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Boom (YC W16) – Supersonic Passenger Airplanes

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Re: Boom (YC W16) – Supersonic Passenger Airplanes

#411

Post by jonathankoren »

bscholl wrote: post #192

Hi - I'm Blake, Founder/CEO at Boom. After watching no tangible progress in supersonics since Concorde was shut down, I started Boom because I want supersonic flight in our lifetime. Not just as a private jet, but something most anyone can afford to fly. Will try to answer as many questions here as I can.

Wasn't the problem that made the Concorde uneconomical fuel prices? While a barrel of oil is currently trading at around $41, I don't think many economists believe that this is a long term trend, and expect prices to rise back to around $80 - $100. Isn't this a strategic problem?

Re: Boom (YC W16) – Supersonic Passenger Airplanes

#412

Post by pbreit »

shrewduser wrote: post #400
dsyko wrote: post #398

Earlier quoted context omitted.

Also given the association that "boom" has with explosions, a very bold name choice.

i am also perplexed

I am not even slightly perplexed. It's a great name and great mission and I wish them well.

Re: Boom (YC W16) – Supersonic Passenger Airplanes

#413

Post by paulmd »

bertil wrote: post #254
kilroy123 wrote: post #181

Earlier quoted context omitted.

Very skeptical this little company can go all the way with this. Look at how hard it is to get a new automobile company up and running. Tesla almost went completely bankrupt more than once. I do think there is a need and market for faster than sound air travel. We have the technology to even minimize the sonic booms for over land travel. Still, it would take an enormous amount of capital to get a new company up and r…

I am not saying this is easy, but what they need to do is build one airplane, and get it to fly back and forth. That is nothing like the scalability and repeated reliability that building thousands of car is asking for. I know several people (starting by my brother) who build their own plane (granted, it was a two-seater several several times louder than a grass-mower and seemingly slower, but you get the idea). One…

Your brother's plane is likely an ultralight or light-sport category, and regardless as a kit-built is nowhere near the certification required for commercial operation. A key requirement of kit-built or experimental aircraft is that you can't ask money to fly passengers on them. He's not even allowed to ask for gas money if you take a trip together.

Commercial requirements literally start at "one aircraft that gets the wings overstressed (if not actually snapped off) during destructive testing" and the requirements continue steeply onwards from there. You can figure on having it built by FAA-certified mechanics as well.

The FAA likes having a paper trail if the wings fall off (an extremely common problem with ultralight/sport aircraft built by non-certified personnel). Not OK when you're carrying passengers for hire.

Re: Boom (YC W16) – Supersonic Passenger Airplanes

#414

Post by hanspeter »

monk_e_boy wrote: post #134
URSpider94 wrote: post #124

Earlier quoted context omitted.

You have just described a huge fraction of my adult life. Take my word for it, being there in person is still the only way to close critical business deals.

This. That's why silicon valley. That's why working remotely doesn't work very well for most people. Non verbal communication is very important for trust.

Now I'm imagining a meeting in silicon valley where participants are using only sign language.

Re: Boom (YC W16) – Supersonic Passenger Airplanes

#415

Post by lisper »

elliotec wrote: post #361
bvi wrote: post #304

Earlier quoted context omitted.

Honest / naive question. How do you even start an aerospace company "in your basement"?

Blueprints, math, models.

Or start by building a small plane, which you can do in a (large) basement.

Re: Boom (YC W16) – Supersonic Passenger Airplanes

#416

Post by taneq »

kuprel wrote: post #395
schwarrrtz wrote: post #245

Earlier quoted context omitted.

The specific energy of kerosene is ~40 MJ/kg [0] while the specific energy of lithium ion batteries is ~1 MJ/kg [1]. Unsure how much energy you'd save from the difference in drag, but I'd guess that significant improvements in electric energy storage would be required to make an electric plane doable. [0] https://en.wikipedia.org/wiki/Kerosene#Properties [1] https://en.wikipedia.org/wiki/Lithium-ion_battery

Specific energy of hydrogen is 142 MJ/kg. Why not a hydrogen fuel cell powered electric jet?

Because hydrogen is very hard to store in any reasonable size or shape, and that's even without focusing on the inefficiency of generating it.

Re: Boom (YC W16) – Supersonic Passenger Airplanes

#417

Post by SeoxyS »

mikeyouse wrote: post #307
schwarrrtz wrote: post #245

Earlier quoted context omitted.

The specific energy of kerosene is ~40 MJ/kg [0] while the specific energy of lithium ion batteries is ~1 MJ/kg [1]. Unsure how much energy you'd save from the difference in drag, but I'd guess that significant improvements in electric energy storage would be required to make an electric plane doable. [0] https://en.wikipedia.org/wiki/Kerosene#Properties [1] https://en.wikipedia.org/wiki/Lithium-ion_battery

To be fair to our electric friends, electric motors are >90% efficient while turbofans top out at somewhere near 35% efficiency (as far as I can find).. So what appears to be a 40:1 advantage to kerosene is more like a 15:1 advantage -- substantial but much more accessible with ongoing battery improvements. Though as another commenter mentioned, fuel planes do definitely benefit from shedding weight the entire time t…

A jet engine (e.g. turbofan) relies on combustion in the engine in order to function. The ignition of the fuel from within the engine is key… it is not just there to just create energy to drive rotational force. You would you use an electric motor on a plane without going back to what is essentially a propeller design?

Re: Boom (YC W16) – Supersonic Passenger Airplanes

#418

Post by maaku »

privong wrote: post #358
bscholl wrote: post #208

Earlier quoted context omitted.

Thanks! We are very excited to be doing this. We're starting out focused on long flights that are mostly over water, like New York - London or San Francisco - Shanghai. Around an airport, our airplane will be about as quiet as other new aircraft. The sonic boom will also be much quieter—and we'll continue to make future iterations even quieter. It's hard to say exactly when, but I expect the supersonic overland ban w…

> It's hard to say exactly when, but I expect the supersonic overland ban will be reversed in the coming years. Can you elaborate on this? Is there a significant lobbying effort for this or is it something the FAA is considering of their own volition, to stimulate activity in this area?

NASA Ames has been doing some great research (in the bay area no less) on boomless supersonic crafts. There are basically two strategies: either modify the fuselage to disrupt the boom wavefront, or redirect the wavefront by going supersonic at a nontraditional attack angle. Both work.

Re: Boom (YC W16) – Supersonic Passenger Airplanes

#419

Post by maaku »

kuprel wrote: post #395
schwarrrtz wrote: post #245

Earlier quoted context omitted.

The specific energy of kerosene is ~40 MJ/kg [0] while the specific energy of lithium ion batteries is ~1 MJ/kg [1]. Unsure how much energy you'd save from the difference in drag, but I'd guess that significant improvements in electric energy storage would be required to make an electric plane doable. [0] https://en.wikipedia.org/wiki/Kerosene#Properties [1] https://en.wikipedia.org/wiki/Lithium-ion_battery

Specific energy of hydrogen is 142 MJ/kg. Why not a hydrogen fuel cell powered electric jet?

Drag on a bigger airframe.

Re: Boom (YC W16) – Supersonic Passenger Airplanes

#420

Post by sschueller »

hellyeasa wrote: post #410

Sorry, this is ridiculous, it just wont happen (not ever, just this company). From my experience in the aerospace industry, having a manned prototype aircraft of this scale fly within 2 years, supersonic no less (!!), is an impossibility. It is simply not possible, at least with any sane regard for safety. Aircraft are hard, you need an army of experienced engineers, like thousands, and hundreds of millions of dollar…

I sadly agree. I would love to see a supersonic business jet but the regulatory requirements alone to get a new aircraft certified takes years.

Even the new Pilatus PC-24 (small business jet) announced in 2013 is not expecting to ship until 2017. The second prototype just went airborne. [1]

[1] https://en.wikipedia.org/wiki/Pilatus_PC-24

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