Suppose we have a position on earth with coordinates: (latitude, longitude). I'm looking for methods, algorithms or APIs to get a time alert that a plane would fly overhead in the neighborhood of that position. What are my options? Here are my thoughts:

  1. Use a web-based API to query all planes in the interest bound, periodically.

Downside: For average speed of airplanes (1000km/h), for a 1 degree in variation in latitude/longitude (approx. 100km), we have to probe the API every 6 minutes so not to miss the overhead plane. For a 0.1° variation (~10km) which fits the "flying overhead" description more accurately, this probing period is 36 seconds which is too much of a burden on both the machine and endpoint server.
This does not give us a "time-of-arrival" per se. It just continuously checks for overhead flights.

  1. To solve the frequent probing issue, first, use the API to query for flights in a bound much larger than interest bound. Then for all matched flights, only choose those whose predicted route passes over the interest region. This method gives us time-of-arrival.

Downside: How can we "predict" a flight route? We can use "dead-reckoning" meaning we assume a fixed heading, then predict the time of arrival of the plane in the interest region according to its initial speed. But problem is, planes may change their heading arbitrarily. So we may miss some planes who were not even in the first probing phase to begin with, or we may have false positives for planes which change their route after our probing.

  1. Use some fixed predefined flight route API.
    a)I don't know of any such APIs that provides routes or waypoints.
    b) The timing may be well off due to frequent delays in the industry.

These are all solutions I could come up with. Any ideas?

  • 2
    $\begingroup$ This is too broad. You need to provide the kinds of data you have available and some performance parameters/metrics. How far ahead do you need to know. How accurate do you need to be? How much compute power do you have available? What information about a flight is provided by your API? Destination? $\endgroup$
    – Jim
    Commented Mar 14, 2022 at 22:26
  • $\begingroup$ @Jim I'm ok with 30 minutes or 1 hour scan period for flights in any bounds (so a 0.5/1 hour early alert. ) Consider the neighborhood to be within 0.1° latitude/longitude of observer position. Compute power is typical modern PC (it's not an issue) but too frequent calls on API is not desirable. Flight heading, elevation, speed, lat/long, ICAO identifier. Any origin and any destination. $\endgroup$ Commented Mar 14, 2022 at 22:34
  • $\begingroup$ Is this for any flight including ad hoc GA private VFR flights or for scheduled commercial service only? $\endgroup$
    – Jim
    Commented Mar 14, 2022 at 22:40
  • 1
    $\begingroup$ This is more about programming, algorithms, and an API than it is about aviation. VTC as too broad, though off-topic also applies. $\endgroup$
    – Ralph J
    Commented Mar 15, 2022 at 0:09
  • $\begingroup$ Have you heard of Flightaware.com? If not, check it out. If so, maybe you could help us understand the actual end goal or problem at the root of this? (assuming this relates to your other question?) I mention it because perhaps there is a simpler way to address your actual objective... $\endgroup$ Commented Mar 15, 2022 at 0:55

1 Answer 1


I don't think there's any "easy" way to do this, but your best bet is probably to create a data table of flights linking city pairs served by scheduled commercial carriers that may cross your region. This could be done using flight planning software, including free web based such as Skyvector, or the old fashioned way with a paper chart and plotter.

Draw a radius, (or square) around your location of interest, and count how many flights cross the area you have determined the size of from your other question here: Hearing plane overhead

Then look up departure and arrival times of all the airlines serving the city pairs you've identified as crossing your region of interest. Enter the flight times in your table, and based on time/distance, calculate the point at which they enter and exit your designated area. From this information you can make a column that will show that local time based on scheduled departures.

If you are computer savvy and want to automate things, write a program that will sample web info for posted departure delays and have your table updated automatically. Then have the entry and exit times you've calculated "ping" your computer to alert you so you can go outside and listen.

I can't offer a suggestion on how to accomplish that last part because it is about computer applications, and not aviation.

Anyway, without more information on your actual location or the desired outcome you seek you probably won't get much more than the answer I'm offering...


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