Truss-braced airliner - Boeing/NASA X-66A

[FourWheelDrift]

https://www.flightglobal.com/airframers/boeing-ceo...

High mounted wing, means bigger engines can be fitted longer supported wing can be more efficient.

[GliderRider]

Discussed here in January: Truss-Braced Airliner

Its seems odd that they've taken a stretched fuselage version of a design and are shortening it, however the streched ones are probably the newest and closest to airworthy.

[BrettMRC]

Looks draggy?

[dr_gn]

I wonder why they didn’t place the engines at the intersection of the brace and the wing, and use the nacelle as an interface? Would have got rid of the pylon, and the top of the nacelle could have been used to transfer wing loads through to the fuselage.

[Simpo Two]

dr_gn said:

I wonder why they didn’t place the engines at the intersection of the brace and the wing, and use the nacelle as an interface?

Perhaps too far out to be controllable in the event of an engine failure?

[TGCOTF-dewey]

dr_gn said:

I wonder why they didn’t place the engines at the intersection of the brace and the wing, and use the nacelle as an interface? Would have got rid of the pylon, and the top of the nacelle could have been used to transfer wing loads through to the fuselage.

Nacelles are noy structural though so you'd have to go to RR, etc for a redesign = cost. Makes it hard to drop an engine too.

[dr_gn]

TGCOTF-dewey said:

dr_gn said:

I wonder why they didn’t place the engines at the intersection of the brace and the wing, and use the nacelle as an interface? Would have got rid of the pylon, and the top of the nacelle could have been used to transfer wing loads through to the fuselage.

Nacelles are noy structural though so you'd have to go to RR, etc for a redesign = cost. Makes it hard to drop an engine too.

I meant they'd be designed to be structural. It's like you've got an intersection of three elements, then added a fourth (the pylon). Intuitively at least, it seems a bit inefficient, in terms of drag.

[Simpo Two]

dr_gn said:

I meant they'd be designed to be structural. It's like you've got an intersection of three elements, then added a fourth (the pylon). Intuitively at least, it seems a bit inefficient, in terms of drag.

Though against that, the wings are high aspect ratio which would reduce drag.

Let's form an aeroplane company - 'Armchair Aeronautics'!

[shouldbworking]

Hard to judge at a glance. Would there would be a higher risk of spanging something into the ground in the event of banking during landing (downdrafts etc)?

[eharding]

TGCOTF-dewey said:

dr_gn said:

I wonder why they didn’t place the engines at the intersection of the brace and the wing, and use the nacelle as an interface? Would have got rid of the pylon, and the top of the nacelle could have been used to transfer wing loads through to the fuselage.

Nacelles are noy structural though so you'd have to go to RR, etc for a redesign = cost. Makes it hard to drop an engine too.

Not to mention what putting an engine at the wing/brace intersection would do to the centre of gravity.

[Some Gump]

Hmm. CEO of Boeing, NASA’s experiments and a wind tunnel..
Vs car website forum judging by a CGI graphic…

It’ll be an interesting debate, especially with the opening gambit from Boeing being “if it behaves in real life like it did in the wind tunnel it’ll see service”.

I’m not a gambling man, but I feel that maybe the engineering team considered “what if we put the engine there instead?” And “hmm it looks draggy”.

Great to see “different” being tested either way. Like G1. lMP1 when it wasn’t cack etc - great to see alternative solutions and ideas get real funding