Frequently Asked Questions

What is this data good for?

While ADS-B is not yet installed in every airplane, and not every ADS-B track will be in our database, higher-risk areas may still be detectable with enough data. Our hope is that the results are useful for three groups of people:

What interesting hotspots have you found so far?

How are you classifying events as Loss Of Separation (LOS)?

It is an arbitrary choice, balancing having too many events to process (and that won't crash people's web browsers) versus too few to see geographic patterns. See the Methodology page.

Are LOS events necessarily unsafe?

Absolutely not. Some are normal (e.g. simultaneous operations to parallel runways.) The connection with safety is not established, and may be hard to establish given the rarity of midair collisions. The idea here is to find areas and types of operation where pilots and airport operators may want to exercise more caution.

Is an airport with a high LOS/day count unsafe?

Not necessarily. See the previous question.

I see a certain tail number showing up frequently. Is that airplane being operated unsafely?

Not necessarily. Some aircraft fly a lot more than others, so they may naturally be over-represented. Also, some types of operation (especially training in the landing pattern) will expose the aircraft to more LOS events.

Where is the raw data coming from?

The raw data is provided by adsb.lol, who collect it from volunteers who receive ADS-B data and share it with them. If you're interested in improving coverage near you, you can learn how to feed data to them here.

Why isn't my favorite airport available?

Analyzing all this data is a big job, so initially only the 1000 or so busiest airports in the US are covered. If you want to see an automated analysis for another airport, search for it, then you will be prompted to submit it for analysis. If you are interested in a longer time-range and more detailed report, contact us.

Is this useful for towered airports?

That hasn't been the focus so far. Plenty of operations that are common at towered airports will show up in this analysis. Also, towered airports frequently have parallel runways, which generate a lot of false positives in the current algorithm. If you have thoughts on this, get in touch.

I see an event that is categorized incorrectly.

This is almost certain to happen given the incomplete nature of the data, and simple rules (see Methodology) being applied to the categories. But if you see something that you think could be improved algorithmically, by all means get in touch.

The data is noisy.

It sure is. There are many sources of false positives and other problems. Clicking on a number of events is likely necessary to understand the full context. Common sources of false positives:

There are very few or zero events at my favorite airport -- I can't see any pattern.

Most airports are showing a 3-6 months of data. More can be added in the longer term, but data before 2024 may have lower coverage and lower ADS-B-out adoption. Low events might also be due to poor crowdsourcing coverage of your airport -- if so, you can help contribute data to adsb.lol's data to fix this problem in the future!

What's the business model here?

This is a free service to the aviation community. The site and the data on it is free for non-commercial use and adaptation, and is licensed under CC BY-NC 4.0. The site contains information from adsb.lol, which is made available here under the Open Database License (ODbL).