By Cat Hofacker|September 2020
This is not the 2020 Mike Delaney expected. After the record number of travelers reported in 2019, the air transport industry now predicts demand and revenue won’t reach pre-pandemic levels before the mid-2020s. Key to this recovery will be keeping passengers healthy, so Boeing in May appointed Delaney to lead the just-created Confident Travel Initiative. Delaney’s staff members have been conducting research on new sanitation methods including ultraviolet light and advising airlines that fly Boeing jets on sanitizing cabins and cockpits via disinfectants already approved by the U.S. Environmental Protection Agency. I spoke with Delaney via Zoom during AIAA’s virtual Aviation forum in June to learn more.
IN HIS WORDS
Minimizing covid-19 risk
In thinking about covid-19, I try to bring the best of aerospace principles and practice to solve the problem. We’re not doctors or medical people; we’re airplane people and we’re aerospace folks. As an old chief project engineer, I think about how we assess airplanes from a threat point of view, whether that threat is lightning strike or windshear or malfunction or cessation of function. So for me, it’s natural to think of the covid-19 virus as a threat to that too, to the passengers and crew in the airplane. How we would solve that in the aerospace industry is we would design around the requirement to minimize that risk. So if you think about it in your public life, you hear about 6-foot social distance or wear a mask or use hand sanitizers or wash your hands. Those are all solutions for people in the medical community. You’re giving guidance to lower the replication rate of the disease. In an airplane, we want to lower the replication rate to below what you would experience in your everyday life, because we think the air travel system can do that. But we also know that a design solution of 6-foot social distancing won’t work on an airplane, so it will have to be some other design solution, maybe masks, sanitizers, something else that we’ll put into the model to say, “This is equivalently safe or safer than what you would experience in your day-to-day life.” And then we have to provide the information for people so that they can make decisions on that risk, because while the air travel system is built on an average risk, people have to think about their own personal situation — their health, their risks, their comorbidities — and take that into account.
Making an anti-covid-19 manual
We laid three layers of protection, the first being try to minimize the virus entering into the travel experience. That’s things like temperature screening and people choosing not to fly when they don’t feel well; it’s really the whole experience from when you leave your house to you get to your destination. The second layer is to have a clean airplane environment. That involves us putting together a cleaning program that we think about a lot like the maintenance service program or the engine maintenance program, where Boeing provides information in the maintenance manual, how to do a task. Then we provide the frequency and inspection update in the maintenance planning document. And then the third layer of protection is just like anything else in analysis: you assume that the virus gets on the airplane, so what inherent features in the airplane and in the operation can minimize the spread of transmission? And then we take those three layers of strategy and think about them against three time horizons. And we’ve been thinking about it in terms of zero to 90 days, and then 90 days or three months to about a year, and then a year to two to three years.
Assurances on cabin air quality
The current system is a mixture of fresh air and recirculated air. It’s about 50/50. The air that is recirculated goes through what’s called a HEPA filter. Those HEPA filters are 99.9-plus percent efficient at removing all particles. They are also efficient in the size range of viruses, bacteria and molds. No one in the industry has covid-19 [pathogens] to actually test against the filter, but the HEPA filter manufacturers have tested the range of viruses, and the covid-19 molecule is the exact same size as the virus range they’ve tested. I’ve talked to our supplier, and they would say it is an absolute legitimate statement to say that we believe the filters on the Boeing airplanes are effective against that size molecule.
Cleaning smarter, not longer
It can’t be a technology play by itself in terms of modifying the airplanes. The Boeing fleet today is almost 13,000 airplanes. To modify that many airplanes is probably a 10-year time horizon. So when we look at our first horizon of zero to 90 days, it’s really providing the airlines with the tools to keep the airplanes sanitary and clean today. And so that’s making sure that they’re using cleaners at a greater frequency than they historically would have. The next thing would be what can we do to relieve [airlines] and make this increased cleaning an easier burden as the fleet comes back? And that’s where you get to things like antimicrobial coatings. There are off-the-shelf antimicrobial coatings; we’ve already approved one. Then long term, you start looking at inherently building parts that have that antimicrobial coating characteristic in the part itself, as opposed to a coating. We’ve also looked at our ecoDemonstrator self-cleaning laboratories, where you bring in things like UV light.
Investigating UV light
We’re working with some university researchers to see if we can qualify ultraviolet light as a way that airlines can clean particularly sensitive areas like the flight deck, where you worry about fluid intrusion and other potential risks. We think there’s a lot of promise in UV light for a sanitizing capability, but the devil’s in the details. You need to understand the intensity and the duration. Both of those factors are important to whether or not it is effective. So if you look at a consumer example, you’ll see people can buy on Amazon UVC phone sanitizers, but they’re a 10-minute dwell time. So in order to have a faster cycle, you need greater intensity, right? That’s what a lot of the research is: How do you get something that provides the intensity and the power to have the short enough time to be effective and still be efficient in the airplane environment?
The cost factor
The good news about the urgency is it takes a lot of things off the table that could be on the higher end of cost, especially when you have a large fleet. And remember, any modifications need to go through more than just the certification, but the efficacy. I think when you start getting to people who are promoting things like UV lights that are always on, those things will start to become more expensive, but those are also not going to happen in the short term. And those will also have to go through not only the [FAA’s] Part 25 and the Part 121 operational certifications, but they’ll also have to prove their efficacy, because all cleaners and the things we recommend, we have guidance from the EPA that says, “This is what you need to do to use this, to have an effective cleaner.” We’re going through that process now with our UV wand. So even though we have a lot of hope for the wand, think about the industrialization of now getting that out there to the world’s flying fleet, and how many does an airline need for their fleet and the number of destinations and city pairs that they fly [between]. And so it’s going to take care of itself a little bit. When you get to the longer term, airlines are going to go through the break-even analysis: Is it better to use solvents and cleaners and the maintenance practices over here, or is a long-term thing, proving that efficiency? And the good news is that that’ll be a year out, but right now it’s getting a good cleaning program, and getting a good operational set of procedures to have a clean airplane and to minimize the ability for the disease to transmit in the travel experience.
Building changes into the system
In the midterm, we would bring things to bear that could help with the efficiency as the air traffic system comes back. So today the airlines can deal with a lot of things simply because the frequency is down. The number of flights is down, the passenger load is down and the gate and the turnaround times are longer. But as the system comes back, load factors go up, capacity goes up, turn times go down. It’s going to be harder and harder. The next phase is bringing them things that enable them to support the return to flight. And then in the long term, we have to build things in and provide things that enable airlines to provide the level of service or operational models that they have. So if you’re a 737 operator and your airline is built around frequency, say eight to 12 flights of that airplane a day with a 40-minute turn time, we have to provide a cleaning program that can be supported in that turn time. We want to add the economy and efficiency to the level of cleanliness and safety that we expect and are going to demand from the industry.
The new way of flying
Things like antimicrobial coatings [such as on tray tables] probably are going to be here to stay. My personal belief is, if you believe we’re 102 years from the last pandemic, I don’t think it’s going to be 102 years to the next one. So as an industry, we should learn the lessons from this one. I think that UV light will also become something that probably becomes a tool in the toolbox of the industry and airlines because we are always going to have sensitive electronic equipment in airplanes, and liquids of any form are always — if it’s not a safety issue — going to lead to an economic issue, clogged filters or disruption to the systems. And then while all the original equipment manufacturers design airplanes around air quality and comfort, it’s primarily around the smell of kerosene and jet fuel, those things not ingressing into the cabin, but it was also about not having drafts or temperature, gradients or velocities in the cabin. Those design features were really good for us in terms of covid-19, but we never actually had specifically “prevent the spread of an airborne virus” in our requirements documents. And we’re looking at that; should those things be brought now into the fundamental requirements documents that we design the next generation or two?
Requirements for future aircraft?
We’re always careful about bringing in new requirements because writing a good requirement is actually one of the art forms and one of the best skills that we have in the aerospace industry. And so, we’ve got a team who’s looking at how would we write those requirements. You have to think through it, not only the consequences of a requirement but the unintended consequences of a requirement. And then you say, “Should it be a requirement? Should it be an objective? How would we validate that requirement? How would we allocate that requirement?” So we would always be very careful, just like any new requirement. Everyone thinks of the 787, the first all new composite airplane, but it was built on years and years of composite development in components on other airplanes or other parts of other projects that were then put together as a complete package. This conversation is really about the next new Boeing airplane. Then we sit there and say, “OK, with the fleet we have today, are there things that we could offer to the fleet?” Just like airplanes get better through time, you’re probably talking about looking at the things you can do with that existing platform. It’s always a compromise between all those: What you can do and what you’d like to do, and what is practical and pragmatic, and time and financially efficient, without compromising the fundamental safety requirements of the airplane.