The Flight Attendant

The Flight Attendant is an interactive harm reduction tool. It indicates the relative safety of various drug combinations based on TripSit’s Guide to Drug Combinations. While you may be familiar with a drug’s effects, combining it with other drugs may have unexpected and unsafe interactions. Press 2 or more buttons on The Flight Attendant to see the relative safety of that combination.

In addition to educating participants about responsible drug use, The Flight Attendant also collects anonymous usage data. We can answer a variety of questions with this data: What drugs are participants at a particular festival most interested in? What combinations? How many drugs may a participant use at once? What dangerous interactions are most likely? Answering these questions not only furthers the field of harm reduction research; it provides critical data to safety teams at festivals.


We brought The Flight Attendant to three festivals: a friends-and-family gathering with 150 people, a regional festival of 1150, and a global festival of 70,000.

We logged 55,000 button states: the raw data indicating time pressed (millisecond accuracy) and which buttons were pressed. 6,500 of these states were combinations of multiple buttons pressed for more than 500 milliseconds, which we use for further analysis. We detected 500 unique “sessions”, each with at least one minute of inactivity between.

Working with the 6,500 “real” combination tests from this data, we start with total number of tests for each drug:

LSD is most popular, followed by alcohol, MDMA, cannabis, and psilocybin mushrooms.

Given each pair of drugs, how often was each tested? Here are the top 20 pairs, color-coded by their relative safety:

Cocaine and alcohol is the most popular combination rated unsafe by Tripsit; ketamine and alcohol is the most popular rated dangerous.

Participants can press more than two buttons at once, testing as many drugs in combination as desired. The Flight Attendant displays the worst-case safety rating: caution for any pair overrides low risk; unsafe overrides caution, etc. For tests involving three or more drugs, we plot the 20 most popular triple-combinations:

Alcohol is present in nearly all popular triple-combinations and often contributes to a caution or unsafe rating.

Getting more ambitious, we plot all pair data in a chord diagram:

Click for interactive version

The size of each drug on the circle indicates the total number of tests for that drug. Each chord connects from one drug to another; the thickness of this chord indicates the number of tests for this particular combination, while chord color indicates the combination’s relative safety.

View our analysis as a Jupyter python notebook.

This is hosted from the project’s GitHub repo, which includes Arduino source code that runs on a Teensy 3.5.

The Future

We love bringing The Flight Attendant to festivals and events. Contact us if you’re interested in an appearance.

We want to make a next-generation Flight Attendant: full-size classic video game arcade cabinet, LED pixel-art screen, and retro sounds. This version will guide the user through an interactive process: displaying pertinent information for each drug, explaining the reasoning behind various interaction ratings, and collecting optional demographic data. Let us know if you’re interested in funding this project.

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The Flight Attendant is a collaboration with Jennifer Fernández, PhD