In recent weeks, there has been an interesting debate about how fast we should re-open various parts of our country.
Some people have been circulating charts and graphs that do not show spikes of infections or hospitalizations in places that re-opened more aggressively. From these charts they draw the conclusion that they must have been right all along, and the lack of spikes is conclusive proof that it is safe to re-open everything.
These people’s reasoning may turn out to contain a fatal flaw. Because such graphs and charts present indirect evidence of risk, and can be misleading.
Let me explain with an example.
I have been a commercial pilot for more than fifteen years. I do not fly for a living but have enough skill an hours to get hired by a sketchy regional airline. I have served multiple times as a civilian test pilot for NASA human factors research and as a volunteer pilot for Angel Flight.
Each time I fly, I follow certain procedures. As I approach to land, I verbally complete a pre-landing checklist while physically touching each switch to help confirm I have performed the corresponding checklist item correctly.
Included in my checklist are these two items:
“Undercarriage” — touch the landing gear switch to confirm that the landing gear is down, locked, visible, and the green landing lights are illuminated.
“Fuel” – touch the fuel control to ensure it is set to feed from both fuel tanks.
I have checked my fuel and undercarriage probably ten thousand times on final approach. They have been where I expected 99.9% of the time.
What this means is that if tomorrow I stopped running my checklist, I would not immediately crash. A chart of my landings would continue to show zero crashes — probably for a very long time, even though I would be reducing my margin of safety in a way that would be real but would not show up in crash statistics . . . until the day my luck runs out.
In other words, if I keep flying for many years it is inevitable that sooner or later I will have a landing gear problem or I will forget to flip the switch to lower the landing gear. And if I have skipped that checklist item I will not know the gear is still up. And I will crash land to my great regret, assuming that I survive.
It is important to understand the between now and then I might land five thousand more times. But the fact that I don’t crash during those 5,000 flights does not mean that the landing checklist was unnecessary. Because during those 5,000 flights I will have been exposing myself to increased risk, despite the number of crashes remaining at zero.
Complacency is one of the main risk factors we fear in aviation safety circles. Everyone is at risk for it. Every time we fly we are expected to physically drain some fuel from the tanks to confirm there is no water contamination. Some complacent pilots who have drained the fuel five thousand times and never seen contamination start to occasionally skip that step because they get complacent. And most of them get away with it for years or even forever. But every once in a while, this happens, and sadly reminds the rest of us why we should remain vigilant.
The same principle applies to people states where they are re-opening aggressively. Social distancing, masks, and hand-washing are designed to protect against the spread of the virus. If people stop doing those things they are voluntarily exposing themselves to sharply increased risk. And they are at great risk for drawing the wrong conclusions if they go to the beach, party, get haircuts, and don’t catch the virus. Because the reason that they didn’t catch the virus may be that they were not exposed to the virus at all during those risky interactions.
Indeed, it is important to understand that there are unquestionably hundreds of thousands of places in the country where the virus is not currently circulating. The people who live in those places could literally set up a hugging booth on Main Street and create a new custom in which everyone shakes hands and then licks each others hands hello. Even then, nobody would contract COVID-19 if it is not circulating in those communities.
Of course doing those things would be very risky because unless those communities are completely isolated, there is a risk that someone with the virus will show up to town and inadvertently kick off a cluster of infections.
People are fleeing Brazil right now just like the fled Europe and they fled NYC. Many of them may be pre-symptomatic but contagious.
The net result of this is likely to be that when a community outbreak occurs in a place where people are not protecting themselves, such an outbreak will result in a sharp spike in infections, hospitalizations, and deaths.
So far I have not seen any good charts that attempt to quantify the risks that people take when they flaunt recommended health protection requirements. It would be nice if we could find a way to make that point to people other than showing them the blog post of a nobody who loves to take risks so long as they are well-informed.
Bart's Blog 
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