wash Separation Problems In Reality?

Tue Dec 11, 2007 11:21 pm



Quoting Ikramerica (Reply 6):
Regulations can be relaxed over time.

Could you please share with me an example of where an aviation safety regulation has been 'relaxed over time', particularly after such a limited amount of in-service experience for the airplane type in question? I find it odd that some have claimed Airbus has devoted substantial flight testing with the hope of reducing separation-in-trail distances (which would of course be to their benefit) but yet your last post states that 'initial testing can only tell you so much". I wonder, which is it?

Until it is proven that the risks associated with following an A380 are no greater than those of a 747, you can expect the standards will remain as they are today.
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zeke
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RE: A380 - Any Wash Separation Problems In Reality?

Tue Dec 11, 2007 11:40 pm



Quoting Art (Thread starter):
Now that the A380 is actually taking off and landing at airports every day, are there any reports regarding the anticipated wash problems?

In Toulouse they have been operating the A380 in the circuit with many different aircraft types, large and small, and for the most part been treating it just like any other big jet with no reported problems.

Quoting OldAeroGuy (Reply 5):
Wake separation requirements are a function of the physical characteristics of the airplane in question. No amount of operational familiarity will serve to reduce separation standards.

It was "operational familiarity" not "physical characteristics" that lead to the FAA reducing the wake separation distances in the past.

At the moment many from the US are trying to rewrite history and put glass ceilings on what is and is not allowed for certification of new types, we saw many unnecessary impediments put in the place of the A380, and with the 787 and 748 we see many things being swept under the carpet.

Quoting OldAeroGuy (Reply 5):
Until Airbus can provide data taken under controlled flight test conditions to the regulatory authorities (EASA, FAA and Eurocontrol) that shows the A380 wake is no greater than the 742/3/4, the current additional 1 nm separation between the A380 and other types in trail will remain in place. So far, Airbus has been unable to provide such a data set although they have done a substantial amount of additional testing.

Airbus has sent, or is about to send another lot of data off.

Airbus does not need to show "A380 wake is no greater than the 742/3/4", that is a false statement. The wake an aircraft generates is somewhat irrelevant, it is how that wake effects following aircraft that is relevant.

It is somewhat false to think that ONLY "physical characteristics" determine the wake of an aircraft, it is physics of the aircraft passing through the fluid, not the "physical characteristics". Through smart design of the airframe they can change the outcome. We see that all the time with aircraft design, the simplest example is the vortex generator seen on many engine nacelles.

They were expecting standard heavy separation as a result of the latest set of tests, everything so far as been interim recommendations only.
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WingedMigrator
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RE: A380 - Any Wash Separation Problems In Reality

Tue Dec 11, 2007 11:51 pm



Quoting OldAeroGuy (Reply 5):
Wake separation requirements are a function of the physical characteristics of the airplane in question.

You are making the incorrect assumption that the standards are rigorously based on physics.

Quoting OldAeroGuy (Reply 5):
No amount of operational familiarity will serve to reduce separation standards.

The temporary standards for the A380 have already been relaxed at least once:

http://www.icao.int/icao/en/ro/apac/2007/FIT_SEA5/ip05.pdf

Paragraph 3 of this ICAO document states:

Quote:
It is anticipated that the group will undertake additional studies with a view to further refinement of this guidance on the basis of operational experience

(emphasis added). Since these additional studies have yet to be completed, to my knowledge, it is possible that further relaxation will be made in the A380 wake separation standards.
 
OldAeroGuy
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 12:00 am

Quoting Zeke (Reply 9):
It is somewhat false to think that ONLY "physical characteristics" determine the wake of an aircraft, it is physics of the aircraft passing through the fluid, not the "physical characteristics". Through smart design of the airframe they can change the outcome. We see that all the time with aircraft design, the simplest example is the vortex generator seen on many engine nacelles.

Pardon me, but aren't the physical characteristics of the airplane what determines the physics of the wake? Geometry of the airframe is certainly a physical characteristic as is airplane weight. Besides airplane weight and geometry, what other unique airplane characteristics determines the physics of the wake?

Quoting Zeke (Reply 9):
It was "operational familiarity" not "physical characteristics" that lead to the FAA reducing the wake separation distances in the past.

No, 747 testing outside of actual operations played a major part in the current separation standards. The physical characteristics either stayed the same or increased in the case of weight. Can you provide a reference where operational experience reduced separation distances for airplanes in trail to the 747?

Quoting Zeke (Reply 9):
Airbus has sent, or is about to send another lot of data off.

And the results of these data will be of great interest. However, they still are not the result of operational experience.

[Edited 2007-12-11 16:05:23]
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
Mir
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 12:09 am



Quoting Threepoint (Reply 8):
Could you please share with me an example of where an aviation safety regulation has been 'relaxed over time',

ETOPS. Started out as 120 minutes, then 138 got added on, then 180, then 207, and now we're looking at 330. Back when it first came out, if you had told people that an airplane could reliably fly 207 on one engine, they would have thought you were crazy. But it's been proven that it can be done, have the standards have gotten less restrictive with regard to what twins can do.

If the 380 proves that it can match the wake turbulence characteristics of a 747, then the separation can go down to the normal heavy separation.

-Mir
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OldAeroGuy
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 12:38 am



Quoting Mir (Reply 12):
Quoting Threepoint (Reply 8):
Could you please share with me an example of where an aviation safety regulation has been 'relaxed over time',

ETOPS. Started out as 120 minutes, then 138 got added on, then 180, then 207, and now we're looking at 330.

Yes, the ETOPS diversion times have changed, but not because of a relaxation of standards. Increased diversion time is granted only through improvements to engine reliability and airplane system capability.

Engine reliability for 180 min ETOPS must be better than the standard required for 120 min ETOPS. Likewise, having cargo fire protection of 120 min won't allow you to fly 180 min.

Quoting WingedMigrator (Reply 10):
Quoting OldAeroGuy (Reply 5):
Wake separation requirements are a function of the physical characteristics of the airplane in question.

You are making the incorrect assumption that the standards are rigorously based on physics.

No, I'm not assuming there is a rigorous application. However, the difference in separation between a 747 in trail to a 747 and a 737 in trail to a 747 is based on the physical characteristics of both airplane.

Quoting WingedMigrator (Reply 10):
Quoting OldAeroGuy (Reply 5):
No amount of operational familiarity will serve to reduce separation standards.

The temporary standards for the A380 have already been relaxed at least once:

http://www.icao.int/icao/en/ro/apac/...5.pdf

Yes, but as your reference states, this change was based on the data from the flight test program, not operational experience. See page 2 paragraph 2 of the document (part of the cover letter).

Quoting WingedMigrator (Reply 10):
Paragraph 3 of this ICAO document states:

Quote:
It is anticipated that the group will undertake additional studies with a view to further refinement of this guidance on the basis of operational experience

(emphasis added). Since these additional studies have yet to be completed, to my knowledge, it is possible that further relaxation will be made in the A380 wake separation standards.

It will be interesting to see if there is a concrete proposal for actual inservice operational studies or if this refers to the data Zeke quotes.

Quoting Zeke (Reply 9):
Airbus has sent, or is about to send another lot of data off. ..................

They were expecting standard heavy separation as a result of the latest set of tests, everything so far as been interim recommendations only.

Again, these are not inservice operational data, but a new set of Airbus flight test data.
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TheSonntag
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 12:55 am



Quoting OldAeroGuy (Reply 13):
Engine reliability for 180 min ETOPS must be better than the standard required for 120 min ETOPS. Likewise, having cargo fire protection of 120 min won't allow you to fly 180 min.

Yes, but the fact that Etops 180 exists is a revolution itself. No doubt that there must be special provisions in place, but with 1960s technology, nobody would have thought about Etops 180 at all, that was unthinkable at that time.
 
threepoint
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 1:05 am



Quoting Mir (Reply 12):
ETOPS. Started out as 120 minutes, then 138 got added on, then 180, then 207, and now we're looking at 330.

I would argue that the standards haven't relaxed at all, they are progressively newer standards based upon new requirements. There are successive hurdles an aircraft must surpass in order to be permitted to fly further distances (as measured by time) from suitable aerodromes. Your logic would indicate that an aircraft originally certified for ETOPS 120 means it can now fly ETOPS 207 without further modification.
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Mir
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 1:16 am



Quoting Threepoint (Reply 15):
I would argue that the standards haven't relaxed at all, they are progressively newer standards based upon new requirements.

The standards used to be "no twin engine airplanes beyond 60 minutes of a suitable airport". Those standards then got relaxed, with certain provisions. Then they got more relaxed, with more provisions.

If Airbus can demonstrate that a 380's wake is no different from that of a 747, then the separation will go down. Call it new standards based on demonstrated capabilities if you like, call it a relaxation of standards if you like, but it comes to the same thing.

-Mir
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zeke
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 1:31 am



Quoting OldAeroGuy (Reply 11):
Pardon me, but aren't the physical characteristics of the airplane what determines the physics of the wake? Geometry of the airframe is certainly a physical characteristic as is airplane weight.

Nope, it is how the lift is generated.

The simplest example of how you are incorrect is by comparing a 744 landing at the same mass at flap 20 and landing at full flap, they generate different wake turbulence signatures despite having the same physical characteristics. The high lift devices play a major role in the generation of the wake turbulence.

Quoting OldAeroGuy (Reply 11):
Besides airplane weight and geometry, what other unique airplane characteristics determines the physics of the wake?

Even Boeing have acknowledged that the A380 has a better wing than even the 748i.

Airbus put a lot of work into the wing design, it has unique leading edge devices, and almost full span high lift devices, a large wing fence, high bypass engines, and a modern airfoil section, all of which influence the high lift characteristics of the aircraft, and subsequently the wake generation.

Quoting OldAeroGuy (Reply 11):
Can you provide a reference where operational experience reduced separation distances for airplanes in trail to the 747?

Good presentation on the development of the current standards http://wwwe.onecert.fr/projets/WakeN...retigny-november/James_Hallock.pdf

I dont think you are aware of a number of the steps given your posts.

Quoting OldAeroGuy (Reply 11):
And the results of these data will be of great interest. However, they still are not the result of operational experience.

Any data that is produced from flight testing is "operational" experience, you have made the leap to assume it only means commercial activities.

Quoting OldAeroGuy (Reply 13):
Yes, but as your reference states, this change was based on the data from the flight test program, not operational experience. See page 2 paragraph 2 of the document (part of the cover letter).

Where does it say COMMERCIAL operational experience ?

Quoting Threepoint (Reply 8):
Could you please share with me an example of where an aviation safety regulation has been 'relaxed over time', particularly after such a limited amount of in-service experience for the airplane type in question? I

Wake turbulence standards have changed over time, even the 747 when introduced had about a 10 nm separation standard. Also have a look at http://wwwe.onecert.fr/projets/WakeN...retigny-november/James_Hallock.pdf

Other aspects in aviation where you have seen similar changes would be RVSM (imperial and now metric), RNP, MNP, which like the changes in wake separation standards are designed to get more aircraft in a given volume of airspace.
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OldAeroGuy
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 1:34 am



Quoting Mir (Reply 16):
The standards used to be "no twin engine airplanes beyond 60 minutes of a suitable airport". Those standards then got relaxed, with certain provisions. Then they got more relaxed, with more provisions.

If Airbus can demonstrate that a 380's wake is no different from that of a 747, then the separation will go down. Call it new standards based on demonstrated capabilities if you like, call it a relaxation of standards if you like, but it comes to the same thing.

Hardly. At 60 min ETOPS, there was no standard for engine reliability. Fro 120 min ETOPS, a new tougher safety standard for engine reliability was established, improving safety for both 60 and 120 min ETOPS.

And rather than saying that if the A380 wake is no more adverse, then the standard can be relaxed (ie less safe), the better way to thing about it is that equivalent safety can be maintained by reducing the separation distance.

Of course, the trick is to show that the A380 wake and the 747 wake represent an equivalent hazard so an equivalent separation is appropriate.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
threepoint
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 1:48 am



Quoting Zeke (Reply 17):
Other aspects in aviation where you have seen similar changes would be RVSM

Yup. As soon as I had my debate with Mir, I remembered RVSM. It is, in hindsight, a fairly recent and obvious example.
Now, after some dinner, it seems I have a pdf file to read.
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WingedMigrator
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 4:31 am



Quoting Zeke (Reply 17):
The high lift devices play a major role in the generation of the wake turbulence.

 checkmark 

To first order, the high lift devices determine the speed at which the airplane may fly. Regardless of speed, the airplane must impart a constant rate of downward momentum to the air in order to stay aloft. This constant rate of downward momentum is reacted as lift. The slower the airplane flies, the stronger the wake, since the downward momentum is imparted to a smaller path length of air per unit time.

As you point out, the design details of the high lift devices have a strong influence on how quickly the turbulence decays.

Quoting OldAeroGuy (Reply 5):
No amount of operational familiarity will serve to reduce separation standards.

I'm glad you've come around from this viewpoint.  Wink
 
OldAeroGuy
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 5:29 am

Quoting Zeke (Reply 17):
The simplest example of how you are incorrect is by comparing a 744 landing at the same mass at flap 20 and landing at full flap, they generate different wake turbulence signatures despite having the same physical characteristics.

What are you talking about? Flaps 20 and Flaps 30 (full landing flap) have different physical characteristics. These consist of different flap angles on the fore, main and aft flaps as well as different amounts of Fowler motion. Since the physical characteristics of the flaps change when going from Flaps 20 to Flaps 30, it is no surprise that the wake characteristics are different between these two flap positions.

In addition, landing at Flaps 20 will require a higher landing speed than Flaps 30. The speed change alone will also impact wake characteristics.

Quoting Zeke (Reply 17):
Airbus put a lot of work into the wing design, it has unique leading edge devices, and almost full span high lift devices, a large wing fence, high bypass engines, and a modern airfoil section, all of which influence the high lift characteristics of the aircraft, and subsequently the wake generation.

Aren't these all geometric changes and therefore changes in the airplane physical characteristics, as I stated? Unfortunately, Airbus has not been able to show that these physical characteristics have been able to overcome the primary physical characteristics the A380 impacting wake characteristics (Weight, Span and Approach Speed) to produce wake vortex characteristics that will allow the same separation distance for airplanes in trail as for the 747.

Quoting Zeke (Reply 17):
Quoting OldAeroGuy (Reply 11):
Can you provide a reference where operational experience reduced separation distances for airplanes in trail to the 747?

Good presentation on the development of the current standards http://wwwe.onecert.fr/projets/WakeN...retigny-november/James_Hallock.pdf

I dont think you are aware of a number of the steps given your posts.

Please read my post again and your own reference. I'm very aware of the history of wake separation standards.

Page 3 of your reference shows that the initial separation for the 747 was 10 nm. Page 4 of the reference says that this distance was then reduced to 4 nm for Large airplanes and 5 nm for Small airplanes in trail of Heavies. Note that Page 4 also says that this change was made as the result of flight test data, not operational data. This is what I pointed out previously.

Quoting OldAeroGuy (Reply 11):
No, 747 testing outside of actual operations played a major part in the current separation standards.

The remainder of the reference describes the use of operational data to increase separation distances for other airplanes in trail to Heavies. There is no instance for an airplane in a lower category having its trail distance to a Heavy being reduced. I see no contradiction to my original statement in this reference.

Quoting OldAeroGuy (Reply 11):
Can you provide a reference where operational experience reduced separation distances for airplanes in trail to the 747?



Quoting Zeke (Reply 17):
Any data that is produced from flight testing is "operational" experience, you have made the leap to assume it only means commercial activities.



Quoting Zeke (Reply 17):
Where does it say COMMERCIAL operational experience ?

Commercial operation does seem to be the thrust of this thread. If an A380 is undelivered and does not have an individual airworthiness certificate, then any flight it performs is a flight test.

Quoting Zeke (Reply 17):
Other aspects in aviation where you have seen similar changes would be RVSM (imperial and now metric), RNP, MNP, which like the changes in wake separation standards are designed to get more aircraft in a given volume of airspace.

None of these changes were made solely on the basis of operational data. Physical changes were made to the airplanes to enable the improved operation. Before operational use of these updates were permitted, operational data were collected to ensure that the planned improvements were verified in commercial operation. For example, RVSM was verifed by overflying ground height measuring radar and compared with transponder encoded altitudes. Only when airplanes were shown to have altitude deviations within an acceptable error band was RVSM put into effect.

I'm curious how Airbus will construct a similar operational verification of A380 wake vortex characteristics to allow a reduction in separation distances without endangering trail aircraft. Will Airbus install LIDAR systems at various airports and compare the wake vortex characteristics of 747's and A380's? To make sense of the data, the 747 operators will need to provide operational data for the 747's in the samples. It will be interesting to see if the 747 operators are cooperative.

[Edited 2007-12-11 21:41:19]
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
OldAeroGuy
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 5:33 am



Quoting WingedMigrator (Reply 20):
Quoting OldAeroGuy (Reply 5):
No amount of operational familiarity will serve to reduce separation standards.


I'm glad you've come around from this viewpoint.

Huh? My position is still unchanged.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
Flighty
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 6:07 am

1nm ain't much. Heard anecdotal reports that it's a 5 minute gap, or so. At 200 knots, that's easily 15nm.

Quoting OldAeroGuy (Reply 21):
It will be interesting to see if the 747 operators are cooperative.

I know one 744 operator that would cooperate. Singapore.
 
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zeke
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 6:37 am



Quoting OldAeroGuy (Reply 21):

What are you talking about? Flaps 20 and Flaps 30 (full landing flap) have different physical characteristics.

It seems very clear to myself and others you were trying to push the argument an aircraft with the physical characteristics of mass x and wingspan y will produce a wake of z. You agree with me that two 747-400s that have the SAME physical characteristics and mass can have different wake characteristics just by varying the flap setting used for landing.

Even if you were to scale up the 744 wing and mass by 10%, does not mean you will get 10% more wake.

It is NOT the the physical characteristics of the 744 which generates the wake, it is the physics that produce the lift, and as with anything to do with aircraft design, the number of possible combinations are endless.

It is the improved understanding of the physics which lead to the better wing design on the A380 over the 744, just like better understanding of the physics of engines has seen the improvement of the GEnx over the CF6.

It is the better understanding of the physics that allows the A380 to takeoff and land in distances less than that of a 744, it is the same improved knowledge of the physics which improved the wake generation.

Quoting OldAeroGuy (Reply 21):
Airbus has not been able to show that these physical characteristics have been able to overcome the primary physical characteristics the A380 impacting wake characteristics (Weight, Span and Approach Speed) to produce wake vortex characteristics that will allow the same separation distance for airplanes in trail as for the 747.

With respect, it is obvious to me you have no idea of what Airbus has been able to show.

Airbus does not need to show "same separation distance for airplanes in trail as for the 747", as the 747 is not the upper or lower end of the heavy category. Aviation does not revolve about Boeing, nor do important safety issues like this.

Quoting OldAeroGuy (Reply 21):
There is no instance for an airplane in a lower category having its trail distance to a Heavy being reduced. I see no contradiction to my original statement in this reference.

All of your posts seems like a contradiction, seems like you are back peddling.

Boeing has been adding higher mass, new engine, different wings to the 747 over the years without any testing, all of a sudden when a competitor enters the market segment the competitor has to do a heap of testing and validation work because of what in my view is a campaign launched by Boeing marketing to the industry under the guise of a "safety" problem.

If Boeing were serious about this issue, instead of paying lip service to it they would schedule a scientific analysis of the 787 and 748 wake characteristics during the flight test program.

Quoting OldAeroGuy (Reply 21):
I'm curious how Airbus will construct a similar operational verification of A380 wake vortex characteristics to allow a reduction in separation distances without endangering trail aircraft. Will Airbus install LIDAR systems at various airports and compare the wake vortex characteristics of 747's and A380's?

I have pointed on a number of these wake threads, LADIR has been installed at a number of "normal" airports already, both in Europe and in the US, and research is under the way to have active wake separation based upon reading the real time wake hazard.

Airbus also installed LADIR at controlled airports for scientific testing under EASA/JAA supervision, as well as airborne LADIR measurements for in trail measurements.

Airbus has done the research, and now have the scientific knowledge to be the world leaders in this area.
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
 
OldAeroGuy
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 2:23 pm

Quoting Zeke (Reply 24):
With respect, it is obvious to me you have no idea of what Airbus has been able to show.

As it now stands, they have not been able to convince the EASA/JAA, Eurocontrol and the FAA that the A380 does not require additional separation.

Quoting Zeke (Reply 24):
All of your posts seems like a contradiction, seems like you are back peddling.

If you believe this, then you lack the comprehension to read and understand what I wrote.

Quoting Zeke (Reply 24):
Boeing has been adding higher mass, new engine, different wings to the 747 over the years without any testing, all of a sudden when a competitor enters the market segment the competitor has to do a heap of testing and validation work because of what in my view is a campaign launched by Boeing marketing to the industry under the guise of a "safety" problem.

This is probably the most ridiculous thing I've seen you write. Since the ICAO A380 wake vortex separation working group consists of Airbus, EASA/JAA, Eurocontrol, and the FAA, you're saying that a Boeing PR campaign was responsible for the formation of the working group and has influenced the findings of these organizations. If you can give this thought credence, then you don't know much about how the regulatory bodies function.

Quoting Zeke (Reply 24):
Airbus has done the research, and now have the scientific knowledge to be the world leaders in this area.

But they still have not been able to convince the rest of the ICAO A380 wake separation working group that the A380 does not require additional separation.

[Edited 2007-12-12 06:38:48]
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Cubsrule
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RE: A380 - Any Wash Separation Problems In Reality

Wed Dec 12, 2007 3:48 pm



Quoting Zeke (Reply 24):
Boeing has been adding higher mass, new engine, different wings to the 747 over the years without any testing, all of a sudden when a competitor enters the market segment the competitor has to do a heap of testing and validation work because of what in my view is a campaign launched by Boeing marketing to the industry under the guise of a "safety" problem.

This is hardly bias toward Boeing as you asserted above, though. Derivative aircraft are subject to less rigorous scrutiny than new types. That's true for Boeing, it's true for Airbus, and it's true for every other manufacturer.
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 4:01 pm



Quoting OldAeroGuy (Reply 25):
If you can give this thought credence, then you don't know much about how the regulatory bodies function.

Seems you are the one who does not know what they are talking about.

ICAO is not a regulatory body, this has not been driven by EASA or the FAA, the steering group reported to ICAO. Eurocontrol, FAA etc adopted the ICAO recommendations, not the other way around.

Wake separation not a regulatory issue, it is not a certification issue, if it was, you could quote the FAR/JAR any aircraft needs to be tested with to make the certification requirement.

Quoting OldAeroGuy (Reply 25):
But they still have not been able to convince the rest of the ICAO A380 working group that the A380 does not require additional separation.

How do you know ?

In some phases of flight that is exactly what they are already saying, and for those phases of flight where they have said it is the same, those results went to ICAO in 2004.

The recommendations in place at the moment are nothing but interim recommendations, they are not final by any means. You are constantly trying to imply that things are final and set in concrete, and as myself and others have pointed out, everything is still under review.

I fully support the logic behind what has been done, I would rather them make numerous interim steps based on hard data than not do anything at all.

Quoting Cubsrule (Reply 26):
This is hardly bias toward Boeing as you asserted above, though. Derivative aircraft are subject to less rigorous scrutiny than new types. That's true for Boeing, it's true for Airbus, and it's true for every other manufacturer.

The NTSB recommended that ALL new aircraft undergo analysis of its wake generation, Boeing thinks it does not need to do that. They have admitted that the 748 will have a larger wake than the 744, but we do not know what effect it will have on trailing aircraft.
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Cubsrule
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 4:03 pm



Quoting Zeke (Reply 27):
The NTSB recommended that ALL new aircraft undergo analysis of its wake generation, Boeing thinks it does not need to do that. They have admitted that the 748 will have a larger wake than the 744, but we do not know what effect it will have on trailing aircraft.

Right. Boeing thinks it does not need to do it because it didn't do it for the 742, 742SUD, 743, or 744...
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 4:06 pm



Quoting Cubsrule (Reply 28):
Right. Boeing thinks it does not need to do it because it didn't do it for the 742, 742SUD, 743, or 744...

Boeing has NEVER done it or ANY aircraft.

It does not know what it talking about.
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Cubsrule
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 4:12 pm



Quoting Zeke (Reply 29):
Boeing has NEVER done it or ANY aircraft.

It does not know what it talking about.

I'm not (necessarily) arguing with either of those assertions. However, it's important to note that everyone is playing by the same rules.
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OldAeroGuy
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 4:24 pm



Quoting Zeke (Reply 27):
Quoting OldAeroGuy (Reply 25):
If you can give this thought credence, then you don't know much about how the regulatory bodies function.

Seems you are the one who does not know what they are talking about.

ICAO is not a regulatory body, this has not been driven by EASA or the FAA, the steering group reported to ICAO. Eurocontrol, FAA etc adopted the ICAO recommendations, not the other way around.

Seems that you have another comprehension problem. I described the EASA/JAA, Eurocontrol and the FAA as regulatory bodies, not ICAO.

Quoting OldAeroGuy (Reply 25):
Since the ICAO A380 wake vortex separation working group consists of Airbus, EASA/JAA, Eurocontrol, and the FAA, you're saying that a Boeing PR campaign was responsible for the formation of the working group and has influenced the findings of these organizations. If you can give this thought credence, then you don't know much about how the regulatory bodies function.



Quoting Zeke (Reply 27):
Quoting OldAeroGuy (Reply 25):
But they still have not been able to convince the rest of the ICAO A380 working group that the A380 does not require additional separation.

How do you know ?

In some phases of flight that is exactly what they are already saying, and for those phases of flight where they have said it is the same, those results went to ICAO in 2004.

The recommendations in place at the moment are nothing but interim recommendations, they are not final by any means. You are constantly trying to imply that things are final and set in concrete, and as myself and others have pointed out, everything is still under review.

I eagerly await new guidance from the A380 wake vortex working group. Until they issue it, the recommendation for the A380 will still be increased separation for terminal area operations.

Quoting Zeke (Reply 29):
Quoting Cubsrule (Reply 28):
Right. Boeing thinks it does not need to do it because it didn't do it for the 742, 742SUD, 743, or 744...

Boeing has NEVER done it or ANY aircraft.

Now you're contradicting your own source.

Quoting Zeke (Reply 17):
Good presentation on the development of the current standards http://wwwe.onecert.fr/projets/WakeN...k.pdf

Page 4 clearly states that the 1970 flight test experiments were a joint effort of Boeing, NASA and the FAA.
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 4:24 pm



Quoting Cubsrule (Reply 30):
I'm not (necessarily) arguing with either of those assertions. However, it's important to note that everyone is playing by the same rules.

The rules don't exist, they is why Boeing is trying to put a glass ceiling on the heavy category at 1 million pounds, so they dont need to test the 748.

Separation standards are not standard, the FAA does not follow the ICAO standards.
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Cubsrule
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 4:37 pm



Quoting Zeke (Reply 32):
The rules don't exist, they is why Boeing is trying to put a glass ceiling on the heavy category at 1 million pounds, so they dont need to test the 748.

I hadn't heard that... do you happen to have a source handy?
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CHRISBA777ER
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 4:44 pm

As a derivative of the 747, will the 748 have to undergo the same testing as the A380 has?
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zeke
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RE: A380 - Any Wash Separation Problems In Reality

Wed Dec 12, 2007 5:26 pm



Quoting OldAeroGuy (Reply 31):
Seems that you have another comprehension problem. I described the EASA/JAA, Eurocontrol and the FAA as regulatory bodies, not ICAO.

No problem with comprehension at all.

The Airbus wake vortex group reported to ICAO, which is not a regulatory body. It could have had members from the pink panther fan club, it still does make it a regulatory body, or a function of a regulatory body.

Quoting OldAeroGuy (Reply 31):
I eagerly await new guidance from the A380 wake vortex working group. Until they issue it, the recommendation for the A380 will still be increased separation for terminal area operations.

They have already decreased their recommendations once, and they have given every indication that they will reduce it further again.

The A380 at EIS has lower wake separation requirements than what the 747 did.

Quoting OldAeroGuy (Reply 31):
Page 4 clearly states that the 1970 flight test experiments were a joint effort of Boeing, NASA and the FAA.

Boeing were as much a part of that testing as what they were were with the A380 wake testing when a 777 and 747 were used.

None of the science was directed by Boeing, that came from primarily from NASA and a little from the FAA.That testing was not done by Boeing supervised by NASA/FAA, it was testing by NASA/FAA using Boeing aircraft.

On the A380 front, it was scientific testing lead by Airbus, independently supervised by the FAA, EASA etc.

The two scenarios do not even compare, and as usual disingenuous representation by yourself of the situation in Boeings favor.

Quoting Cubsrule (Reply 33):
I hadn't heard that... do you happen to have a source handy?

Nope, but I do remember it coming up on here earlier this year, not sure when. It may have been in Flight International or on Randys Blog. I remember at the time thinking it was a figure plucked out of thin air without any thinking of what the standards are trying to achieve, i.e. get more aircraft in the same volume of airspace safely.

Quoting CHRISBA777ER (Reply 34):
As a derivative of the 747, will the 748 have to undergo the same testing as the A380 has?

The wake characteristics of an aircraft are not currently a regulatory or certification item, therefore the 747-8 or 787 cannot rely on "grandfather" rights of previous designs.

At the same time no regulation currently exists that would require the 747-8 or the A380 to be tested, that appears to be changing http://www.flightglobal.com/articles...vortex-rules-set-for-shake-up.html
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Cubsrule
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 5:30 pm



Quoting Zeke (Reply 35):
The A380 at EIS has lower wake separation requirements than what the 747 did.

I'm not sure what, if anything, that proves. You can hardly compare 1960s technology to current technology, and obviously, we have far more experience with large aircraft now than we did then.

Quoting Zeke (Reply 35):
Nope, but I do remember it coming up on here earlier this year, not sure when. It may have been in Flight International or on Randys Blog. I remember at the time thinking it was a figure plucked out of thin air without any thinking of what the standards are trying to achieve, i.e. get more aircraft in the same volume of airspace safely.

Thanks; I'll do a little digging and see if I can find it. I must have missed it when it was discussed here the first time.
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 5:39 pm



Quoting Cubsrule (Reply 36):
You can hardly compare 1960s technology to current technology, and obviously, we have far more experience with large aircraft now than we did then.



 checkmark 

I agree totally, and it why Airbus is using science to show the A380 poses no more danger than other large aircraft to trailing aircraft.

What the science has also shown, is that the current weight bands do not accurately represent the hazard an aircraft can be to a trailing aircraft.
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moo
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 5:40 pm



Quoting Cubsrule (Reply 36):
You can hardly compare 1960s technology to current technology, and obviously, we have far more experience with large aircraft now than we did then.

Then why do grandfathering rights stand?
 
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 5:45 pm



Quoting Moo (Reply 38):

Then why do grandfathering rights stand?

That's a darn good question. In the U.S. at least, very little grandfathering actually appears in Part 25 (our certification regulations for transport category aircraft), and most grandfathering is simply a courtesy to manufacturers. So in theory, if the FAA saw something that was unsafe, they could refuse to grandfather it. Whether that's the best practice is, I think, an open question.
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zeke
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RE: A380 - Any Wash Separation Problems In Reality?

Wed Dec 12, 2007 5:50 pm



Quoting Moo (Reply 38):

Then why do grandfathering rights stand?

Interesting philosophical question that deserves its own thread.

I think they were put in place for simple derivatives of a base certified airframe, I dont think they were ever envisaged to cope with fundamental changes like the difference between a 737-100 and a 737-900ER, or the 747-100 and the 747-8 that cover 30 years of aviation accidents, investigations, safety recommendations, and amendments to the design rules.
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Cubsrule
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RE: A380 - Any Wash Separation Problems In Reality

Wed Dec 12, 2007 5:59 pm

Quoting Zeke (Reply 40):
I think they were put in place for simple derivatives of a base certified airframe, I dont think they were ever envisaged to cope with fundamental changes like the difference between a 737-100 and a 737-900ER, or the 747-100 and the 747-8 that cover 30 years of aviation accidents, investigations, safety recommendations, and amendments to the design rules.

Well said. The 737, 747, and CL-600 are probably the three best examples of inappropriate, but perfectly legal, grandfathering.

Had Airbus built the 330 before the 340, they might have tried certifying the 330 as a 300NG... I'm not sure how far that effort would have gotten.

[Edited 2007-12-12 10:00:48]
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tdscanuck
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RE: A380 - Any Wash Separation Problems In Reality?

Thu Dec 13, 2007 5:36 am



Quoting Zeke (Reply 24):
Boeing has been adding higher mass, new engine, different wings to the 747 over the years without any testing, all of a sudden when a competitor enters the market segment the competitor has to do a heap of testing and validation work because of what in my view is a campaign launched by Boeing marketing to the industry under the guise of a "safety" problem.

You can substantiate something by analysis or by test. If you have a giant pile of existing data and your change is incremental, analysis is almost always cheaper and usually just as good. That's why Boeing doesn't typically do a full up test it on derivatives. The A380 had not prior data that could be used for a valid substantiation by analysis, so they had to test.

Quoting Zeke (Reply 24):
If Boeing were serious about this issue, instead of paying lip service to it they would schedule a scientific analysis of the 787 and 748 wake characteristics during the flight test program.

Why would you do it during flight test? You can do the analysis long before that using wind tunnel data and known flight test data for similar derivatives. That's what Boeing does today.

Tom.
 
OldAeroGuy
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RE: A380 - Any Wash Separation Problems In Reality?

Thu Dec 13, 2007 10:27 pm

Zeke, You have quite a style on this discussion board.

First, you write something that is not factual.

Quoting Zeke (Reply 29):
Quoting Cubsrule (Reply 28):
Right. Boeing thinks it does not need to do it because it didn't do it for the 742, 742SUD, 743, or 744...

Boeing has NEVER done it or ANY aircraft.

It does not know what it talking about.

Then when I point out your error, you respond that I'm being disingenuous and print another untruth stating that the only involvement Boeing had with the 1970 wake vortex testing was to build some of the subject airplanes.

Quoting Zeke (Reply 35):
Quoting OldAeroGuy (Reply 31):
Page 4 clearly states that the 1970 flight test experiments were a joint effort of Boeing, NASA and the FAA.

Boeing were as much a part of that testing as what they were were with the A380 wake testing when a 777 and 747 were used.

None of the science was directed by Boeing, that came from primarily from NASA and a little from the FAA.That testing was not done by Boeing supervised by NASA/FAA, it was testing by NASA/FAA using Boeing aircraft.

On the A380 front, it was scientific testing lead by Airbus, independently supervised by the FAA, EASA etc.

The two scenarios do not even compare, and as usual disingenuous representation by yourself of the situation in Boeings favor.

It's clear you do not have a clear understanding of the 1970's tests. If you're interested in correcting this deficiency, I suggest you get a copy of this document:

FAA-Flight Standards Service, A Compilation of Working Papers Concerning the Wake Turbulence, 30 April 1970.

It's the first reference in the link you provided in Reply 17.

Quoting Zeke (Reply 17):
Good presentation on the development of the current standards
http://wwwe.onecert.fr/projets/WakeN...k.pdf

You can order a copy from this source:

http://stinet.dtic.mil/oai/oai?verb=...taPrefix=html&identifier=AD0724589

If you read the document, you'll find that:

- Four Boeing owned airplanes participated: 747, 707-320C, 737-100, F-86
- The Boeing owned airplanes were flown by Boeing test pilots
- Boeing, FAA, and NASA engineers worked side-by-side to design the experiments, analyze the data, and make airplane separation recommendations.

These tests were ground breaking as the 747 and C5A were the first "Heavies". Testing was different than today (no LIDAR available), but represented the best available technology. They formed the basis for safe operation behind "Heavies".

Unfortunately this document is not available on the Web. In case you still have doubts about Boeing's involvement in 747 wake vortex testing, I direct you to the following document that is available on the Web.

http://wwwe.onecert.fr/projets/WakeN...2_WG5_Literature-Overview_v1d4.pdf

Please note the first paragraph on page 2:

"The Boeing Company initiated a study of large jet airplane wake vortices in mid-1969 [3]. The objective was to obtain a direct comparison between the vortices of a 747 and 707-320C. A fully instrumented 737-100 was used as the primary wake probing aircraft. Additional tests were conducted with a Boeing owned F-86 and NASA's CV-990. The 737 was also flown into the wake near the ground. The Boeing tests were aimed at providing a direct comparison between the 747 and a representative aircraft of the current fleet. the 707-320."

Please note the title of the [3] document is Results of the Boeing Company Wake Turbulence Test Programme by P. M. Condit and P. W. Tracy. Condit and Tracy were Boeing Company employees.

From these reference and links, it is obvious that your statements regarding Boeing having never done wake vortex work on the 747 and not being involved in the FAA/NASA wake vortex testing are patently false.

Now for a few additional comments:

Quoting Zeke (Reply 27):
Quoting OldAeroGuy (Reply 25):
If you can give this thought credence, then you don't know much about how the regulatory bodies function.

Seems you are the one who does not know what they are talking about.

ICAO is not a regulatory body, this has not been driven by EASA or the FAA, the steering group reported to ICAO. Eurocontrol, FAA etc adopted the ICAO recommendations, not the other way around.

Wake separation not a regulatory issue, it is not a certification issue, if it was, you could quote the FAR/JAR any aircraft needs to be tested with to make the certification requirement.

Actually you changed the subject. I was responding to your ridiculous claim the ICAO A380 Wake Turbulence Working Group had been created due to a Boeing PR campaign.

Quoting Zeke (Reply 24):
Boeing has been adding higher mass, new engine, different wings to the 747 over the years without any testing, all of a sudden when a competitor enters the market segment the competitor has to do a heap of testing and validation work because of what in my view is a campaign launched by Boeing marketing to the industry under the guise of a "safety" problem.

It was the thought that a Boeing PR campaign could influence the FAA, EASA/JAA, Eurocontrol or ICAO into launching an investigation of a competitor's airplane that prompted my response. If you think this, then you don't know how these organizations function. You yourself say that new aircraft wake vortex testing is a recommendation of the NTSB.

Quoting Zeke (Reply 27):
The NTSB recommended that ALL new aircraft undergo analysis of its wake generation

Who do you think carries more weight with the FAA? The NTSB or Boeing?

On the subject of regulation, not all rules that regulate the operation of aircraft require certification. You won't find the BAA's QC System in the FAR's/JAR's, but it certainly does regulate operation into and out of LHR. Likewise, ETOPS is not a certified operational condition, but the FAA and EASA certainly regulate airplanes and airlines for ETOPS operations. In the same vein, wake turbulence separation is most certainly a regulatory issue since it regulates how closely one airplane may operate in relationship to another.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
aerokiwi
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RE: A380 - Any Wash Separation Problems In Reality?

Fri Dec 14, 2007 11:04 am

Such a strange thread. OldAeroGuy simply points out that issues such as aircraft separation and ETOPS are only ever changed/updated based on non-operational testing or technological developments and suddenly it becomes an AvB thing!

Zeke - rather than getting all defensive about the A380, perhaps you should go back and read the earlier posts and you'll realise there is nothing to be defensive about. No one was passing judgement, only stating fact. I have to say, I've learnt quite a bit from this thread.
 
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RE: A380 - Any Wash Separation Problems In Reality?

Fri Dec 14, 2007 12:04 pm



Quoting Aerokiwi (Reply 44):
I have to say, I've learnt quite a bit from this thread.

Ditto Ak. I too regret the tone that developed as we were starting to find out some interesting material though the exchanges were still interesting.

What would be nice would be to have some data on how the effects of the weight of a plane on wake turbulence are affected by wing span, wing loading, tip geometry, approach speeds, flap geometry and whatever else I have forgotten about.

Presumably, as approach speeds decrease, the kinetic energy in the wake decreases in a non-linear fashion??? What happens to the decay time for vortices generated at lower rather than higher speeds? Presumably they also decrease in a non linear fashion.

One bit of non-news that might be taken as positive. I have not seen any reports of missing tiles from aircraft since the A380 starting landing in Sydney - as opposed to the missing tiles from hailstorms of which there has been quite a few. Big grin ?  thumbsup 
 
sllevin
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RE: A380 - Any Wash Separation Problems In Reality?

Fri Dec 14, 2007 9:02 pm



Quoting Zeke (Reply 17):
Other aspects in aviation where you have seen similar changes would be RVSM (imperial and now metric), RNP, MNP, which like the changes in wake separation standards are designed to get more aircraft in a given volume of airspace.

I thought RVSM required equipment better than originally required? IOW, the standard changed because the underlying requirements changed.

Steve
 
ikramerica
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RE: A380 - Any Wash Separation Problems In Reality?

Fri Dec 14, 2007 9:14 pm



Quoting OldAeroGuy (Reply 43):

Thanks for setting the record straight. I get annoyed when people knowingly post false information on these forums, and it's helpful to have the facts presented to counter, from people with knowledge and credibility.

RR +10!  Smile (and yes, I do mean 10 factorial...  Wink )
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zeke
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RE: A380 - Any Wash Separation Problems In Reality

Fri Dec 14, 2007 10:07 pm



Quoting Tdscanuck (Reply 42):
You can substantiate something by analysis or by test. If you have a giant pile of existing data and your change is incremental, analysis is almost always cheaper and usually just as good. That's why Boeing doesn't typically do a full up test it on derivatives. The A380 had not prior data that could be used for a valid substantiation by analysis, so they had to test.

I agree that the A380 should have been tested, but we also had the C5, AN124, AN225 flying about for some time.

Quoting Tdscanuck (Reply 42):
Why would you do it during flight test? You can do the analysis long before that using wind tunnel data and known flight test data for similar derivatives. That's what Boeing does today.

Boeing know less about the 744 wake than what Airbus does, it has does the modeling and validated that with flight testing.

The 787/748 do not have similar derivatives. The 748 wing is very different to the 744, let alone a 747-100.

Quoting OldAeroGuy (Reply 43):
Then when I point out your error, you respond that I'm being disingenuous and print another untruth stating that the only involvement Boeing had with the 1970 wake vortex testing was to build some of the subject airplanes.

They are not Boeing tests, I did not say Boeing were not involved, just they were not Boeing tests. Being a participant does not mean you have ownership of the process, i.e. participating on a.net does not make you the owner of the site and all the data.

They were NASA/FAA tests (http://www.nasa.gov/centers/dryden/about/Organizations/Technology/Facts/TF-2004-14-DFRC.html). If they participated fine, but that does not give ownership of the test to Boeing. The A380 tests were Airbus tests, not ICAO, EASA, FAA, NASA, EUROCONTROL, and I still stand by my statement Boeing never testing their aircraft, the tests were designed/overseen by NASA/FAA not Boeing.

The way you are posting is that Boeing lead the research and performed the tests themselves, which is not true. Boeing has NEVER does this for any aircraft.

Quoting OldAeroGuy (Reply 43):
FAA-Flight Standards Service, A Compilation of Working Papers Concerning the Wake Turbulence, 30 April 1970.

FAA tests

Quoting OldAeroGuy (Reply 43):
- Boeing, FAA, and NASA engineers worked side-by-side to design the experiments, analyze the data, and make airplane separation recommendations.

Still not a Boeing test

Quoting OldAeroGuy (Reply 43):
Please note the title of the [3] document is Results of the Boeing Company Wake Turbulence Test Programme by P. M. Condit and P. W. Tracy. Condit and Tracy were Boeing Company employees.

In this document http://gltrs.grc.nasa.gov/reports/20...20Systems/C3-01-PrimeggiaPaper.pdf that paper is listed as being an FAA paper, not Boeing.

"Condit, P.M., April 1970, “Result of the Boeing Company Wake Turbulence Test Program”, Wake Turbulence Tests, FAA Washington, DC."

Quoting OldAeroGuy (Reply 43):
From these reference and links, it is obvious that your statements regarding Boeing having never done wake vortex work on the 747 and not being involved in the FAA/NASA wake vortex testing are patently false.

Still stand by what I said..which I tried to clarify for you exact in reply 35 "None of the science was directed by Boeing, that came from primarily from NASA and a little from the FAA. That testing was not done by Boeing supervised by NASA/FAA, it was testing by NASA/FAA using Boeing aircraft."

I have not seen anything you present to suggest that this is incorrect.

Quoting OldAeroGuy (Reply 43):
Actually you changed the subject. I was responding to your ridiculous claim the ICAO A380 Wake Turbulence Working Group had been created due to a Boeing PR campaign.

Boeing PR and yourself have been having a go at the A380 for years, nothing has changed on that front.

And if you do not think that FAA, EASA, ICAO etc do not react to the industry concerns, you are sadly mistaken.
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dakota123
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RE: A380 - Any Wash Separation Problems In Reality?

Fri Dec 14, 2007 11:38 pm

Frankly I would be more inclined to trust results of NASA (for example) than a proponent such as Airbus (or Boeing, for that matter).

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