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

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

#101

Post by scoopertrooper » Sat, Apr 18, 2020, 2:20 AM UTC

robotresearcher wrote: post #98

friendlybus wrote: post #62

Earlier quoted context omitted.

If supersonic travel were ever to be the norm it has to start at the high end first like Tesla did.

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.

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

#102

Post by google234123 » Sat, Apr 18, 2020, 2:34 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…

Wait, they don't actually have engines that they can buy that would fit their specs? That seems like a serious issue. There's no way they could fund the design of an engine.

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

#103

Post by myrandomcomment » Sat, Apr 18, 2020, 2:58 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…

JAL is one of their planned customers that invested. I make the SFO to Tokyo flight every month. This takes that flight from 11 hours to 3.5. It is not about being rich. At the same cost of a business ticket it means that I do not have to leave on Saturday in SFO to make a Monday meeting (leave Sat. at 3pm and land in Tokyo at 7PM Sunday). I get more time at home with my family.

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

#104

Post by elil17 » Sat, Apr 18, 2020, 2:59 AM UTC

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 rivet connections on cars have been replaced with glue in the last few years.

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

#105

Post by jupp0r » Sat, Apr 18, 2020, 3:02 AM UTC

flyinglizard wrote: post #87

tinco wrote: post #66

Earlier quoted context omitted.

They are though. Tesla is a horrible example, electric cars have better fuel economy, so should have a lower TCO for daily users in the long run. Which has always explicitly been Tesla's goal in the long run. This plane, while awesome, is not a Tesla, it's never going to be as cheap as a commercial flight, and it's certainly not going to make the world a better place.

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.

Part of Teslas proposition is that leaving out the combustion engine will also reduce maintenance cost and reduce TCO that way.

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

#106

Post by TheSpiceIsLife » Sat, Apr 18, 2020, 3:02 AM UTC

chrischattin wrote: post #51

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

Airplanes are very strong, but very delicate. Really amazing works of engineering.

Have you seen that F15 perform a carrier landing with one wing mostly blown off?

https://youtu.be/M359poNjvVA

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

#107

Post by lmm » Sat, Apr 18, 2020, 3:02 AM UTC

robotresearcher wrote: post #98

friendlybus wrote: post #62

Earlier quoted context omitted.

If supersonic travel were ever to be the norm it has to start at the high end first like Tesla did.

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.

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

#108

Post by elil17 » Sat, Apr 18, 2020, 3:04 AM UTC

gr2020 wrote: post #68

Somewhat OT - but from their FAQ they say they're targeting a price of $200M for the Overture. I'm certainly no expert, but this feels to some extent a bargain given the capability. Capacity 55-75 passengers. A few data points for comparison (all of these approximate of course, with multiple variants available of each): Airbus A220 - $90M Airbus A320neo - $110M Boeing 787 - $140M Boeing 777 - $320M Airbus A350 - $325…

Additionally, if you cut your trip time in half you double the number of trips you can take. This is why the metric is Available Seat Miles. In a way it's like making a plane with a capacity of 110-150 pax.

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

#109

Post by elil17 » Sat, Apr 18, 2020, 3:07 AM UTC

tqi wrote: post #54

This test plane has a range of 1k nautical miles but a cruising speed of Mach 2.2, which works out to like 40 minutes of flight time at max speed? That seems like a really tight window for takeoff + test + land + any kind of safety buffer. I'd be curious to know how they handle those logistics.

They have a safety reserve of fuel. They fly it in the desert so they can glide to a landing anywhere. And plenty of your time will be below max speed (since air resistance is non-linear, your fuel consumption is much lower during these times).

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

#110

Post by elil17 » Sat, Apr 18, 2020, 3:09 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.

You don't need to build it to test volume and aerodynamics (math and wind-tunnels can figure that out for you). This is probably more about finding unknown flaws in the design/running down risk. Spending however much on a prototype (10s or 100s of millions of dollars) just to marginally reduce the risk that there's a fundamental flaw in your approach makes a lot of sense when you plan to spend 6 billion total to develop the plane.