Boeing 747-8 needs wake vortex tests

A350XWB · Post by **A350XWB** » 21 Jun 2007, 05:24

Boeing’s new 747-8 widebody will need to undergo trials to determine aircraft separation for wake turbulence avoidance.

Wake vortex tests are “clearly something we’re going to have to do” for the 747-8, the program’s VP marketing Randy Tinseth confirmed today at a Paris air show briefing.

http://www.flightglobal.com/articles/20 ... tests.html

CX · Post by CX » 21 Jun 2007, 15:17

Not much different to the 744, surely won't cause drama like the A380 in this respect.

David747 · Post by **David747** » 21 Jun 2007, 16:22

Is Boeing grandfathering the 747 certification, or is the 747-8 Certification being treated as a new plane?

RC20 · Post by **RC20** » 22 Jun 2007, 07:45

Because the 747-8 has the same wing span (very close) as the A380, its just not as wide, there is going to be some difference (and a new wing). Good move to find out, which is the right way to go about it.

The grandfather issue is still in discussion. Boeing certified the 747 with up to 550 people (I think only JAL ever used that capacity on that short dense domestic route they flew). While the new one will seat 475 (I am doing this off the top of my head, so it could be off by some), I don’t think anyone plans on that many. Emirates might be the only one that might as they do have the seasonal high density pax loads.

Boeing contends as none of the seating plans exceeds the original certification, and therefore they do not have to run the tests again. I think it’s a legitimate claim.

I know Airbus went for the higher numbers, but they could have tested at actually numbers. I think testing at the higher numbers let them claim the higher seating capacity (and I think it’s a legitimate advertisement for the A380 and its capabilites, even if no one uses it).

An annoyance I have, is that all the seat claims and cost per seat stuff, really means nothing as you have to have the exact seat plan for any given airline to actually evaluate what it means. You also need to know route lengths and which engine (RR 3 spool engines have an advantage only if the route is long enough).

Add into that what the typical actual load is. Occasionally a flight will be full, but normally you see (when things are going well) of 70-80% load factors. If you had all that information, then you could actually determine who has what advantage.

Of course those figures all change within an airline as well, so you have to take an average, and try to figure out if you are better off loosing on efficiency on some routes, vs having max efficiency but a lot of different types of aircraft.

PYX · Post by **PYX** » 22 Jun 2007, 08:50

RC20 wrote:Boeing certified the 747 with up to 550 people (I think only JAL ever used that capacity on that short dense domestic route they flew).

The 747SR had 525 seats and the 747-400D has 568 seats.
In October 2002, I had the worst travel experience of my life when I spent 7 plus hours on a JAL 747-400D flight from NRT to SIN. If you are over 5' 6" tall you will not enjoy flying on a 747-400D.
A week later, just by happenstance, I found myself talking with a gentleman who said he was the head of Boeing 747 production. When I told him my story he sounded a bit concerned and asked twice if I was sure I had been on a -400D. He went on to say that Boeing had an agreement with JAL that the -400D was not to be flown outside of the Islands of Japan.
Oh, well.........

Best laid plans and all that......

smokejumper · Post by **smokejumper** » 22 Jun 2007, 14:02

PYX wrote:
RC20 wrote:Boeing certified the 747 with up to 550 people (I think only JAL ever used that capacity on that short dense domestic route they flew).
The 747SR had 525 seats and the 747-400D has 568 seats.
In October 2002, I had the worst travel experience of my life when I spent 7 plus hours on a JAL 747-400D flight from NRT to SIN. If you are over 5' 6" tall you will not enjoy flying on a 747-400D.
A week later, just by happenstance, I found myself talking with a gentleman who said he was the head of Boeing 747 production. When I told him my story he sounded a bit concerned and asked twice if I was sure I had been on a -400D. He went on to say that Boeing had an agreement with JAL that the -400D was not to be flown outside of the Islands of Japan.
Oh, well......... Best laid plans and all that......

Along the same lines, I flew from London to Washington, DC last year on a BA 747-400 (coach) and even with the seat forward, was constantly "kneed" in the back by the passenger behind me. He was tall and his knees just kep giving me an annoyning and uncomfortable massage!

PYX · Post by **PYX** » 24 Jun 2007, 23:23

Thanks for the warning. Sounds like they must be as bad as JAL, which I'll never fly again. One leg of that journey was on a old JAL DC-10 and it was pleasure as compared to the way they have configured their B-747-400s. I prefer the B747-400 to any other commercial aircraft, but not JALs -400s.
The Boeing 777-200 comes in a close second as the most comfortable aircraft I've flown.

HorsePower · Post by **HorsePower** » 25 Jun 2007, 16:30

AFAIK, the world's record concerning the B747-400 density is still decerned to a french carrier: CRL operates B747-400s with 587 seats !!!
(and no, this is not for regional ops...)