XB-1's wings are officially closed out • Hacker News Board

Re: XB-1's wings are officially closed out

#111

Post by elil17 » Sat, Apr 18, 2020, 3:13 AM UTC

trhway wrote: post #6

i'm in no way qualified to give any praise/criticism, it just caught my attention (from the linked post on their cockpit/fuselage bonding https://blog.boomsupersonic.com/20-hour-bonding-event-speeds... ) "It’s the following morning and bonding appears to be successful, but it’s essential to confirm that the bond lines are shaped correctly or “filleted.” A member of the engineering team, who is certified in the proces…

You can scale composite manufacturing significantly (as Boeing and Airbus have) using layup robots.

Re: XB-1's wings are officially closed out

#112

Post by flyinglizard » Sat, Apr 18, 2020, 3:20 AM UTC

robotresearcher wrote: post #99

flyinglizard wrote: post #87

Earlier quoted context omitted.

Fuel cost is far from being the dominating factor in TCO; that would be depreciation. I just ran Edmunds TCO calculator on an Audi A6: 5 year TCO of $70k, with depreciation over 5 years being $35k and fuel only contributing $9k. Electric cars are nowhere near an affordable means of transportation right now (that would be a Hyundai Accent), so GP point stands true.

How does the A6 compare with Model 3?

Haven’t compared the two up close but the Audi is bigger and probably has a nicer interior because that’s what Audi excels at. I’m inclined to give the rest to the Tesla.

Re: XB-1's wings are officially closed out

#113

Post by TheSpiceIsLife » Sat, Apr 18, 2020, 3:23 AM UTC

trhway wrote: post #19

Justin_K wrote: post #12

Earlier quoted context omitted.

Yea, not very scientific. Seems like ultrasonic tests would be good here. I think they do something similar to check welds on ships.

yes, ultrasound on ship welds, and if i remember correctly - on some forged and other way fabricated/processed parts too. X-ray on even more important stuff like nuclear plant welds ("China Syndrome" has nice depiction around it).

We do mostly structural steel at work. Some jobs require all welds to be inspected using ultrasound and magnetic particle tests, so we weld to that standard pretty much all the time on every job.

Re: XB-1's wings are officially closed out

#114

Post by chrismorgan » Sat, Apr 18, 2020, 3:26 AM UTC

elil17 wrote: post #104

ricardobeat wrote: post #27

This is quite scary for a non-engineer. You're telling me that this little supersonic plane has the whole wing structure held together by a handful of 4mm thick metal struts, manually glued to the wing surface, with wire pulleys running on the inside :O

Glue is sort of the wrong word. When you hear glue you maybe imagine the general purpose glue that you can buy, like Elmers glue or Super Glue. This is a chemical adhesive designed specifically for the surfaces that it's holding together (i.e., they will use a different glue for composite-to-metal bonds than metal-to-metal, etc.) and it's very strong. Many things you wouldn't expect are glued together. Many weld and…

And these bonds can be stronger than the base materials, so that it’s actually least likely to break where you glued it.

Re: XB-1's wings are officially closed out

#115

Post by badfrog » Sat, Apr 18, 2020, 3:29 AM UTC

earthtourist wrote: post #75

I like the idea of supersonic passenger jets existing again. I'm not sure I really see the point though. Would you rather fly in business class comfort for 8 hours or with less comfort for 4 hours? Almost doesn't seem worth the expense and risk of going supersonic. I would be so much more excited about an airplane that was large enough that economy class seating was as comfortable as business class seating is today.…

> Would you rather fly in business class comfort for 8 hours or with less comfort for 4 hours?

I'd take the 4 hours any day. At that point, it's reasonable to take a trip to Europe for a long weekend.

Re: XB-1's wings are officially closed out

#116

Post by robotresearcher » Sat, Apr 18, 2020, 3:33 AM UTC

scoopertrooper wrote: post #101

robotresearcher wrote: post #98

Earlier quoted context omitted.

Concorde's first flight was 1969 and ran commercially until 2003. High end demoed.

I don’t get the point you are trying to make here. The concord used a certain set of technologies and this aircraft uses another set of technologies with their own challenges. I mean I guess the concord was also a large supersonic passenger plane, but the similarity is largely superficial.

I was responding to a point about supersonic transport, not this plane.

Re: XB-1's wings are officially closed out

#117

Post by rconti » Sat, Apr 18, 2020, 3:39 AM UTC

babesh wrote: post #53

jupp0r wrote: post #43

From their web page: “Faster travel brings the world’s people, cultures, and experiences within reach. Life happens in person, and at Boom we see breaking the time barrier as a moral imperative. XB-1 is the first step in bringing supersonic travel back to the world.” -- Blake Scholl, Founder and CEO The life happens in person part currently sounds like a relic from the past. I hope Boom makes it through the travel re…

They are targeting $5K for round trip tickets between NY and London. It is really just making it faster for the rich to travel for fun or work. Supposedly it is inherently 3X as expensive as subsonic planes from a cost per seat mile point of view. It is basically a cheaper replacement for the Concorde. Also it seems that their biggest difficulty is coming up with suitable engines. The engines that they need don't exi…

Seems fine-ISH. At least they're selling a different product.

In theory, as an SV DINK, I should be able to afford business class. But every time I try to pull the trigger on the tickets, it just kills me. What, $1400 coach and $7000 business? Times two people? Are you effing kidding me? Those business class seats do NOT take 5 times the space. And they want you to pay double ($2800 or so) for 'premium economy' which is a footrest, "economy plus" legroom (eg, a $100 upgrade), and a bit more shoulder room. Again, it's not 2x the space of a coach seat.

If they're gonna charge 3x as much, and provide a vastly different service, I'm all ears. Even if the seats suck just as much as a coach seat, at least I'm in it for a much shorter time.

Re: XB-1's wings are officially closed out

#118

Post by rconti » Sat, Apr 18, 2020, 3:40 AM UTC

lmm wrote: post #107

robotresearcher wrote: post #98

Earlier quoted context omitted.

Concorde's first flight was 1969 and ran commercially until 2003. High end demoed.

It wasn't commercially successful enough to continue operating - partly because it wasn't permitted to fly supersonically over the continental US, through some combination of being too noisy and not being made in the US. Boom is the next iteration that addresses that.

I mean, a 34 year run is a pretty good proof of concept. They weren't running on Sand Hill VC bucks.

Re: XB-1's wings are officially closed out

#119

Post by rconti » Sat, Apr 18, 2020, 3:42 AM UTC

robotresearcher wrote: post #99

flyinglizard wrote: post #87

Earlier quoted context omitted.

Fuel cost is far from being the dominating factor in TCO; that would be depreciation. I just ran Edmunds TCO calculator on an Audi A6: 5 year TCO of $70k, with depreciation over 5 years being $35k and fuel only contributing $9k. Electric cars are nowhere near an affordable means of transportation right now (that would be a Hyundai Accent), so GP point stands true.

How does the A6 compare with Model 3?

That's absurd. An A6 is a much bigger/nicer car than a Model 3. I'd say the A6 is Model S territory, both in size and price. Of course this is complicated by the lower running costs of the S, but the much more spartan interior, which was basic even in 2012.

I've got a Model 3. It's a fantastic car, and as a BMW fan, I'd choose it all day every day over a BMW 3 series. But I'd take the A6 for the same price.

Re: XB-1's wings are officially closed out

#120

Post by loeg » Sat, Apr 18, 2020, 3:44 AM UTC

jamestimmins wrote: post #82

phire wrote: post #72

Earlier quoted context omitted.

This demonstrator is a 1/3 scale model of their final design. It allows them to prove their exact final design will be quiet, along with verifing the rest of the aerodynamics.

Any idea how often the final design and the prototype don't match in terms of volume and aerodynamics? I would have assumed that those parts are the easiest to model with high confidence.

Aerodynamics modeling is incredibly difficult. You could probably test a smaller scale model, though (probably they have).