Falsehoods Programmers Believe About Aviation

Summary

At FlightAware, our software needs to gracefully handle all sorts of weird and wonderful situations. While we as engineers might hope for aviation data to be clean and well-standardized, the real world is messy.There are a lot of assumptions one could make when designing data types and schemas for aviation data that turn out to be inaccurate. In the spirit of Patrick McKenzie’s classic piece on names, here are some false assumptions one might make about aviation. While many of these are simply common misconceptions, some of these assumptions have bitten our customers at various points, and others have caused issues in our own systems over the years.Together they are illustrative of the situations that Hyperfeed, our flight tracking engine, is responsible for correctly interpreting in order to provide a clean and consistent data feed for our website, apps, and APIs.FlightsFlights depart from a gateFlights that depart from a gate only leave their gate onceFlights depart within a few hours of the time they were scheduled toFlights depart within a day of the time they were scheduled toFlights have schedulesFlights take off and land at airportsAirplanes (excluding helicopters) take off and land at airportsFlights are at most a dozen or so hours longOkay, they’re at most a few days longFlights are identified by a flight number consisting of an airline’s code plus some numbers, like UAL1234Flights are identified by either an airline flight number like UAL1234, or the aircraft’s registration like N12345, B6459, or FHUVLA flight identifier like B6459 is unambiguously either a registration (B–6459), an airline flight number (B6 459), or something elseFlights don’t have multiple flight numbersFlights with multiple flight numbers unambiguously have one “main” flight numberA particular trip’s flight number(s) never changeThe flight number shown on your ticket is what the pilots and air traffic control are usingFlights don’t use the code of some entirely unrelated airline in thei...