Reykjavík and Düsseldorf, probably some enconding mistake in the airport json file.

When /spot dubai or dxb we get back flights from an area in China, instead of Dubai airport.

There is info about the runways of each airport in the world, including coordinates. It's possible to create bounding boxes for each.

Dealing with multiple boxes
Even an airport with only one runway will have more than 1 bounding box, and it's not obvious from the data which direction is in use at any given time.

• query all bounding boxes and keep only flights towards/from the airport
• query the boxes one by one in a loop
• maybe it's possible to use wind speed/direction to choose direction

Example:
{:aircraft "C56X", :speed 216, :start "", :lon 13.244, :lat 52.5556, :flight "", :end "", :altitude 106, :track 81}

There should be checks for missing data, and handle them more gracefully than leaving the user waiting for an answer.

Since there is freely available information about airports, the control tower could have an endpoint providing this information.

• picture of the airport from mapbox
• current time and weather
• general information about runways, year of opening, maybe some stats from Wikipedia

Search could be by IATA or just city e.g. /airport DXB or /airport Dubai returns either the specific airport or the airports in that city.