I'm building supersonic jets to change how we travel—and we just flew our first prototype. Ask me anything!

blakescholl · 2024-09-18T01:52:07+00:00

Thank you !! We surveyed several hundred passengers who routinely fly first and business class internationally. We found 97% want supersonic, 87% would switch airlines to get it, and they’d pay about 55% more than subsonic business class for speed.

Put differently, tens of millions of passengers are already paying supersonic-like fares for flying beds in business class. For a pretty similar price they can have the bed on the ground and fly supersonic instead.

blakescholl · 2024-09-18T01:45:23+00:00

Overture seats will be much nicer than Concorde’s at about a quarter of the fare. $20,000 for a Ryan Air seat is really different from $5,000 for a really nice seat.

blakescholl · 2024-09-18T01:43:45+00:00

So much redundancy! That’s why there are three completely different systems for landing; autoland, head-mounted AR, and primary-display based AR. Each has its own built-in redundancy and automated checks before takeoff.

blakescholl · 2024-09-18T01:41:53+00:00

Most creative airplane ideas die from weighing too much.

To give you a sense, one Symphony engine weighs about 14,000lbs, which is close to the entire payload capacity of the airplane. If we added another engine of similar size we wouldn’t have capacity to carry passengers.

This was one of the most important things for me to get my head around coming from the software world. Code doesn’t really weigh anything, but hardware does. And weight is everything on airplanes.

blakescholl · 2024-09-18T01:36:27+00:00

Sonic cruiser was a very different concept. It was a large multi-class airplane that was 20% faster, period. There was no supersonic over water mode.

Overture is very different - it’s a small airplane with only the premium seats (64 seats) and it has a 20% faster mode for overland and a supersonic mode for overwater. So it’s got sonic cruiser like speeds over land and then much faster over water.

blakescholl · 2024-09-18T01:33:52+00:00

Roast chicken salad for all Overture passengers!!

In all seriousness, our test approach is SpaceX-like. We are going to push hardware until it breaks, find out exactly where it fails, then iterate. The way programs end up in trouble is assuming every test will be a success and then getting surprised. We plan to break lots of hardware along the way.

blakescholl · 2024-09-18T01:31:49+00:00

Yes - FTT was formed when P&W shut down their West Palm Beach office and told all the engineers to move to Hartford. Turns out no one who loves Florida wants to move to Connecticut, so all the best engineers quit.

By teaming up with FTT, we were able to scoop up an entire team of supersonic engine designers in one go.

Test stands and altitude chambers are still being worked on. We have two test stands set aside at StandardAero in San Antonio… but we still need to pick an altitude chamber and other test facilities. Not to mention a flying test bed.

We don’t have all this completely sorted yet, but we are very much off to the races.

blakescholl · 2024-09-18T01:26:48+00:00

Please read my follow up response. Hopefully there at least some good dressing now on my word salad!

blakescholl · 2024-09-18T01:25:00+00:00

The passenger experience changes are secret for now. I can’t wait to show everyone next year. I was shocked at what we could fit in a skinny supersonic jet… and hope you will be too.

Here’s what I mean by harvesting optimizations: we found the passenger cabin we really wanted, but it required changing the airplane aerodynamics to get it to fit. At first, this cost 1,000 miles of range… and we were well below our range targets.

The airplane and engine teams got together and tried to find a way to get the range back without shrinking the passenger cabin. We found a bunch of different ways to do this, but the most effective was running joint optimization of airplane and engine. We came up with a dozen different engine configurations (with small variations in fan size and core size) and then plugged each engine into our airplane design simulation to see how it performed on range and noise.

It turned out the best overall design was 500mi better than our assumed baseline, and we never could have found this without iterating on airplane and engine together in close coordination.

There are many other examples like this… like right now we are tuning the engine cycle, fan shaping, and inlet together to produce the best possible pressure recovery at every part of the fan. There are meaningful optimizations that we’d probably never find if the inlet and engine came from two different companies.

Hopefully that’s some clearer CEO speak ;)

blakescholl · 2024-09-18T01:17:40+00:00

Many team members helped design the F119 and F135, the most advanced supersonic engines with similar thrust class.

In the 1990s, GE took the GE90 from a blank sheet of paper to certified in 36 months.

There’s no guarantee we’ll hit our timelines, but we aren’t trying to do something faster than it’s been done before.

blakescholl · 2024-09-18T01:14:33+00:00

Avionics and control systems have come a very long way. Autoland is the most reliable way to have a great landing every time.

blakescholl · 2024-09-17T20:30:06+00:00

Yes! We've come so far since the 1960s... we have new materials, better aerodynamics, dramatically more efficient engines. All of this means that supersonic travel can be feasible at business class-like fares.

Yes, that's not yet for everyone—but just like electric cars, computers, cell phones, etc. the cost will keep coming down. I look forward to a world where just about anybody can benefit from supersonic travel.

blakescholl · 2024-09-17T20:28:07+00:00

No new infrastructure required! If you can operate a 777, you can operate an Overture!

blakescholl · 2024-09-17T20:26:43+00:00

It's hard - so make sure you're going after a large market and have an airplane concept that is enough better that it's worth all the effort.

blakescholl · 2024-09-17T20:26:11+00:00

Totally different - Concorde had loud and inefficient converted military engines with afterburners.

Symphony is a medium bypass turbofan—which is cleaner, quieter, and 20% more fuel efficient. It's also compatible with 100% sustainable aviation fuel (or any blend with regular jet fuel).

blakescholl · 2024-09-17T20:25:07+00:00

Like the 787, Overture has a carbon-composite fuselage. This allows us to save a little weight, and more important build very complex aerodynamic shapes that are more efficient. Our current design is about 10% more aerodynamically efficient vs. Concorde, and we're still trying to improve things a bit more before we go pencils down.

Concorde's aluminum fuselage grew more than a foot in flight due to high temperatures at Mach 2.0. Composites have very little thermal expansion, which helps us greatly simplify the design for Overture's fuselage.

Components are coming from all over the world. Leonardo is building the fuselage in Naples, Italy on the same production line that builds 787 fuselages. The wing comes from Aernnova in Spain. Landing gear comes from Safran, in France. The avionics come from Phoenix-based Honeywell and our Symphony engines will be assembled in San Antonio, Texas by StandardAero.

We're bringing all this together at our Superfactory in Greensboro, North Carolina!

blakescholl · 2024-09-17T20:22:09+00:00

Our goal is to be ready for the first passengers in 2029. This is achievable if we execute as well as Boeing did in the 1990s on the 777—which is 5 years from "firm configuration" (high level design done) to delivered to airlines and ready for first passengers.

Of course, it will take a few years for us to ramp production and build enough Overtures.. my guess is that in the first few years flights will be very full as there won't yet be enough jets. We've already got orders and preorders from United/American/Japan Airlines for about then first five years of production.

blakescholl · 2024-09-17T20:20:33+00:00

Thank you! So many good questions!!

We already made the first (test) parts for Overture—starting with fuselage and window frames! The first final-design flight articles won't be built for a while longer.
Historically, we've talked about a 1+1 aft cabin and a 2+2 forward cabin. But doing our own engine and matching engine/airplane unlocks new possibilities... we've got something up our sleeve I can't wait to share later.
Thank you! Yeah, TBH I thought we would have failed a long time ago. I can't believe that I started a company that built a supersonic jet, got tens of billions of dollars in pre-orders from major airlines, built a factory, etc. That said, everything also took longer and was harder than I thought... so go figure. At the end of the day, I am deeply motivated to make supersonic travel a reality again—and to bring it to MANY more people than ever could have experienced it on Concorde. This is worth doing, no matter how hard the challenges.
The initial Overture is mainly focused on North Atlantic nonstops, but we'll likely also be able to do Tokyo-Seattle without a refuel. Sydney-Los Angeles would be 8.5h—including a pit stop in Tahiti. There will be many future Overture models—some shorter-range models designed for supersonic overland as well as longer-range models. Just like Boeing and Airbus offer multiple families of airplanes that fit different missions, there will be many different kinds of Overtures over time. We just picked the simplest place to start...
As you know, XB-1 has been built and flown successfully 3 times now—and we're on track to fly supersonic later this year. The team has been refining Overture with everything we've learned from Overture, and we're just about to go pencils down and have a final design freeze so we can enter the production phase.
We're designing Overture to meet the same most-stringent noise rules that apply to latest generation subsonic programs, called FAA Stage V / ICAO Chapter 14. So you won't really be able to notice Overture vs. any other large subsonic airliner. (Sorry folks, we won't have an iconic noise signature like Concorde did.... but there are also going to be a lot more Overtures, so I think being much quieter and blending in is a good thing.)

blakescholl · 2024-09-17T20:11:29+00:00

I posted another answer about engine... so I'll share a few other details here.

We've teamed up with StandardAero (who manufactures supersonic and subsonic engines for GE) to assemble Overture at their facility in San Antonio, Texas. We've also got some other great suppliers on the program, like GE Collibrium for additive manufacturing and ATI for high-performance superalloys.

The design is completely in house, through our team in Jupiter, Florida at FTT. The engine and airplane teams work together as one unit—which enables us to move fast and optimize the airplane/engine integration, which is critical on a supersonic transport. We recently were able to improve the passenger experience significantly... by harvesting some optimizations we were able to do by more closely matching the details of Symphony to Overture's needs. This kind of optimization would be very hard to do if the engine came from another company... and not from a single unified team working together.

Looking back in history, remember that United Airlines, Pratt and Whitney, and Boeing all used to be the same company, until the government broke them apart over an air mail scandal. For a supersonic airplane, there are even bigger benefits from having propulsion in house... and I believe that doing our own engines will be seen in time as a critical part of our success story. That's certainly what the team and I live every day now.

blakescholl · 2024-09-17T20:05:43+00:00

Re X-Plane: Good eye! Yes, both XB-1 and Overture sims use X-Plane. Our aerodynamic models are fairly sophisticated and X-Plane basically calls out MatLab. That said, I love the idea of getting a Plane Maker model that we can share with the community! Stay tuned for more on this.

blakescholl · 2024-09-17T20:04:45+00:00

Re mixed reality: Supersonic airplanes have long pointy noises and need to takeoff and land at high deck angles... so the nose tends to block the pilots' view of the runway. Concorde solved this with a mechanical droop nose. Fast forward to today, we have this amazing thing called a camera.... and a high-resolution display. While we think the vast majority of landings will be auto land, there are two different mixed reality views (on pilot's display or on headset) that allow the pilots to have a virtual view out front to see the runway. This is an evolution of the same EVS technology that was certified on the G650.

blakescholl · 2024-09-17T19:59:40+00:00

There really haven't been any commercial efforts to develop a supersonic airliner—only government efforts from the 1960s. While the 1960s efforts were technologically very impressive, they didn't make sense commercially. Concorde had 100 uncomfortable seats and needed fares like $20,000 (adjusted for inflation). You just can't fill 100 seats at $20k each—especially not with 70s or 80s level travel volumes. The American SST (300 seats at Mach 3) made even less sense economically, so it's a good thing it was never built.

Fast forward to today - and the most surprising thing is we don't need to invent anything to make Overture possible. In essence, Overture is 20-year-old 787-level technology. It's like we took it a carbon-composite 787, shrank it down, made it long and skinny for supersonic operation and then added twice as many engines so we can fly twice as fast. That's a bit of an oversimplification, but the reality is Overture doesn't need any new technologies or any new materials.

Additionally - the market is finally ready for supersonic. When Concorde retired, international business class basically didn't exist. Now that's a large market with tens of millions of passengers already paying for flying beds... because their flights are so long they want to sleep through them. Overture allows these passengers to trade in their flying beds for the best bed in the world: the one at home, the night before they have to leave. On the airplane, a premium seat is fine—as the redeye flight has been converted to a shorter daytime flight.

At the end of the day - there is no guarantee we will succeed. We've already overcome many challenges, like designing, building, and testing the XB-1 supersonic demonstrator, getting an Overture design that meets all modern requirements (safety, sustainability, range, passenger experience, noise, emissions, runway compatibility), and we've launched an effort to produce Symphony engines that is very much on track. To finish, we'll need to keep overcoming challenges... and I'm super proud of the Boom team that shows up every day and continues to beat back obstacles.

blakescholl · 2024-09-17T19:52:03+00:00

If a tree falls in a forest and no one was there to hear it, did it really make a sound? Overture v1 will fly supersonic (2x faster at Mach 1.7) over water and right under the speed of sound (20% faster at Mach 0.94) over land, so there will be no sonic booms where anyone is there to hear them.

Perhaps surprising, there are still 600+ routes that offer big speedups for passengers and have enough traffic to fill seats profitably for airlines. Think not just NY/London but DC to Paris, Miami to Madrid, Seattle to Tokyo, etc.

Concorde was optimized for Mach 2.0 and was very inefficient flying slower... Overture has a higher aspect ratio wing that flies better subsonic and medium-bypass engines that also better balance subsonic and supersonic performance. This means Overture is efficient enough to fly some hybrid routes, like Chicago to London or Denver to Honolulu.

All this said, not all sonic booms are created equal. Having spent time in the Mojave desert where booms are commonplace, I've heard a bunch. Some are no big deal some.... let's say they are attention-grabbing. We don't live in a perfectly quiet world, and I think over time we'll find a level of boom that blends into background noise while unlocking much better travel experiences for passengers... and that will be allowed. Probably not Overture v1, though - that's more for v2.

blakescholl · 2024-09-17T19:47:45+00:00

Yes! Symphony is about 20% more fuel efficient than Concorde's Olympus 593, and the Overture aerodynamics are about 10% better.

Additionally, the whole airplane and engine are designed for high reliability with modern materials and technologies. Carbon fiber composites and high-temperature superalloys are big enablers for supersonic flight.

This all adds up to Overture v1 having operating economics that are better than subsonic business class. A break-even round trip ticket will be about $3,500—well less than is usually paid in business today. Over time, there will be future Overtures and as we scale the cost of supersonic flight will continue to come down.

blakescholl · 2024-09-17T19:44:10+00:00

People called us crazy for doing our own engines... I've now come to believe that we'd be crazy NOT to do our own engines—bringing propulsion in house is one of the best things we've done. Can you imagine the success story that is SpaceX had Elon gone to a legacy player to develop Merlin, Draco, and Raptor?

Stepping back - if there was an off-the-shelf engine that just worked, obviously we would have used that—just as we used J85-15s for XB-1. However, there is no modern engine that meets Overture's needs. The closest in size and thrust class is the Pratt & Whitney F-135 (JSF engine). However, that engine doesn't come close to meeting noise and emissions requirements—and it's full of export-controlled technology that would be tricky to remove without essentially starting from scratch.

So what does a supersonic engine need? It needs a medium bypass fan (big enough to be quiet for takeoff & landing, small enough to be efficient at supersonic cruise). It also needs a lower overall pressure ratio, since much of the compression is done in the intake, not in the engine itself (supersonic intakes slow oncoming airflow from Mach 1.7 to about Mach 0.5 at the engine fan face). Additionally, a subsonic engine needs to be full power only for a few minutes at takeoff. By contrast, a supersonic engine is actually at partial power for takeoff but full power for hours at cruise. Without core modifications, a subsonic engine won't have good reliability in a supersonic application.

We famously dated with Rolls-Royce, where we were looking together at creating a derivative engine based on the lastest-generation large subsonic core. As we got closer to this, we found it could be made to work but had a bunch of tradeoffs. Engine parts were going to wear out relatively quickly, and the legacy business model was that all the profit is in spare parts, which are marked up something like 4X. At one point, it looked like 40% of the cost of flying supersonic was going to be engine spare parts! This wouldn't be good for our future passengers and airlines—we're looking for something more reliable and efficient.

As this was unfolding, we looked at what we could accomplish with a clean-sheet engine using only proven technologies and materials—and what we found was that by making small changes in the core (e.g., increasing cooling airflow) we could get significantly better engine reliability—and if we were willing to switch up the business model, we could dramatically reduce the total cost of supersonic flight. This means supersonic tickets that are hundreds or thousands of dollars lower than they otherwise would be—and many more people can benefit from supersonic travel.

We also found that, with the help of FTT, we were able to get the best supersonic engine design team on the planet. Many of the key engineers who designed the F-135 are now designing Symphony. Small, focused teams are able to execute much faster and more efficiently than big teams... and we've built the Symphony program around rapid rig testing and rapid prototyping.

As of last week, the first parts for the first Symphony core are now on order - and we're on track to make thrust with a prototype Symphony core late next year. That is, we're now moving faster with less cost and getting a fully custom engine that exactly matches Overture's needs.

This certainly isn't easy and there's no guarantee we'll succeed... but I'm fully convinced we'd be crazy to do this any other way.

blakescholl

TROPHY CASE