I’ve been interested to understand if we might answer a supposedly simple question here in the Seattle area: are there fewer planes in the sky since COVID-19 came to town?

If so - how big is the drop?

Finding out the answer hasn’t been so simple. We’re not exactly asking about number of passengers, or number of worldwide flights. We’re asking about, on any given day, how many commercial jets pass through KSEA, and how that number has changed over the last three months.

The question is at once incredibly big (we know KSEA had 51.8M passengers come through last year), and very specific (we want to know how many actual aircraft - in other words: “which tail numbers?” - either landed at or took off from KSEA every day).