Air taxi trailblazer

Tom Prevot, air taxi product lead, Joby Aviation

Click at right to open this story’s Knowledge Guide entries.

Click star at right to open Knowledge Guide.

Positions: Since January 2021, air taxi product lead at Joby, in charge of developing Joby’s planned air taxi service, including the smartphone app through which passengers would book rides. Director of airspace systems at Uber Elevate, 2017-2021, where he led development of the cloud services and simulation tools for Uber’s planned air taxi service, sold to Joby in late 2020. Held a variety of positions at NASA's Ames Research Center in California 1996-2017, including head of the Airspace Operations Lab that evaluates how future mobility concepts, including drones and air taxis, would fit into the national airspace. Technical officer in the German Air Force, 1985-1995.
Notable: Came to the U.S. in 1996 after receiving a postdoctoral research scholarship from the National Research Council. At NASA Ames, invented the MACS (Multi-Aircraft Control System) software that simulates air traffic situations, including inclement weather and simultaneous remote piloting of multiple drones. Recipient of two NASA Software of the Year awards: the first in 2017 for the TSAS (Terminal Sequencing and Spacing) software for air traffic control; the second in 2019 for the UAS Traffic Management Services software.
Age: 56
Residence: San Jose, California
Education: Diploma (equivalent to a combined bachelor's and master's degree) and Ph.D., both in aeronautical and astronautical engineering, from Munich University of the German Armed Forces, in 1990 and 1995.

In one way or another, Tom Prevot has been preparing for the emerging advanced air mobility market his entire career. After nearly 20 years at NASA simulating how the U.S. airspace could accommodate new aircraft designs, plus four years at Uber’s AAM division Elevate, the dual German-U.S. citizen is now helping bring electric vertical takeoff and landing aircraft, eVTOLs, to market as air taxi product lead at Joby Aviation. The California company that purchased Uber Elevate in 2020 wants to be the first to ferry passengers around U.S. cities, starting in 2024. Along with earning FAA certification, Joby’s ambitious goal requires developing flight routes and building an intuitive smartphone app through which passengers would book rides. I led an Aerospace America and audience Q&A with Prevot at AIAA’s SciTech Forum in January. We met in “the HUB,” an event area of the exhibit hall at each forum. I’ve condensed and edited the discussion for print. 

Hofacker: Just this morning before our interview, Joby announced FAA approval to begin test flights with a second S4 prototype. What does this mean for the 2024 target?

A: What it means is we can fly more, we can produce more data, we can support our certification efforts more than we used to with just one aircraft. We’re all about executing.

Hofacker: There’s certainly high hopes for the advanced air mobility market, with projections of billions of dollars by 2030. How big do you think this market has the potential to be?

A: I’m not going to make any number projections or anything; I don’t have my crystal ball with me to do it. But other people have done that. Just like you said, there are different models out there. People are talking about billions of dollars in the mid-2030s. I think there’s a huge demand for people to relieve some of the congestion in cities, to get towards much more sustainable means of transportation than what we have today, and so we think there’s a huge opportunity to meet that demand with aircraft that are quieter, that are zero emissions while we operate them. 

Hofacker: In investor materials, Joby has described 300 aircraft flying about 20 routes a day in Los Angeles alone, so that gives us a sense of the scale.

A: The Joby vision of saving a billion people an hour a day will require lots of aircraft and lots of operations, and we do believe that the demand is there. Obviously, that’s not where we’re going to start. We’re going to start with a few flights, operate them in the current environment so that people can really experience the difference between aircraft like ours and what you would use today to do these flights, like a helicopter, how much quieter it is. It also gives the communities just the first sense of what these aircraft are, and then we do believe that’s going to even increase the demand for it from the models that we’ve seen. There was a lot of demand modeling done, including back at Uber, that is promising.

Hofacker: I’ve noticed that among AAM companies there tend to be two buckets: those that want to be first to market, like Joby, and those that want to wait for the market to mature. Why does Joby think the first category is the right strategy? 

A: I believe there’s not going to be a second category without the first one. It’s an opportunity for us also to kind of be the pathfinder, to make sure this market is going to happen at all and then to get the aircraft out there. If nobody took the step of leading the way into the market, we probably wouldn’t get anywhere. Think about where would be the electric car market without Tesla. Where would ride-sharing be without Uber? We want to make this market real; somebody has to lead the way, and I feel like we are in the best position to do that because our aircraft is getting ready.

Hofacker: Uber has such great brand awareness that people say, “I’m going to Uber.” Is that what Joby wants — for us to one day say, “I’m going to Joby?”

A: Well, I wouldn’t mind. Sounds pretty good.

Hofacker: I can imagine a scenario where I’m late for my air taxi ride because I have to take an elevator up to a rooftop vertiport. How are you thinking about those logistic challenges?

A: That’s a very good question and that’s a key component that we’re right now digging into. We do have a specific product manager for our passengers and riders, and some of us bring the experience from Uber with us. At Uber, we ran a very similar pilot in New York City, where we had cars pick people up in downtown Manhattan, we pooled several people together to a heliport, flew them over to JFK International Airport, and then had other cars pick them up on the other end too. And some of the first things that you learn are that you’ve got to deal with all the things that can go wrong. Predicting arrival times in downtown Manhattan is difficult with cars, so you got to build in the right buffers, the right trade-offs between not waiting long for your helicopter, but just long enough so that you can have a little bit of extra buffer in there. Then the wayfinding along the way is also something that’s extremely important, so you’ve got to design the app right, that at the right time you get the right context — “Go here, go there, go there, go to this location” — so that you can find your next leg of the trip. This part of the passenger experience is a very critical element that we see and are working on today to try to get right.

Hofacker: Give us a general sense of the app — is it going to be similar to Uber’s, I plug in my location and push a button to book my ride? 

A: It will be similar. You will be able to book the entire trip through either the Uber app or the Joby app. But you can imagine the Joby app is a little more aviation-focused and a little more leaning into the aircraft and that experience, given that people are probably more coming from that direction. Both will give you the options to book the entire flight. That’s at least how we lay it out. And both of them should be, the Joby app as well, simple to navigate. And we do a lot of product testing along the way. We don’t have to wait for our aircraft to be certified to do this. We can work with traditional aircraft today and kind of get into this passenger and rider experience and build out the product flow. And we do have an initial app that we use internally.

Hofacker: Why did Joby decide to go with on-demand services versus scheduled flights?

A: Looking at the Uber trip data initially and how people travel around the cities, it basically tells you that there are certain patterns, but there’s also many different elements that come into play that help people decide what they want to do at any given time and when. If there’s a big football game somewhere, people have a different travel pattern than if there’s a vacation timeline. So in order to serve as many people as possible and meet their needs, we feel like it’s much better to have a flexible service, on-demand service than a scheduled service that runs the same every day. We want to utilize our aircraft in the most efficient way. That way we can have as many people on board to keep the prices at a reasonable level. So it feels like the on-demand model is a lot akin to what people do in the city urban air taxi use cases. I mean, who orders a taxi every day at the same time?

Hofacker: How do you think that calculus might change as you move out into rural areas or longer trips rather than just short inner-city hops?

A: One of the first things is you’re going to be able to connect more areas into the cities, right? I think that there’s been some statistics done way back that show traditionally, people live about 30 minutes from where they work and that is independent of the means of transportation. So when all you had was to walk, you would live much, much closer to the city than if you could drive or if you had some other form of transit. So perhaps with having an aircraft that allows you to get there even faster, people might be able to spread out even more and then you might be able to connect those communities that are sort of underserved today with these aircraft into the larger picture as well.

Hofacker: Since the covid pandemic, we all feel a little differently now about being in close quarters. Is Joby still confident in the ride-sharing model?

A: We can try and keep things very, very safe, and we will keep things very safe. We control who gets on the aircraft. We can screen folks. It’s still a small aircraft; there’s a maximum of four passengers, so it’s a much more controlled environment, I would say, than if you go into a larger airliner in some sense. But still, we can take the appropriate safety measures so that people feel comfortable boarding the aircraft. It looks like ride-sharing also is coming back. We will have to establish the trust that we need from our passengers, but I think that we will, and I feel like it’s a pretty decent model still for people to travel around. I’m hopeful it’ll stay that way.

Hofacker: That gets to this larger idea of public acceptance. How is Joby thinking about introducing the public to this?

A: One of the things that’s important is experiencing the aircraft, and we’ve already published a few elements where you can see the aircraft fly, you can hear the aircraft noise compared to other aircraft in flyovers. None of this is a real replacement of actually seeing it and I’m sure, in the very near future, we will also be flying where it might be a little more accessible to the public. And then over time, we want to really have people understand that this is different from what you typically see. It’s not very noisy; even during takeoff and landing, you’ll barely hear it when it’s above you. It’s got to be friendly. This idea didn’t get much traction in the company, but I always felt like maybe you could have some communities design their own aircraft; take some ownership, get it really nicely integrated into your daily life, essentially. 

Hofacker: You mention noise, but I’ve noticed that Joby and other AAM companies are pretty secretive on how that quiet flight is achieved. Is that because you expect noise is a make-or-break element for AAM?

A: I do think so. The Joby aircraft has been designed from the very beginning, literally, with noise in mind. The advantage of distributed electric propulsion that you have is you can control multiple props on the aircraft at very different speeds. You don’t have these high tip speeds that you have with helicopters, for example. So it’s very much designed around this noise profile, and the measurements that we’re taking are proving that is working out. But I feel like that’s probably one of the biggest make or breaks. I mean, when I’m at home and I hear certain aircraft at night, it’s disturbing.

Hofacker: I’ve always wondered how likely it is that people on the ground would hear the aircraft overhead, especially in the middle of a busy city where there are buses and cars passing by.

A: It’s very unlikely. Noise profile is going to fit in and the sound level is probably less than the cars you hear.

Audience member 1: What would you see as the potential obstacles in terms of getting the certification with the FAA?

A: We have the certification basis that we’ve agreed upon with the FAA through the G-1. There’s definitely a lot of additional steps on the matters of compliance that have to be taken, but I feel like it is at the execution level right now, where we know what we have to do. It’s going to be a lot of work, but that’s one of our main priorities to do that. I can’t really point to any single main obstacle that I would see right now.

Audience member 2: For me and for a lot of my friends who are also women, personal safety is a big issue when it comes to taking a taxi or an Uber. With air taxis, you won’t have the option to say, “Pull over, let me out here.” So what steps are you going to take?

A: The first thing is that we are only going to be using commercial pilots, highly trained pilots. They will have undergone vast safety checks, background checks and everything you need to do there. So I would say, not quite the same amount of people who could be in charge of your vehicle compared to an Uber. We’re also going to do a reasonable amount of safety checks on the passengers. I don’t know exactly what the details are going to be, but we’re going to figure out what the right level of checks is. Certainly things like checking against the No Fly List, other things are on the table. It’s questionable if you want to go to a TSA-level check there, but we’ll do whatever we can to keep people safe. 

Audience member 3: Do you have any estimates on how much weather will affect your ability to operate?

A: Initially, more than we hope than at later stages. When we’re going to start operating, we’re going to be primarily operating in visual conditions and nicer weather. It is a new aircraft, so you kind of have to feel your way into it a little more. It’s also a question then of, again, acceptability. For people who’ve flown the smaller aircraft in really bad weather, that’s not very comfortable initially. We will follow up our initial certification with an IFR [instrument flight rules] as well, so that if we get into a situation, we could continue to fly where weather gets bad. But we’re probably going to be very conservative, initially, to stay out of difficult weather situations and then build up that capability over time.

Audience member 4: What are the biggest obstacles and even the biggest opportunities in moving from piloted aircraft to autonomous flying?

A: There’s a number of elements. The main thing is having the pilot on board, the pilot can do the see-and-avoid tasks. One of the primary tasks of the pilot is they look out for the aircraft, they look out during takeoff and landing, depending on what the minima are. We kind of know what the regulations are if you do that for the larger airspace and larger UASs, and it requires a lot of additional equipment, radars, and detect-and-avoid equipment. It will also then require the large separation standards that you need between aircraft, and so there has to be some more work to be done in really figuring out how can we take out the pilots safely and maintain a higher throughput and what’s going to replace the pilot’s decision making and eyeballs in the aircraft. Maybe some of the small UASs can lead the way with some of the technologies that are being developed there. We definitely want to get to autonomous flights eventually, but it would be a pretty high risk to try to do that from the get-go.

Audience member 5: Two questions: The first one is on the cost model, and the second is about the safety of the aircraft itself. For example, FAA certified the 737 MAX, but you had these crashes. Can you talk about the safety measures taken?

A: The goal is to start operating about at a similar price point as you would pay for an Uber Black and then get it down over time to an Uber X-type price for the aircraft. According to our models, that’s seems feasible and economical. On the safety, there’s a number of different things that we do. First of all, there’s a lot of redundancy on the aircraft. There are independent battery packs. Each one of the rotors is being driven by two independent batteries so if one of the rotors go out, one on the opposite side would be turned off and we can still continue to fly, we can still continue to go vertical. There’s a lot of redundancy that’s built in. So those are the two main concerns with safety and noise on the vehicle. There’s more information on the details also on our website. You can look at some of the diagrams of the aircraft, how that is being built in. We are trying to get to a similar level of safety as air carriers. 

Air taxi trailblazer