777X fails stress test

BlueMoon

Well-Known Member
Cliffs notes for the lazy crowd?
Several Gulfstream actions, as explained in detail in sections 2.3 through 2.5, led to the circumstances surrounding the accident. Specifically, during the G650 program,

Gulfstream overestimated the actual in-ground-effect stall AOA for the G650 during the accident flight, resulting in the AOA threshold for stick shaker activation being set too high and the flight crew not receiving any warning before the actual stall occurred;

used a flawed assumption in determining the takeoff speeds for the G650, resulting in V2speeds that could not be achieved because they were too low;

exacerbated the error in V2speeds before the accident flight by decreasing the target pitch angle for some continued takeoff flights without an accompanying increase in the takeoff speeds;

failed to fully investigate two previous uncommanded roll events that occurred during G650 field performance flight testing;

focused on refining pilot technique to resolve the V2overshoot problem (so that the G650 takeoff performance guarantee could be achieved) instead of investigating the root cause for theV2overshoots; and

 

DE727UPS

Well-Known Member
I flew a lot of ex-TWA 727-100's in the 90's at UPS. I wonder if I flew Hoot Gibson's plane in it's second life. Those 727's were tough birds.

PS: Upon further review, it's was at Express One and then Emery during my 727 tenure.
 
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SeanD

Well-Known Member
777-8X & 777-9X. Basically a newish carbon fiber wing and updated engines. Bigger and trying to be a 747 replacement, with two engines.
What was wrong with the current 777 airframe? Changing the wing and engines on an existing airframe hasn’t really worked out for them.
 

Ecl!pse

Well-Known Member
What was wrong with the current 777 airframe? Changing the wing and engines on an existing airframe hasn’t really worked out for them.
The current 777 is not really competitive with its new challenger, the A350, which is both lighter and has more fuel efficient engines. At the very least the current 777 needed next-generation engines to be competitive, but even with next gen engines it's still too heavy to be competitive, so Boeing stretched it and extend its wingspan to try and improve it's per-seat efficiency. After you include the cost of ownership, the 777x still really not competitive at the end of the day, which is why it's sold so poorly.
 

Roger Roger

Paid to sleep, fly for fun
The current 777 is not really competitive with its new challenger, the A350, which is both lighter and has more fuel efficient engines. At the very least the current 777 needed next-generation engines to be competitive, but even with next gen engines it's still too heavy to be competitive, so Boeing stretched it and extend its wingspan to try and improve it's per-seat efficiency. After you include the cost of ownership, the 777x still really not competitive at the end of the day, which is why it's sold so poorly.
I thought the 787 was more the direct equivalent of the 350?
 

Eskhobbs

Well-Known Member
The current 777 is not really competitive with its new challenger, the A350, which is both lighter and has more fuel efficient engines. At the very least the current 777 needed next-generation engines to be competitive, but even with next gen engines it's still too heavy to be competitive, so Boeing stretched it and extend its wingspan to try and improve it's per-seat efficiency. After you include the cost of ownership, the 777x still really not competitive at the end of the day, which is why it's sold so poorly.
What? The A350 and 777x aren't even in the same market segment...
 
What? The A350 and 777x aren't even in the same market segment...
The A350 was supposed to originally be an A330 replacement. But then they F-35'd it and gave it multiple missions. A 787 fighter and also a 777 fighter. Not sure if its doing too well in those regards. There's already talk about an A350 NEO. After the A350-1000 wasn't quite up to the task.
 

Ecl!pse

Well-Known Member
I thought the 787 was more the direct equivalent of the 350?
The A350 has better payload/range than the 787, so not exactly a direct equivalent but they will compete for orders.

What? The A350 and 777x aren't even in the same market segment...
They both are and they aren’t, but I’ll come to that in a second.

The original poster asked why the current 777 needed a refresh. It needed a refresh because there was an advance in WB engine technology and the new A350 was significantly more efficient from a fuel burn and cost perspective. The A350-900 is a replacement for the 777-200ER and the A350-1000 is a replacement for the 777-300ER. Boeing had to respond in some form to the A350, as the 787 comes up short on payload/range capability.

Like the 787/A350 in the first part of the post, the 777x has greater payload/range capability than the A350, so yes it is in a different market segment.

However, current 777 operators will be faced with a choice: upgauge their 777’s to 777X’s, which has more capacity and more range, or switch to the A350 which is a closer match for payload/range and saves ~20-25% fuel per seat. In this way, the two types will surely compete.

Unfortunately for the 777X (but fortunately for the 787), the widebody market is moving away from VLA’s altogether, instead favoring fragmentation/downgauging. This means that A380, 747, and even current 777 operators are all looking much closer at A350’s at the top end, or A330neos/787s at the low end.

The 787-9 and 787-10 seems to be the current sweet-spot of the wide body market, but if you’re looking for more payload/range above that, the A350 is the best bet. Unfortunately, outside of the ME3, nobody is really looking for that much payload/range anymore.
 
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Crop Duster

E pluribus unum
So they get 1% below a passing score and still "pass"
It's a freaking WITCH HUNT against Boeing.

Is there really a difference between 69% and 70% on a written test? Is there really a difference between being 20 miles out and 21 miles out during a 20 mile TFR? Is there really a difference between being just below versus just above stall speed during landing flare? Is there any difference between chugging 1500 miles across the country and stopping correctly versus stopping 8 feet long?? C'mon, get with the modern age. If it FEELs right, and enough of your cronies say it's right, then you're an expert... Facts, and Experts, and Science, and Measurements, and Standards, and UCMJ, and Constitutional Law, and actual breaking points be damned.

It's the end of the world as we know it, and I feel fine.

train.jpg
 
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Boris Badenov

Someone should definitely do *something*, Captain!
It's the end of the world as we know it, and I feel fine.
Oh, damn your eyes. I was merrily harrumping away and nodding vigorously (almost knocked the cheaters off my forehead), then you had to throw in the f'ing REM ear-worm. GET OUT OF MY HEAD, MICHAEL STIPE!

Hey. Hey. WE DIDN'T START THE FIRE. There, that's what you get. Enjoy!
 
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