Y Combinator Startup Podcast - Building A Supersonic Plane Company From The Ground Up

Episode Date: February 14, 2025

Imagine flying from NY to London in just a few hours. That’s the future that Blake Scholl and his team at Boom Supersonic are working towards. Blake started as a software engineer and pivoted mid-career to aviation. Now, he’s at the forefront of trying to bring back supersonic travel for all of us. In this episode of Hard Tech, YC’s Jared Friedman visited Blake in the Mojave desert to find out how someone who didn’t have a background in aerospace engineering was able to build the first-ever independently developed supersonic plane.

This is Boom Supersonics XB1. It's the first independently developed supersonic plane in history. There we are. XB1 is supersonic. Pasta and the speed of sound. But the XB1 is essentially a prototype. The next step is to build a supersonic passenger airplane that you and I can fly in. We are here to bring back supersonic passenger travel and ultimately to make the planet

dramatically more accessible. Blake Scholl is the founder and CEO of Boom Supersona. The way I got to Boom was to ask myself, if everything I might work on, what would personally make me the happiest if it worked? And I knew I wanted to work on flight. If every founder just worked on the most ambitious thing they'd get their head around,

everyone's going to be a lot happier and a lot more great things are going to get built. I've been following Blake and his team at Boom for nearly a decade. And recently, I was lucky enough to join them in the Mojave Desert for the XB1's historic flight. During our trip, I got the chance to sit down with Blake. In our discussion, we talked about the history of supersonic flight, how he went from being a product manager at Groupon to the founder of Boom, and how he took Boom from a crazy

idea to a working airplane. What are we looking at behind us? Well, that's the XP-1. History's first independently developed a supersonic jet, and we built it because we wanted to learn 100% of the lessons required to build a supersonic jet safe for passengers out of technology we could deploy on an airliner. One analogy is XB1. That's kind of like our Falcon 1. That was the first time that anybody outside of a nation state had put something in orbit. And SpaceX did that to prove they could do it, and then moved on to the Falcon 9. Overture is like

our Falcon 9. All of this is leading to the overture, a supersonic airliner that will carry around 65 passengers and travel at Mach 1.7 while running on 100% sustainable fuel. They've even figured out a way to prevent sonic booms from reaching the ground, which will allow them to fly over land, a major hurdle for past attempts at supersonic passenger travel. The goal for overture is to start carrying passengers by 2029. How did you get the idea to work on this? And how did you get the company off the ground? Yeah, so I had set a lifetime goal in my 20s of flying supersonic. After I've been seen at Concord in a museum in Seattle, I just put a Google order on a supersonic jet. In decades past, people regularly flew at Mach 2.

on the Concord. The Concord was developed as a joint venture between the French and British governments in the 1960s. It carried passengers from New York to London at supersonic speeds from the mid-70s until 2003 when it was finally shuttered. The Concord was too expensive to operate and never fully lived up to its potential. And when it shut down, technological progress reversed itself. The future I want to live in is one where flights that are at least twice as fast as what we have today are totally retained, taken for granted. Help us understand. Help us understand what this is going to mean for regular people as passengers. Supersonic is going to come to market much the way many other new technologies do,

where they start at relatively higher price points and then come down, just electric cars, cell phones, computers. Concord was kind of out in No Man's Land, a $20,000 ticket adjusted for inflation, and Overture version one is going to be like flying business class today. So imagine Tokyo to Seattle in four and a half hours, New York to London, about three hours in 45 minutes. But being able to do that at about the same fare you have in business class today.

Blake has loved plane since he was a kid and has a private pilot's license. But he didn't pursue aviation professionally until he was in his 30s. Before that, he studied computer science in college and his first career was building websites at Amazon, Groupon, and his own startup. My background was in the tech world.

I started my career at Amazon as a software engineer. After Amazon, he worked at the mobile startup, Palago before co-founding his own startup. My first company was a barcode scanning game. I knew e-commerce and I'd worked at one of the first iPhone app companies. So I figured I knew mobile. So I thought I should put those together and work on what I knew. I should work on mobile e-commerce.

What I found was chasing what I thought I knew gave me a sense of competence, but it gave me no sense of purpose or drive. I think that I've come to believe is that knowledge and skills are variable. I think smart people underestimate what they can learn, particularly if they're motivated. But what you can't change is your passions. If you go after something that inspires you, you can go find that you can create skills and knowledge that you didn't have before. After having sold my first company to Groupon, I wanted to work on something that would be inspiring that I would never want to give up on no matter how hard it was. And so I figured, obviously, someone will go do this.

Someone will pick up where Concord had left off. And I was just waiting for, you know, waiting to find out when I could buy a ticket. But it was crickets. And I didn't know why. And so when I got to that point of being ready to do my next company, I thought, okay, I never want to be 80 years old looking backwards and wondering what if I tried. So I thought, okay, I got to get this out of my system. I got to look at it, understand for myself, why it's a bad idea, and then move on. And so my first question was why did Concord fail?

The answer was not technology. And the answer was economics. At that point, I figured I had to get a lot smarter. So I bought every textbook I could find. I took an airplane design class. I took remedial calculus and physics from Khan Academy because I hadn't had either since high school. Another thing I've come to believe is particularly for what people call,

you know, hard tech or deep tech, where the technology development timelines and costs are longer, one of the biggest ways you can fail is to build something that nobody wants. So you've got to mature the concept of the market, along with the concept of the product and be really honest that there will be product market fit for the eventual thing. And so my first question was why did Concord fail? The answer was economics. It was a $20,000 ticket, 100 uncomfortable seats. The thing flew half empty. And then the question became, well, how much would you have to do better than Concord on just fundamental efficiency of the airplane in order to make those economics work? A business class fair, a seat instead of a bed. And it literally took two weeks to have to have.

that question and then I got to the point in the middle of 2014 where I had a spreadsheet model of the airplane and a spreadsheet model of the market. One tab was like global air travel, you know every route in the planet, how many seats, at what fares, and how much the speed up would be with a certain crew speed of the airplane, and then there's the other tab which is about the technical stuff, what would be the lift-drag ratio, what would be the engine fuel economy, what would be the structural efficiency of the airplane. And it turns out you can predict the performance of an airplane with really just four inputs.

Aerodynamic efficiency, lift to drag ratio, propulsive efficiency, structural efficiency, and lower numbers are better. If you've got those three numbers plus the mock number, you can really predict the whole airplane. And then the output is as good as the assumptions. So I had that model. I had taken it to a professor at Stanford, and I said, look, dude, I've been at this for like two seconds. I don't know what I'm doing. But are the assumptions reasonable?

And he said, Blake, if you're going to do this, you should try harder because all these assumptions are conservative. it. And I remember leaving his office and thinking, if that's true, either I have no courage, or I'm going to go find some engineers and we're going to make a run at this. And I think that's one of the advantages that I had coming to aerospace from the outside is, you know, I didn't have time to go get a four-year degree, let alone a PhD, let alone spend 10 years at Boeing. I had to go look for the fundamental truths. And they are surprisingly accessible. So I spent the next six months networking. And day zero, I didn't know a single. person in the industry. I remember going to go to LinkedIn, filter industry equals aerospace,

connection equal first degree, and literally there's no results. Wow. My first intro was a guy who had worked for me at Groupon and played hockey in college of somebody who now worked at SpaceX. That was how you broke into the airspace industry. So I would write these, you know, intro request blurbs that were like, hey, I've got an airplane design idea and I'd love to get your advice. And I'm happy to fly to you and buy you lunch. And you'd like fly around the country. Yeah. Well, I did, you know, so that was my only cred back then. I could show up in an airplane that I flew myself. That helped more than, more than I thought it would. I would go meet basically as many people as I could. Every time I met somebody, I would describe what I was doing and tried to convince

them I wasn't insane. And then say, if you could wave a magic wand and get anybody in the planet to come work with you on this, who would your top five people be? Don't forget whether they're available, forget whether they're interested, forget whether, you know, forget everything other than, would this be one of the top five humans on the planet to do this? I would ask that question recursively, and it turns out, it turns out, you don't need many levels of recursion before I was actually talking to the best people on the planet. So that was how I found the initial team. But for the first 18 months, I thought there's like no way I could possibly be the human that had found the formula for a supersonic passenger flight. And it was actually very liberating. It's like, today will be the day

that I find the bug in the spreadsheet. But after a while, it was like, if the math was wrong, I would know by now. What did everybody else get wrong? All these supposed experts in aerospace who thought that this idea was crazy, why did everybody else miss this simple insight that you can get with a three-line spreadsheet?

I think it's a form of the bystander effect. Supersonic flight would so obviously be a good thing. Nobody's doing it. There must be something wrong. There must be a good reason why. Right, and then the internet was full of bad reasons why. One form of which is giving a qualitative answer to a quantitative question. People won't pay more for speed.

It's all about cost. The market's too small unless you can fly supersonic over land. Sonic booms are too loud. These are all qualitative claims about quantitative topics. I was fortunate that I left Groupon, I put aside a year of my life to just figure out what I wanted to do next. And so I could kind of go down this rabbit hole without worrying too much that it could be a blind alley. And I think nobody else went down it. This is not some, you know, amazing deep fundamental physical insight that you need 20 PhDs to go accomplish. It definitely makes me wonder

how many other ideas like that are lying in plain sight, waiting for someone who's ambitious enough to just like defy the bystander effect and like stand up and say, well, I'm going to do it. I think they're actually a lot. How big is the team? How old are they? How do they know how to do this? They're about 50 people. 50 people. This whole airport. This whole airport. plane was built by essentially 50 people. By 50 people. Yeah. Small, high caliber teams can do things that big teams can't do. Those constraints breed a lot of innovation.

We looked for evidence of having done meaningful things. A lot of the team was young. They came from places like SpaceX. We'd find people earlier in their career at Boeing before they were corrupted and steal them. Generally early career, the hardest ones to get were the ones that had been around the loop a couple times, but had not gotten destroyed by big aerospace. You don't get a bunch of experts that have been there, done that, know it's impossible. You want a handful of them on speed dial to prevent you from making foolish mistakes to help

you see around corners. You've got to listen to them only the right amount. That's my belief. Beyond that, smart, ambitious, hardworking, and incredibly passionate. That's the formula. How have you managed to do this so quickly with so few people, basically just a core team of 50, a relatively modest amount of money by aerospace standards. I mean, if we knew on day one what we knew today,

we could have done it half the time for a third of the money. We made a lot of mistakes along the way. We knew we would. That's why we did a test airplane because we wanted to learn those mistakes because it's cheaper to iterate in a small airplane than it is on a big one. Building a supersonic jet is ridiculously hard. It's not possible. It's not impossible.

You're in this pretty unique position because you built both a traditional software startup. And you went through YC with a hard tech company, which a lot of people don't even realize is a thing. What advice would you have for founders who are like just starting out? They want to start a company. They don't really know what their path is. What have you learned? Founder motivation, I think, is really, really important and it's undervalued.

The thing that has enabled me to go through a zillion things and never give up is just belief in how important it causes. The world needs supersonic flight. Passengers deserve it. So there are days that I get up and there's a problem. that I don't know how we're going to solve, and there are days where I question whether I'm the person who can pull this off, but there is never a day where I don't think it's worth giving to everything I've got.

The story of Boom shows that founders don't need to be constrained by their on-paper credentials and that the most ambitious startup ideas are surprisingly achievable and sometimes hiding in plain sight. Startups are hard. My first company had like high highs and low lows, and Boom is high highs and low lows. I think ambitious founders, we're going to run at our personal red line. And being at that personal red line, being at that I don't know if I've got what it takes, that's going to feel the same way at any company.

So you may as well work on something. You might as well work on something really big.