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Air Force Plans New Blended Wing Body Cargo/Tanker Aircraft by 2027

airandspaceforces.com

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Re: Air Force Plans New Blended Wing Body Cargo/Tanker Aircraft by 2027

#81

Post by DocTomoe »

walrus01 wrote: post #34

I think that a blended wing body design extremely similar to this was one of the more radical proposals on the table, when they were developing the budget and concept for the 787. Ultimately ended up with a carbon fiber bodied more conventional aircraft of course. Reading the URL, I think that anything about the Air Force caring about a climate action plan, or environmental sensitivity, is window dressing to say that…

> concept for the 787

Such designs come up every once in a while in civil aviation - but then disappear, mostly because they would require new (expensive) airport infrastructure.

Just remember that when the A380 came out, every major airport that was a viable A380 destination started increasing their landing strip length, assuring the taxiways could handle the extra weight, worked on their baggage handling and check-in capacity and created gates that had more boarding bridges.

Now imagine what basically triangular aircraft would mean for that infrastructure.

Re: Air Force Plans New Blended Wing Body Cargo/Tanker Aircraft by 2027

#82

Post by DocTomoe »

ars wrote: post #47
chrisseaton wrote: post #4

Earlier quoted context omitted.

Do they do all those evacuation tests with able-bodied volunteers? How would they evacuate for example five wheelchair users within the 90 seconds or whatever is required for the test?

Not only is the test with able bodied people, they also are permitted to practice first to make the time. But - the test handles this by only giving them 90 seconds. In the real world it would take far longer, but rather than testing a longer, more realistic test, they do a really fast one instead.

The test is about whether such an evacuation is theoretically possible, not if it is realistic under any conceivable circumstance (half the plane gone, blocked exits, plane resting at an incline, smoke and/or fire and/or water in the cabin...).

If the happy-path evacuation isn't possible to begin with, e.g. for design reasons, the more complicated realistic ones will be negatively affected as well.

Re: Air Force Plans New Blended Wing Body Cargo/Tanker Aircraft by 2027

#83

Post by DocTomoe »

walrus01 wrote: post #35
d_silin wrote: post #2

Blended-wing body makes a lot of sense for cargo/tanker aircraft. No issues with emergency evacuation procedure for passengers.

Also no issues with passengers caring that they don't have a window seat, or aren't even anywhere near in the view of a window.

So I flew Emirates First the other day. They now have virtual windows in some suites, which are linked to cameras outside of the plane. That worked surprisingly well, and after a few moments I forgot about having booked an aisle seat.

I would expect this to eventually be rolled out more widely and later replacing real windows, which are structural weak points of the hull and heavy. Also, for our Ryanair no-frills flyers: they are screens where you can show ads.

For the Emirates experience, see https://www.youtube.com/watch?v=VdDzaNlGSmk

Re: Air Force Plans New Blended Wing Body Cargo/Tanker Aircraft by 2027

#84

Post by metaphor »

adolph wrote: post #19
mauvehaus wrote: post #7

The KC-46 program has not gone swimmingly. I'm curious how they think they're going to get a demonstrator flying in 5 years when they can't get a tanker that's based on an existing production airframe flying on schedule. https://en.m.wikipedia.org/wiki/Boeing_KC-46_Pegasus

P8 went pretty well. Blended wing isn’t sci-fi, B2 and plenty of ucav are full flying wing. https://en.wikipedia.org/wiki/Boeing_P-8_Poseidon

> P8 went pretty well.

Did it really?

According to this fairly recent GAO report[1], the Poseidon's mission capable rates have missed their minimum 80% target since 2015, trending downwards (Table 1); only the first 2 out of 7 years were satisfactory (Figure 7), and yet those years' metrics were based on Increment 1 low-rate initial production lot that were "not effective for the intelligence, surveillance and reconnaissance mission" and "not effective for wide area anti-submarine search" that they were originally intended for[2].

Even in early years when maintenance staff was stacked balls deep at well over 100% (Figure 5), persistent supply issues plagued the platform, trending upwards (Table 5). To be sure, this outcome was entirely predictable; e.g. picking on Northrop Grumman's Electronic Support Measures system[3] that the Bloomberg article calls out as just one example: if you knew how the sausage was made, then this 2006 GAO report[4] which highlights certain risks "of particular concern" surrounding ALQ-218 development is all of sudden prescient in that it took so long to get the underlying system to acceptable maturity on the Growler that it became a very real commercial obsolescence sustainment risk by the time the Poseidon's full-rate production decision was made!

[1] https://www.gao.gov/products/gao-22-104533

[2] https://archive.ph/356bG

[3] https://news.northropgrumman.com/news/releases/northrop-grum...

[4] https://www.gao.gov/products/gao-06-446

Re: Air Force Plans New Blended Wing Body Cargo/Tanker Aircraft by 2027

#85

Post by rjsw »

edrxty wrote: post #32
InTheArena wrote: post #27

Earlier quoted context omitted.

Boeing was a very very different company then. I’m bullish on blended wing body, but I would have much more confidence if it were Lockheed or someone emulating the SpaceX, rapid development cycles working on this.

As someone in industry, I can assure you Boeing is still a disaster. I know a fuckload of good people who have turned down working there because the culture is shit and management is braindead even by defense contractor standards.

I'm working with Boeing people on a project, having their email system randomly fail to deliver incoming messages doesn't help.

Re: Air Force Plans New Blended Wing Body Cargo/Tanker Aircraft by 2027

#86

Post by actionfromafar »

sbierwagen wrote: post #64
pinko wrote: post #53

Earlier quoted context omitted.

Baffles are typically used to control this, even in conventional aircraft fuel tanks. It's a non-issue.

I mean, baffles aren't free, since they add empty weight and reduce payload. The designers will be tempted to keep them to a minimum. There definitely will be at least some free surface effect and slosh.

Plastic bags to reduce slosh?

Re: Air Force Plans New Blended Wing Body Cargo/Tanker Aircraft by 2027

#87

Post by actionfromafar »

Aloha wrote: post #65
KerrAvon wrote: post #52

Earlier quoted context omitted.

“Give us a 737 but more crashy” is also not what their customers really wanted. There were surely more possibilities available than just the two extremes of “737 but crashes more” and “tiny Concorde.”

Had the software worked as intended, no one would have noticed.

That's the problem - it's not clear to me that it could have worked as intended. But you can easily get that impression in high level meetings I imagine.

Re: Air Force Plans New Blended Wing Body Cargo/Tanker Aircraft by 2027

#89

Post by nickfromseattle »

skybrian wrote: post #6

They say there's a lot more volume, but would it carry more weight, and where would the weight have to be placed? Why isn't this design used commercially?

>Why isn't this design used commercially?

In a commercial plane, passengers will rise/drop during turns relative to the center line, but it's minimal due to distance from center line.

The further out passengers are from the center line, the more they will drop/rise during turns.

Imagine being seated towards the outer edge of this fuselage. You might rise/drop 20-30ft off the centerline during a turn.

Re: Air Force Plans New Blended Wing Body Cargo/Tanker Aircraft by 2027

#90

Post by sofixa »

mauvehaus wrote: post #7

The KC-46 program has not gone swimmingly. I'm curious how they think they're going to get a demonstrator flying in 5 years when they can't get a tanker that's based on an existing production airframe flying on schedule. https://en.m.wikipedia.org/wiki/Boeing_KC-46_Pegasus

> The KC-46 program has not gone swimmingly

That's what happens when protectionism gets involved. The Boeing design (based on an existing plane, but with some new systems and a combination of components from different generations of 767s) was chosen over the proven, already in production A330 MRTT. Delays and cost overruns are to be expected.

Same thing with ships, in the end US Navy had to accept it's not that special and it ended up ordering an RFP based on existing off the shelf designs (with the Franco-Italian FREMM winning).

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