 Yeah, everyone welcome back. Thanks for those of you who stay with us after the pedals lecture. Those of you who are just joining us, this is a panel session following Dr. Hansman's talk about more electric and more automated aircraft and some of the innovation and exciting opportunities happening here. So this panel, Professor Hansman has been joined by several Purdue faculty members that don't reduce themselves, but we tried to pick a panel that has expertise in airports, air traffic management, aerodynamics and aircraft design, human automation interfaces, and all of them know things in multiple areas here to help round out the discussion. So what I get to do is introduce our moderator for today. The moderator is Brandon Sells. Brandon is a PhD candidate and a research assistant in the School of Aeronautics and Astronautics here at Purdue. Here is MS in Aeronautics and Astronautics from us here at Purdue and his BS in mechanical engineering with an aerospace concentration at North Carolina ANT. Recently Brandon has been developing and employing modeling approaches to investigate important operational limits that might hinder future use of urban and region air mobility and is also looking at ways to examine important characteristics of electric and highly automated aircraft with the region that they may operate in. So with that I'll turn it over to you, Brandon. Great, thank you. Welcome everyone. We definitely appreciate you sticking with us and right now I'm actually gonna introduce the panel and so you can hear from their great voices. I'm gonna start from the farthest and work my way inward. We're gonna start with Dr. Hubbard. Dr. Hubbard is an associate professor in the School of Aviation and Transportation Technology. She is a licensed engineer and has done research in transportation planning and operations including airport operations and safety. Please welcome her. Next we have Dr. Bear Caldwell. Dr. Bear Caldwell is a professor of industrial engineering and Aeronautics and Astronautics by courtesy at Purdue. His research team is the group performance environments research grouper laboratory. A grouper examines and improves how people get, share and use information while in settings including aviation, critical incidents, response, healthcare and space flight operations. Please welcome Dr. Culpe. Dr. Hansen, welcome again. For those that didn't make the lecture before you missed a great treat. But Dr. Hansen is the T. Wilson Professor of Aeronautics and Astronautics at MIT where he is the director of the MIT International Center for Air Transportation. He conducts research in the application of information technology and operational aerospace systems. He has over 6,000 hours of pilot and command, time in airplanes, helicopters and sail planes, including meteorological production and engineering flight, test experience. Please welcome him. Next we have Dr. Leefer Lee Sin and he is an assistant professor with the School of Aeronautics and Astronautics at Purdue. His research is focused on simulation based design optimization of aerospace systems such as aircraft using surrogate modeling methods. Please welcome Dr. Lee Sin. And finally we have Dr. Dimfin Sung, he is a professor of aeronautics and astronautics. Before joining Purdue, he was an associate scientist with University of California Santa Cruz at NASA Ames Research Center. Professor Sun's research interests include distributed control and optimization, cyber physical systems, unmanned aerial vehicle systems, air traffic control, air transportation and intelligent transportation systems. Please welcome Dr. Sun. Great. So the format for today, we're going to start with some questions, but definitely feel free to find the mic in the audience so that your questions can be heard. I'm going to start you guys off just in case you need a minute to find your questions. But panel, feel free to jump in at any time. So our first question today is, what are some examples of electric aircraft and automated aircraft that have recently made their way into use in operations? So I would start. So from electric aircraft, the only electric aircraft that I know that's actually certified, it's only certified in the in Europe is the Pipstroll training aircraft. So it's a two seat training aircraft. Everything else is in development. Okay. In terms of automation. Okay. Well, let me say that's on aircraft. If you want to go to UAVs, we, you know, there's a lot of UAVs that are out there. Okay, right. Understood. All right. If you want to go to aircraft and then highly automated aircraft, we, you know, if going all the way back to the Airbus A320, almost every commercial transport airplane now is a fly by wire airplane that is effectively automated, except for taxing out and taxing in. And by the way, we can do that. They just have something for the pilots to do. Of course. And even for like humans being able to accept that, that may be a concern. Correct. Well, this whole question is, what is, what is the willingness of the traveling public to get in a, in a vehicle when there's not a path there. So if you actually look at it from a safety standpoint, pilots probably, there's some evidence of pilots cause more trouble than they help. Okay. But the problem is we don't actually, so we have a lot of accidents that occurred due to pilot error. However, we don't get all the accidents that are saved because of pilot saves. So we don't really know the answer to that. But at some point, we're going to get to the point where we'll fully automate. It's going to probably come in through cargo first. But when will people be willing to get on there? And I think it's, it's a matter of trust. So there's the assumption that the pilot in the front is the first to the scene of the accident, right? So they're going to make a decision that is, has the highest probability of success. That's the social assumption. So, but I think we'll get there eventually, you know, slowly when it really matters. Right. Now, to add on to that, when you think about pilots integrating to the technology, is there a human factors question that comes into play? And I don't know, Professor Caldwell, if you want to take that question for you there? Well, I think the whole list of human factors questions that come into play all the way from where in the design stage do engineers recognize the range of human variability in understanding in processing the situation? I always get frustrated when I hear designers talking about taking the human out of the loop, because the last time I checked, all of the designers were humans as well. And so they're subject to many of the same biases in attentions, considerations that they are and even projections that they're afraid that the pilots are. So I think just that understanding that you are designing for people who may or may not see the world the way you do is one of the most crucial human factors issues there. And another one by analogy, I have a series of sports cars because I like that stuff. And it's really, really nice that in my newer car, it has ABS. And I really like ABS. It's wonderful. And the computer coordinated steering and torque control is wonderful. It's fantastic. I love the idea that maybe I can turn it off sometimes when I'm feeling salty, okay? What I really, really worry about very badly is the moment where the ABS says, I can't do this anymore. And what is that failure mode? They fail over to the human. Well, at that point, if the ABS says I can't handle it, and they tell me with a quarter second that I need to do something, I can't do that. That is an unreasonable and unstable human in the loop control problem. Does the rest of the panel want to comment? Or have any future examples on electric aircraft that they'd like to add? I can chime in for a little bit for like a human involved in the system. You have pilot and we also have aircraft controllers, who are also human beings. And also if you fly an airplane with a pilot, like the pilot wants to talk to a person, right? Instead of like you call customer service, automate the voice system, we don't like it. Most people don't like it, right? So we still have human controllers. And we are trying to like develop the students supporting tours to help ease the work of traffic controllers. But still, we still have those human factors in terms of the air traffic control systems. Let me throw out a challenge. Should we should we get rid of the high altitude air traffic controllers and automate them out of the system? I would vote no, which I would like to keep human in a loop. See, I think we should, I think we should get rid of the high altitude. Because I think the air traffic control, if for like, to say the North Atlantic or the South Pacific, there's plenty of space there. I have on board equipment. I want someone to call when I have a problem, but I don't think I need to be talking to them all the time, right? So so I, you know, we spend about $300 an hour for every flight hour of air traffic control services. And I'm not sure we need it with the current technology. Go ahead and jump in, Dr. Leeson, if you like. Yeah, I can jump in here, maybe from the kind of viewpoint of the aircraft designer, who's also a person. So first of all, I want to thank Professor Hansman for his talk. It was really good. And I'm really happy to be on this panel. And I think this new class of aircraft is really exciting and interesting from the perspective of vehicle design. And you kind of talked about that a little bit, because you have these new technologies, these new operations kind of open up the design space. And so I think it's really interesting for our students and faculty here to kind of address these things. And also it's an opportunity to work with the industry on these things. So where there are a lot of new things happening. So from the designer perspective is that now you have this new kind of new designs or new concepts. And you kind of have to go away from historical kind of data and kind of statistical based designs. And you're going to start to have to use physics based modeling and maybe optimization as well. And I think there's tremendous opportunity here kind of to leverage those things to really design these things. And because these are really complex systems with a lot of design parameters, especially when you kind of open it up like you talked about. So we're going to have to leverage these physics based models as well as optimization tools. And the good thing about this is there's been a lot of development in the recent history. So there's a lot of open source tools that can do kind of aircraft design using physics. And having those tools, we can use them to kind of evaluate and kind of compare these different concepts. So he showed a lot of concepts today. So I thought that was very interesting. And for example, if you're doing initial sizing, you know, for your those are going to take aircraft design class next semester, initial sizing that you can use these low fatality physics based models. They may be less accurate than the high fatality ones, but they're really fast. So you can kind of explore a lot of different concepts really quickly. And if you need added confidence, then you can resort to the high fatality tools as well. They are really long to evaluate. But so what I want to say here, there are ways to come to combine them and they're like these multi-fatality methods. You can create these surrogate models. And with these surrogates, you can kind of try to simultaneously optimize the vehicle shape, the vehicle parameters with respect to all these different constraints, because there are going to be a lot of constraints within the airspace. That's what I wanted to say. Great. I definitely appreciate that. And something that comes to mind are a lot of the technical challenges that we face moving forward, especially enabling electric aircraft. So Dr. Hubbard, I want to know your thoughts on those technical challenges and you know, where do you think we should be looking at to put research dollars towards? Sure. Well, I actually come to it from the airport's perspective. So I come to it from the infrastructure and really a big concern of mine is integrating the new systems with the existing systems that we have, the transportation systems, the community impacts. And so actually I'm going to leave a lot of technical stuff to you all. But I do think that that's something that's challenging. Right now, FAA Office of Airports has done interim guidance on the kinds of infrastructure that we will need for vertiports. Certainly the uncertainty is we don't know what those aircraft are going to look like. That makes it really hard for us. And one other comment is a lot of historically, if we're talking about the advanced air mobility model, a lot of the systems for the ground with the heliports have typically been licensed at the state level. And so that's kind of, we have a lot of policy issues that really haven't been addressed yet. So I guess some of those issues, those policy issues, those regulatory issues, those are things that will need to be sorted out as we move forward. And honestly, in some cases from an airport's perspective, that's a pretty big deal. One other comment from a technical standpoint, sustainability came up. And that's a really huge issue. And actually that's a big driver for advanced integration of technology at airports because airports are very concerned about their sustainability footprint. When we talk about sustainability at airports, one thing to note is we're not just looking at environmental sustainability, which is critically important. But we also look at the three, sort of the three pillars of sustainability, which are environmental as well as economic. And so what's the sort of economic footprint and how our infrastructure can support the community. And then the third pillar would be the social or the community impact. So again, we have kind of a probably a more broad based perspective than some of the really detailed things that you all are looking at, which are of course critical. But that's kind of where I come in at the airport's piece. Because especially this come to mind where you think about these vehicles that need to use the infrastructure. And so depending on your configuration and depending on your metropolitan, it could lead to a certain configuration that you may need. And again, I just want to remind the audience that if you do have a question, feel free to find us. And I don't know where the microphones are, but I'm sure someone can help us with that. Another question that I have, if we're looking at introducing new technologies into a safety conscious, highly regulated domain like aviation, it can present a lot of challenges. And so from your expertise, you know what trends give us the most concerns on this on the safety side? I think that that the when we're trying to certify things for which we don't don't have an existence proof, we don't have a current method, I would say the when we talked about the thermal runaway of the batteries, we can do that. The solutions we have now are very heavy. So that's going to be hard. The all these new configurations, the tilt rotors and whatever. They're not airplanes. They're not helicopters. They're sort of like the v 22 or the six and so they're they're kind of in there. But we don't have quite the same rules. And fundamentally, you have to look at what the failure modes are. So the the the thermal runaway is a problem that's well identified. The other one I mentioned is the energy density on a normal airplane commercial flight. We need to guarantee the amount of gas I need to take is dependent on what the weather is and what my diversion requirements are whatever. So I know how much gas I need to take. If I do that same calculation, I don't actually know what that transfers to on my battery. Okay, because it's not reliable. So there needs to be a solution for what the battery energy dispatch condition is. That's an open item. And then all of these airplanes have complicated flight control systems. Okay. So if you're in a fly by wire flight control system, and that way we think about this is if it fails and it's critical, it has to it can't fail with a probability of greater than 10 to the minus 9th or 7th or 8th depending on the class of the airplane. So what that means is that I have to have redundancy in the system. Okay. So I have to have and what what has to be redundant? Well, I have to have at least two actuators because if an critical actuator fails, did that that's why you saw so many rotors on the on the helicopter. Okay. But I also have to have redundant sensors. So and by the way, sensors are a problem because it how many sensors are enough? Well, two sensors, if I have two sensors and one breaks, which one is broken? So I don't know the answer. So typically I have to be triply redundant. Oh, by the way, now I have to have the computer could fry. Okay. So now I have to be redundant on the computers. Maybe I can get by with two. I don't know. Okay. Maybe two, maybe three. Oh, by the way, the data bus. Okay. I need to I need to have the wiring. And by the way, if the rotor goes out and cuts the wire, I can't cut all the systems. So I have to run wires in different parts of the airplane. Okay. Oh, I forgot about the software. Okay. Okay. So so in in, you know, how do we prove the software not there? So now, by the way, this is not an this is not a new technology. We do this on fly by wire airplanes. It's incredibly expensive. I think there's a lot of motion on making that more efficient and cheaper. And so that's a place where the technology is there. The processors are smaller. The sensors are smaller. The we can reuse software and things like that. So I think you'll see the Costco down there. But it has to be done right. And these are complicated systems. So how do I check them and certify them as there? So so I, I think it will be there, but it will be hard. So what let me follow up on that because I've been spending a lot of my time recently looking at low altitude operations and lots of discussions about we're going to have these automated systems and taxis and Uber eats over or whatever you're going to call it, right? And everybody is using the low altitude space. You can't get to transcontinental high altitude until you transit low out low altitude. You can't get to space in what until you transit low altitude. So imagine trying to deal with all of these things in a local airspace where someone is saying, yeah, but that's where my market is. So I want to I want to have lots of things in the L.A. Basin and I want to be able to dial up to get my delivery in 25 minutes. I want to get something from Port of L.A. in 20 minutes. I've also got dozens of commercial airliners. I've got everything else going on. Oh, by the way, there's also traffic helicopters and med flights and all that. I really have a lot of worry about how all of those operations are going to interconnect, interoperate and intercommunicate in these spaces. And I haven't even talked about an executive that might buy one of these companies and decide to completely redo the operations model and fire half the employees. Oh, no, that would never happen. Yeah. So I was wondering about what does this mean for EV tall aircraft, for example, like Joby and and whisk with these issues, these failure modes that you mentioned, as opposed to having an East all aircraft that maybe is less prone to those things. I mean, I think all of the airplanes will have to go through that process and do the safety analysis in whatever. I think that the more non traditional, you know, that's why if you look at the Joby airplanes, you know, what happens when one of the actuators gets stuck 50% of the way, right? So you have to they're you've just introducing new sort of failure mode. So there is there is elegance and simplicity of design, which is to minimize that. So but but I think it'll I think they're solvable. They just have to be worked and there's a process there. One of the things that got added into this NPRM is the ability to deal with the total power system. So if you look at the Joby or a lot of these airplanes, they they've been designed so that there's enough redundancy of one system goes out, they can still fly. Many of these things, if you have a total power failure, become a brick, right? And so that's actually in the regulation that it has to be survivable. So you'll probably have a ballistic parachute on that airplane. But those only work for higher altitude. So you have to design it. So the crash is survivable. Okay. Yeah. So I mean, it'll I don't know. I mean, it'll it'll be interesting how they come up with it. They're very complex design choices that need to be made. And forward with that, I think we have a couple of questions, three questions. We can start with one in the back. Feel free. Thank you guys for being a part of this panel to answer our questions. Could you stand up for us? Can we see? Thank you. I'd like to jump back a bit to the overall topic of how in in the electrification and automation of of automated aircrafts, like there's a lot that needs to be processed, right? So do you see semiconductors as a plateau for this processing? And if so, how what are ways to work around that? Do you guys need clarification for the question? Let me start and then you might. I mean, I think we are done, done, may have a comment. I think we have enough processing power to do it right now. OK, so I don't I don't see that as the limiting technology, right? I think in some future applications where people are doing more autonomy and whatever, but part of the reason why we still have humans doing the supervisory control is for really subtle A.I. type applications that would require a huge processing. We're just not there. And by the way, we don't know how to make sure that that that neural net is right. OK, so it's very hard for the certification agencies to actually approve nondeterministic software. So it's actually much easier for them to say when when the problem gets to this class, call the operation center and bring in a human. Right. So that's why I think it's going to become a supervisory control system where the humans will be there, but they will be there for the value added parts of the human. So they won't be doing. The groundwork, you know, most commercial airplanes now, the pilot just sit there with their arms fold and eat their crew meals and try not to sleep. Right. Thank you. Yeah, I agree. So I in terms of the hardware, I really don't see like much difference as compared to our current aircraft in terms of these electric craft. The major kind of challenge might be like as John mentioned, there is going to be some software and particularly nowadays you have artificial intelligence. I believe that there will be a core part in terms of autonomous vehicles, autonomous aircraft, how to certify the functional AI. I think that's going to be another way to think of it is we will only approve what we can. By the way, it's the same thing on the safety part. We'll only approve or only design to what we can do with confidence with the processors we know we can buy. So if you come up with a new processor, right, which is significantly better, that will open up the design space of what we will do. But it's not going to limit it. Same thing on the safety case. So, you know, when, you know, when you're worried about all of these other operations, they're simply going to say, well, you know what, you guys can't fly there because there's a commercial airplane and we're not going to put any risk to the commercial airplane. So there is a, it's more a safety limitation, you know, is the sort of way to think of it. Yeah. So I'm not really as worried about the on board flops as the bandwidth for comms between everybody. 5G is wouldn't be enough for the projections for LA or New York or Dallas Metro. Hartzfield would be a nightmare. So we have to think about not just what everybody does on their own, but at what rate can you update all of the onboard processors with all the state information that they're generating and then sharing with each other about very local phenomena? No, that's going to be the problem. And remember what's going to really, it isn't going to be the normal operation. It's going to be, you have to guarantee that you design it so when the loss of comm occurs, when I lose the link, that the system can't fall apart. Right. So it's got to be able to coast through a failure of some sort. And even with that, I'll take that question next. And even with that bandwidth, does that affect the like ground operations when you think about remote towers in locations that may not have the infrastructure to have their own tower? Is that also an effect that should be addressed with future technology? Yeah, it should. I mean, the good thing on the ground tower right if you're doing remote is it's probably a landline with alternate is to just take another route on the internet. The ones that are tend to be the toughest ones are the ground to air or air to air links that if you get saturated or you have a failure. So again, in all that safety analysis, someone has to think about that's a failure case. You do your failure modes and effects analysis. You then have to make sure you design the system so that when that happens, their plane may have to divert or may have to do something, but it can't crash. Right. Of course. We have a question in the front. Go ahead. Yeah. So I wanted to ask in 2009, there was kind of like a push for smaller jets, which are jet powered. And it ended up being like really expensive. And a lot of the jet projects for like smaller aircrafts didn't really take off because it was too expensive. So I looked at like these hybrid electric vehicles and also like electric and automated aircrafts. And we are putting like batteries on them, which are like really, really expensive technology as well. Will there be any concern that the technology that we're using is too expensive? So that's a good example. So so in that jet thing, the reason why they thought that it would be cheaper was that they thought that they were going to get the remember I use the word scale, they thought there were going to be lots and lots of cases. And so the prices go down when your production rates go up. Okay. For a variety of reasons, partly having to do with the economy, the economy tanked, they didn't get the scale that they thought that we're going to get in. And they were a little unrealistic on their on their assumptions. Okay. There's a lot of that same behavior going on here, which is a lot of the projections that people have have been on assumptions of scale. And that it's going to be really cheap and whatever. These airplanes are not going to be cheap. They're going to be good, and they're going to be safe. But particularly in the beginning, they're not going to be cheap. So the first markets are going to be markets that can justify the cost because you're doing something really beneficial. It may be Medevac. It may be Oregon. One of the big applications is Oregon delivery. So for beta, the big funding is this is the biggest organ delivery outfit. So they're going to fly organs. There's some advantages, you know, on some freight things. So again, these will be applications where the the performance justifies the high cost and then it'll get it'll get cheaper over time. But I think you're right on it's it's don't believe all the prices you read. All right, thank you. And I think we have another question in the front. So my question kind of pertains to risk and reliability assessment, especially for fully autonomous systems. Professor Caldwell, you mentioned that we have these theoretical low altitude systems like air taxis and delivery systems. Would these fully autonomous systems pose any additional challenges and the risk and reliability assessment of these systems over a more manual mechanical system and then kind of a follow up with that Professor Hansman, you mentioned in a con ops that we have an off board human operator. Would this neglect any of these additional challenges, if any? Well, I think one of the problems that you may be referring to is that we've got remotely piloted, unpiloted pilot in cockpit and trying to understand what are the risk profiles of what let's say intent communication between those different models. Just think about on our campus, we've got these little robots moving around. Fortunately, they're not very fast and they're not very bright and they're not likely to hurt us. And even if they completely break up, they're not going to fall on anybody. Okay. Being able to project what the risk profile is for one of these things flying around and we don't and you won't always know if it is remotely piloted or or completely autonomous. So it's very hard for someone else to figure out what the failover mode is for the other thing that you may see. And if you're trying to scan for five or 20 or 50 other things and trying to guess what they're likely to do, not being able to understand what their intent or the source of their intent is becomes a very difficult, deeply uncertain risk profile. I think that and again, I'm not sure I fully understood, but I'd say a couple of things. For the overflight, for the UAV overflights on the population, the ground, the reason why we do fly at 400 feet is because actually, let me step back. Right now, what we do is we segregate the unmanned airplanes from the manned airplanes by and large. So the low altitude is chosen because that's below the altitude that normal airplane operations are. So normally, you're not allowed to fly lower than 500 feet because you're too close to people. And that's what set the 400 foot cap for the UAVs. The limit of 54 pounds in a small UAV was actually set by the risk of passenger people on the ground. So under assumptions of some UAV randomly colliding and going, you know, we're actually involved in some of those calculations, you sort of figured out whether you're an acceptable level of safety. So it's considered, you can argue whether it's right. I think as we get to higher densities, I don't actually care about UAVs crashing into each other. Okay. So NASA had a big program of things to sort of solve that. You know, nobody's going to pay a lot of money, you know, the $200, $300 an hour to prevent UAVs from crashing. They're just going to take the risk. So they're either going to be good enough or they're not there. But lots of people, everybody cares about an airplane taking out a commercial airliner. So you're not going to be allowed to do something that would pose risk to that. So our job in terms of conceiving the system is to come up with systems by which we can guarantee everybody's safe enough so that commercial airplanes can stay safe. We're still allowed to operate. If he wants to deliver the donuts under the flight path to Indianapolis. Sorry, man. That mark is not available. So you're going to be restricted from so the places you can't you can't fly. So it's going to be a system that's designed and remember around the world, the FAA in the US, but the Airwardness Authority has access to the airspace. So you're going to have to convince them it's okay to operate your airplane in a safe way. So I think it's it's totally what we're thinking about. But I think there are things in process. I'm not sure I fully addressed your question. Yeah, I was mostly thinking towards the design and assessment conceptually when, you know, we have this system that is more fully autonomous. So it's mostly running on software and programs versus having a human in the loop, which with the conups that has a human on the ground, they can interject and take over when there's a fault in the program. But trying to predict the failure rates and the reliability of an autonomous system over more of a predominantly manual mechanical system. If there's any significant differences between the reliability and risk assessed with between fully autonomous and having a more manual. We've seen that even with the autonomy that we have in commercial airplanes today. When we went to the airbus and in Boeing sort of advanced cockpits, and Barry knows this, we created a whole new class of failures that were not anticipated or confusion with the part of the crew. I think we have to be ready for the same thing to happen as we inject these new systems in. This is typically in safety analysis is what we see as an entry into service blip. So we have to monitor and this is part of our safety thing is how do we monitor as we enter something into service to make sure it doesn't go really unsafe, right? So so I think it's a totally legitimate concern and we have to watch for that. It's worth thinking about that. And how much of it can we pick up ahead of time in simulation and design? That was thank you. That was mostly it is how could we actually simulate something like that effectively because it's like a newer technology. It's kind of shifting towards a more fully in their techniques. There's human and loop testing. You know, so you sort of do that. There's agent based models. There's, you know, so you you have to sort of think through what the risks are, right? And then figure out how you're going to address and quantify them. Thank you. I think we have another question in the back. So there's been a huge push for sustainability in the commercial aviation space sector. So I'm wondering and it seems like there's also been a push to return commercial I guess commercial travelers at supersonic speeds. I know like the company boom is specifically and then even pushing that past that to hypersonic. Well, there's a lot. There's a big sustainability hit when you do that. So how do you balance those two aspirations? I have a personal opinion, but yeah, I basically don't think that the supersonic is credible and I don't think it's particularly environmentally and ethically. So we've looked at it. I think it's you know, when the Concorde was flying, I think we didn't appreciate all the environmental impacts, but those airplanes are really dirty airplanes. And so you have to ask yourself, what is the what is the social value of having a really rich person get to their meeting faster and how much is it? And I think we now appreciate some of the environmental impacts. It's hard to justify going that far again for social defense for defense missions. Maybe there's something but for you know, having some really rich person prove how important they are by getting the meeting fast, I don't think we need to blow up the planet. Even even with potential advancements, with getting those potentially like more sustainable, it's just the the benefits now aren't worth exploring those options. It's totally it's only worth to explore as a research standpoint. Totally totally there, right? Because but you know, my hope would be what you would learn and thinking about that would apply across the system or generally to make the whole system better. But but I think you know, the the supersonic thing you know, and we can have a whole dialogue about supersonic in whatever. I won't you know, everything is a trade off on on cost and benefit. So what is the benefit I'm getting from this capability, supersonic capability? And what is the cost? And those are really expensive airplanes that would be hard to be safe enough to be safe, which have to get exemption on the noise footprint on take off, which have to get an exemption for the noise from the sonic boom, which would then fly at higher altitude where they have an higher impact into the ozone depletion effect, which burn five times the amount of fuel that you would have on a transporter plane to save two hours. It's just the trade to me just doesn't make it. Thank you. I think the cost of this like one flight one seat per flight for the Concorde was ten thousand dollars. I was actually telling Dan to say so we did an analysis 20 years ago or 15 years ago on supersonic business jets with Gulfstream. And we looked at the history of the Concorde when it was flying when the Concorde flew. I used to fly over New York all the time when the Concorde flew. It would fly one cycle a day. One of the mission routes was, you know, New York to London. So go over once and come back. So every time you flew over JFK, the Concorde, you'd see it was beautiful. You'd see it on the ground because it was sitting there because it sat on the ground most of the time. OK. Right. And then when we looked into it, I can't remember the sea load was like 60 passengers. We looked at how many people were willing to pay full fare to fly Boston to New York. It turns out it was about six a day. So there are people who need to want to be in New York in the morning, fly to London, have their meeting and be back for dinner. Right. But there's not a lot of them and they don't fly every day. So there's not a huge demand. One other thing on the supersonic airplanes is if you look at it from an airline standpoint, it's very hard to put together a network of supersonic airplanes that makes sense. So on most commercial airplanes we fly them, you know, between 14 and 16 hours a day. So we put together networks where the airplanes are busy. The problem of the supersonic airplane is it gets to, you know, let's just say you could fly to Tokyo. You get to Tokyo at a point when nobody wants to fly back so the airplane has to sit there. So it's hard to put together those networks. So they're, you know, like say they sound good. There are a few rich people who would buy them if you could make the airplanes. But I think from and they would really require a new engine technology to be credible. So in order to get there, it's it's a real push. I'm sorry to be so down on it, but it just, you know, when I think about the challenges we have in aviation, it's not where I would spend my buck. Thank you. So recently, you know, with the push for electrification and UAVs, that's really been at least what I've seen the main driver behind this urban air mobility movement. Why now? Why not with, you know, the helicopters of previous generations? And why not just make those helicopters autonomous? Why spend the time to develop all new vehicles? Jet packs. Where am I going with this? The urban air mobility movement is at least seventy five or eighty years old. There have been people talking about jet packs and personal mobility even before World War Two. The question was, was there a viable technology that could do that without you putting serious explosive hypergolic cryo on your back? OK, so, you know, and I don't want to do that. So I think the urban air mobility movement is basically sort of like Jules Verne saying let's go to the moon and then it taking another almost hundred years to say, oh, yeah, we know how to do that now. So the desires, I mean, that's what science fiction gives us is the ability to think about a future like the supersonic or something like that and say, OK, can we do that? How do we do this? Should we do this? I would say two other things. Well, one is science fiction. I mean, the Jetson car was always the right. OK, but there was a convergence of two things. One is the Uber effect, which is people suddenly realize there was a way to do on demand that was reliable. OK, so on demand mobility became a thing. But then the whole push for urban air mobility was really because of the limitations of the battery technology. So there really wasn't much. You know, you could build an airplane, but it only had a range of 25 miles. So what is the mission you could do at a 25 mile range that would make sense? And it turns out taxi cab rides are it, right? So so I think that was that pulled together in the people who who pushed that originally from NASA were really driven by looking for again, it was a technology push, looking for a mission, not a requirements pull. And I I said exactly the same thing at the time, which is, you know, if you're really if this is such a great market, why aren't people flying it today in helicopters? By the way, there was a time in the seventies when people did do helicopter missions. OK, but it it got run out by noise reasons and a series of accidents. Tell you one sort of anecdote that used to be able to fly from the Pan Am building in New York to JFK for like twenty five bucks or additional to your feet, which was great. OK, so you would do that. And they were doing it with Sikorsky's, I think. So the land on the top of the Pan Am building. So they actually had an accident. There was a wind. There was a dynamic roll over. The helicopter fell off the building into the street and killed a woman on the street in New York City. So as a consequence of that, it's illegal to land a helicopter in Manhattan. OK, so that and you say, well, but there are heliports in Manhattan. It turns out, if you look carefully, the heliports in Manhattan are actually in peers over the water. They're not in the land in Manhattan. OK. So those are the kind of things that that that happened. So this is one of the miracles that would have to occur for urban air mobility to really reach this vision that people had is suddenly you'd have to have all these facilities all over the place that will be very hard to get into each of the neighborhoods due to local licensing and all kinds of things that go on. And it actually wasn't just New York, but also scheduled helicopter service on a very frequent basis out of San Francisco as well. So you're exactly right. We we did do it with traditional helicopters. But and actually, as I understand it, some of the celebrities will go from their home G.A. Airport to, you know, LAX to catch their international flight by helicopter, although that's certainly not scheduled commercial service. That's private general aviation. So and that and that is the killer app for urban air mobility when we look at it, which is going to an airport, right, which means which turns out from a system standpoint, remember, we're talking about the the airspace use between commercial transports and in the in urban air mobility. That has to be worked out at that at that nexus. And it's they don't want to be shutting down landings that JFK to allow, you know, some helicopter in there. So you, you know, coming up with rules and how you do that is it's been one of the big focus and challenge. Thank you. We have one more in the back. Hello, I have a question. So traditionally on commercial aviation, when there's a contingency event, they usually do the contingencies managed through traffic traffic management, air traffic control. But now that we have all the autonomous systems, let's say UAM or UTM, that according to the con ops, that it's the is the service providers that helps resolve the situation. But how do we how are we prepared to transition from the purely ATC to service providers operated contingency management? Do you have anything to say about that? So that that's a great question. And that's so I don't know which kind of you're talking about, but there are a lot of con ops that were proposed that actually didn't make much sense because they didn't address those problems. So there was this notion of this distributed system and whatever, but you really have to structure the authority of who has access to the airspace, who does the approval and things like that. So I think that that's that's one of the reasons why I thought the wiskops was pretty good, because it's sort of thought through that a little bit better than some of the other ones. So they just separate out the air traffic control from the service provider and have a pretty good architecture. But it's it's totally legitimate comment. OK, and I mean, there is a real challenge on all these things when you have a con ops, you have to figure out all of the transitions that have to occur to make it reality. So who has to give up airspace? How does the system work? Will everybody buy in? And that's a real challenge. Yeah. Yeah, one thing I was going to comment on is for airports, there's been a move to have an integrated operation center where we can have all players close together physically. They work together on a day to day basis. So when you do have an emergency, you can step in and you can manage it more effectively. So now if we're adding a remote operation center, that obviously lends another degree of complexity to it. So again, probably scaling the system and identifying a limited number of service locations at first would be an important step to identify sort of the role and how that works. And one other aspect and all that, again, which is the big challenge is when you have competing agents and who has priority. Right. So that's the fundamental issue. Who makes the call on who goes first? Well, and I think the other point we've spent a lot of time today talking about commercial, the overwhelming number of airports in the U.S. are not scheduled, commercial, towered, all the big heavy players. So you would start asking what's the role of the community airport? I can start thinking about a lot of these smaller vehicles, different missions starting out from like a Columbus as a community airport or something like that. There are a lot of other capabilities here. But then the con ops has to be able to handle that level of operations as well as the Indianapolis Midway O'Hare sort of operations. And so layering the con ops for the different classes of service for the different classes of vehicle starts to be, I mean, you're in essence redesigning the national airspace. But that's also where it gets kind of exciting because we have a whole different role for some of our smaller airports. A few years ago, United actually put out a press release that for some of their small electric aircraft, one of the, you know, they describe the sort of the target market and they use the example from our Purdue airport to Chicago, which wouldn't that be fabulous? And of course, that might have been some of our graduates who are giving some PR. But again, you're right, it does change it. But that's where it gets exciting in terms of, wow, we can really tailor our air system to meet the needs of the nation. And we have another question in the back. Go ahead. Good afternoon. I have questions about wanting to follow up on the topic of urban air mobilities. So I think looking at these UAM startups, these startup aircrafts take so many different shapes and forms. And some of them have the capability, or some of them have the capabilities, also the failure modes as a traditional aircraft, not to say I'm losing a propeller, losing an engine. But there are also some of the capabilities, also the failures that the traditional fixed wing aircrafts or helicopter aircraft doesn't have, let's say, transition between cruise and hover. So my main question is one day there will be accidents. So what are the challenges for the engineers to analyze and learn from these failures when they happen? How do we count for these differences between the conventional and the new aircrafts? Yeah, I mean, I think this is the crux of what we've been discussing a lot today. There are new airplanes, there are new failure modes, some of which we will anticipate and design for. And we'll find them, by the way, in flight tests in the whole development process. Anytime you make a major change of the system, then you also have unexpected properties, emergent properties. So there are probably failure modes out there that we don't anticipate. Those are some of the things we talked about. Those will be the entry to service effects. We will be monitoring them very closely. One thing we haven't done well enough is to, which we're trying to do a little bit more, is to use the UAV, the small UAV system, as a surrogate to look for changes that occur there. But we don't have a way of tracking small UAV accidents or incidents or things like that. We will, on these newer airplanes, have a way of tracking any failures. There will be a requirement to report and things like that. So there will be a process as they come in. And there'll be a very stringent process on certification, which is why it will take longer than some people speculate. Do we have one question? I think our last question. I have an airport-specific question. So I'm from Atlanta. So I'm used to Hartfield-Jackson. But I've read that a lot of the some of the problems with how busy it is comes from them not having a second airport around Atlanta. So I'm wondering what are the pros and cons of adding that second airport and then what are the difficulties that you have to deal with communicating between two very closely nearby airports? Yeah, that's a really interesting topic. Actually, there has been a push to have a second airport in Atlanta. But then, quite frankly, Atlanta pushed back. Atlanta-Hartsfield Airport and did not want that secondary airport. And we see it with other cities as well. I don't know if you know, but there is a third airport planned for the Chicago area. And of course, New York has three airports. So it really becomes an airspace issue in managing the airspace. So that and I guess that's a fair question as we talk about these other kinds of aircraft. We might start to get those issues at other airports as well. So I sort of answered your I didn't really completely answer your question. But I guess I talked a little bit about surrounding issues. I think, you know, again, if this is on commercial transport airplane, if you look back, some airports that were getting significant delays in the 80s, you saw the expansion in Chicago as an example. But in Boston, we had Manchester and Providence show up. Typically, Southwest Airlines was the one who introduced those kind of expanded services. I think the problem there is that that's fine if you want to go to that basin, but you can't like transfer flights and whatever. So there isn't a real efficiency of the consolidation, which is, I think, why Atlanta went there. I would like to circle back, though, to what's come back on the discussion of a lot of these advanced air mobility, urban air mobility, want to go to the airport. OK. And it turns out under our current regulations, it's actually fine and visual a nice day. So the helicopters or the AM can come in as a way that are not interfering. If the weather's bad, OK, there's a three mile separation and it turns out that legally you can't do it. So we need new rules in order to get those AM airplanes in in a way that don't interfere or slow down. And I'll give you one other anecdote. We remember talked about priority. The highest priority airplanes in the system are Medevac airplanes. OK, they actually have priority over the over the president. OK, Air Force One is number two. OK, Medevac is number one. OK, so if an airplane, if a Medevac helicopter is flying into Boston, I'm sorry, Mass General Hospital, that's within three miles of the final approach course to Logan. So if that occurs in instrument conditions, they have to shut down Logan till the helicopter gets into the hospital. Now they've worked it out. If the helicopter, if they can get below the clouds, we'll do it and then they'll they'll cancel and not shut that down. But that problem has to be solved in instrument conditions in order to open up the air mobility access to the airports. And I think it will be, but that's we have to work the rules. A lot of implications to that. And we definitely appreciate all the questions and thank you so much. Can everyone give a hand to the committee? To the panel. And also, thank you to Brandon, Dr. Sun, Dr. Laveson, Dr. Hansman, Dr. Caldwell and Dr. Hubbard. Thank you. And thanks for sticking with us for the panel. I'm sure the panels will hang out for a few more minutes if you want to chat with them. Otherwise, enjoy the rest of your afternoon. Thank you, everyone.