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Thirty Eight South
20th Jun 2007, 20:32
Boeing 747-8 needs wake vortex tests according to Flt Int

Boeing’s new 747-8 widebody (http://www.boeing.com/commercial/747family/747-8_facts.html)will need to undergo trials to determine aircraft separation for wake turbulence (http://en.wikipedia.org/wiki/Wake_turbulence)avoidance.


add to that the cost problem with Boeing's alleged EASA 787 certification costs (red herring award) and it's an interesting turn up for the books. The trouble with using a competitors certification criteria ambiguities, is that it can bite you on the arse:ipso facto in this case. Oh dear.
broadreach
22nd Jun 2007, 01:06
That's an interesting one. Under what circumstances is a more efficient wing going to create more wake turbulence?
ft
22nd Jun 2007, 09:44
When carrying a heavier aircraft.
canuck slf
23rd Jun 2007, 01:22
I realize this is a bit off topic, however does anybody know if the 747-8 will cruise level as opposed to the current 747-400 nose high attitude inherited from the original design?
chornedsnorkack
25th Jun 2007, 15:55
however does anybody know if the 747-8 will cruise level as opposed to the current 747-400 nose high attitude inherited from the original design?
I suppose it would be technically stupid to try. DeltaL/DeltaD diverges at minimum drag.
LoadMan
13th Jul 2007, 13:31
That's an interesting one. Under what circumstances is a more efficient wing going to create more wake turbulence?For example at take-off and landing with a different slat/flap system.
broadreach
13th Jul 2007, 18:33
Loadman, sounds reasonable. I.e. it's more efficient at cruise but, at low speeds, the extensions will be proportionally greater than its predecessor's.

Ft, "when carrying a heavier aircraft" ok. What about at the same gross though?
LoadMan
14th Jul 2007, 00:05
I think the B747 was never assessed well. I think it makes sense to have a more serious investigation on the wake vortex issue. It may increase the data and finally lead to more reasonable seperations. Airbus has gained quite a knowledge on this issue and many ideas about seperations have come out of this. The whole thing was treated very briefly the last two decades.