# ACARS Drama > ACARS Drama is a project dedicated to showcasing the behind-the-scenes, heroic efforts of commercial aviation. It is powered by a global network of aviation enthusiasts on the hunt for interesting cleartext ACARS and VDLM2 messages captured from passing aircraft using cheap radio hardware and free open-source software. All messages posted are stripped of identifying information and delayed by around five minutes for safety. Public feeds are free; a paid Jumpseat membership adds search, stats, and API access. Fediverse: @acarsdrama@live.acarsdrama.com --- ## Welcome ACARS Drama is a project powered by a global network of aviation enthusiasts on the hunt for interesting cleartext ACARS and VDLM2 messages captured from passing aircraft using cheap radio hardware and free open-source software. All messages posted are stripped of identifying information and delayed by around five minutes. (We should also probably mention most ACARS messages are very undramatic.) ### A note on ACARS Privacy/Ethics While ACARS messages have always been accessible to enthusiasts, there are a new generation of apps and services that share them, unfiltered, in real time. We are not one of them. Our mission statement includes the rule that we set out to enjoy the perspective ACARS gives us on the hard work that happens behind the scenes in commercial aviation. Our intention in sharing these messages is not to embarrass or cause issues for anyone. That's why we redact PII, identifiers, and other sensitive details and have a slight safety delay, unlike some services. In an ideal world, there would be no ACARS Drama, because ACARS would be transmitted encrypted over IP networks. Our stance is one of "just because you can, doesn't mean you should." We want to nerd out, sensibly, without causing problems. --- ## What is ACARS Drama? *"A project to map out every broken coffee maker in the sky."* Aircraft Communications Addressing and Reporting System (ACARS) — an aviation radio system that is older than you, probably. ### How a message reaches the feed 1. Plane flying over — drama occurs onboard. 2. Pilot reports drama via FMS keypad — transmits unencrypted data over VHF. 3. Signal captured by SDR — operated by a "sky drama farmer." 4. Software decodes ACARS — message parsed & cleaned. 5. Posted to the Drama engine — message enters drama processing. 6. Engine examines message — if drama found, post to feeds (after safety delay). ### The details When an aircraft is flying overhead, various radio signals are being transmitted and received constantly. Some are voice communications between pilots and air traffic controllers — critical for safety, ensuring planes are at the right altitude, direction, and speed. In addition to voice, there are also many data signals. Among these are the two types that feed the bot's insatiable thirst for drama: ACARS and VDLM2. **ACARS** (Aircraft Communications Addressing and Reporting System) is a 1970s-era protocol still used today. A set of ground stations around the world translate messages between computers in dispatch, maintenance and operations control rooms of the airlines and their aircraft, and vice-versa. **VDLM2** (VHF Data Link Mode 2) is similar — a data transmission protocol over very high frequency (VHF) radio waves — but it's a bit more modern, uses different frequencies, is faster, and can also carry ACARS messages. In summary, ACARS is where the drama usually is, sometimes transmitted in raw ACARS form, other times encapsulated in VDLM2. Same result — you just have to look in a slightly different place to decode the ACARS inside VDLM2 messages. There are lots of open-source software projects that work with software-defined radios (SDRs) to capture ACARS transmissions. ACARS Drama takes the output from these projects and formats them into the posts you see on the bot's social feeds. Because of how the system works, it's much harder to capture ground-to-air signals unless you live very close to an airport or ground station. So around 99% of what you see on ACARS Drama is air-to-ground — essentially one side of a conversation, from the plane to folks on the ground. When a ground-to-air message is picked up, the bot labels it "Ground to Air Message" instead of "Air to Ground Message." Because of the sheer volume processed — around 250,000 messages an hour, most of which are just position and weather data and automated equipment readings — it wouldn't be reasonable (or anything but annoying) to post them all. So the project curates a list of keywords to surface only messages with human-entered, "free-text" content. When you see a message on the bot, it means a pilot or crew member typed it into their ACARS terminal, usually a Flight Management Computer (FMC). The overwhelming majority of ACARS messages are extremely routine and boring — contrary to the name of the bot, which is part of the joke. You'll mostly see gate-confirmation requests and reports of "snags" (often toilet- or coffee-maker-related), but occasionally reports of drunk passengers, fights onboard, and other air-travel things. You also get to see pilots' personalities shine through. These are professionals doing a wonderful job in not always the easiest of circumstances. Follow along at https://live.acarsdrama.com/@acarsdrama --- ## Jumpseat membership — $7.99 / month The public feeds are free and will remain free. If you want to support ACARS Drama and nerd out even harder, Jumpseat membership is the best way to help keep the project running. It helps offset the real costs of hosting, storage, bandwidth, processing, and infrastructure. What began as a single Raspberry Pi hobby project has grown into a data firehose: a global volunteer feeder network processing roughly 250,000 messages per hour, enjoyed by thousands of aviation nerds around the world. What Jumpseat unlocks: - Search ACARS and VDLM2 messages beyond the public feed. - Explore recent traffic and archive sweeps. - Look up aircraft activity and message history. - Review station statistics, message volume, protocol mix, and published percentages. - Dig into ACARS insights and trends. - Use the Jumpseat REST API for personal dashboards, notebooks, home-lab projects, and experiments. Preview panels: Jumpseat Dashboard (live volume, unpublished message counts, ACARS insights, REST API access), Archive Search, Flight Playback (replay messages for a flight across live and archived data), and Station Reports (station stats, protocol mix, frequencies, message volume). Join: https://jumpseat.acarsdrama.com --- ## Contribute — Harvest your sky drama! If you'd like to contribute, it's easy with an RTL-SDR, an antenna, some open-source software, and Internet access. ### Quick Start - Send **ACARS** to **feedthe.acarsdrama.com:5550** - Send **VDLM2** to **feedthe.acarsdrama.com:5555** - UDP or TCP (UDP preferred), JSON format. Use **acars_router** to split feeds if you already feed elsewhere. - Set a unique FEED ID (include your nearest airport ICAO). Email *feeders [at] acarsdrama [dot] com* to confirm reception. - Sky Drama Farmers get complimentary Jumpseat membership — email after your feed is running to request access. ### Guides - Deep dive (acarsdec / dumpvdlm2 / acars_router): https://mike-sheward.medium.com/slack-messages-from-the-skies-9ea8ea9366f0 - Sample docker-compose.yml: https://github.com/acarsdrama/sample-config/blob/main/docker-compose.yaml - ADSB.im image + step-by-step guide: https://mike-sheward.medium.com/feed-acars-drama-with-adsb-im-a-step-by-step-guide-a78983f6ed18 - Ask questions in the "ACARS Drama Club" Discord: https://discord.gg/8MPufpn2qh ### Recommended equipment - **RTL-SDR Blog V3/V4** — reliable, inexpensive SDR dongles for ACARS and VDLM2 reception. https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/ - **NooElec NESDR Mini** — compact SDR with strong performance for aviation-band monitoring. https://www.nooelec.com/store/sdr/sdr-receivers/nesdr-mini.html - Tip: Use a VHF air-band antenna and mount it as high and clear as possible for best results. ### Recommended software - **docker-acarshub** — community-maintained ACARS/VDLM2 stack with built-in routing. https://github.com/sdr-enthusiasts/docker-acarshub - **ADSB.im** — preconfigured images for Raspberry Pi and other devices with ACARS Drama feeder support. https://adsb.im - Combine with *acars_router* to feed multiple networks efficiently. --- ## Feeds — a quick note The main ACARS Drama social feed is very busy (a tiny fraction of 250,000 messages/hour is still a lot). Below are more heavily filtered feeds and RSS options. ### Screen-reader-friendly version A mirrored, screen-reader-friendly version of the feed exists on both Bluesky and Mastodon, designed to be easier to follow with assistive technology. - Mastodon accessibility feed: https://live.acarsdrama.com/@acarsdrama_a11y - Bluesky accessibility feed: https://bsky.app/profile/acarsdrama-a11y.bsky.social ### Mastodon quieter feeds - **Main:** https://live.acarsdrama.com/@acarsdrama - **Trending** (reposts messages that get boosted/favorited a lot): https://live.acarsdrama.com/@trending - **Top Shelf** (stricter keyword set): https://live.acarsdrama.com/@top_shelf - **Emergencies & Failures** (broken things, system failures, emergencies): https://live.acarsdrama.com/@emergencies_failures - **Medical** (medical events): https://live.acarsdrama.com/@medical - **Excreta** (if it is launched from the human body, you'll find it here): https://live.acarsdrama.com/@excreta - **Bad Pax** (the worst part of flying is sometimes the people next to you): https://live.acarsdrama.com/@badpax - **WTF** (things that make you ask WTF?!): https://live.acarsdrama.com/@wtf - **Animals** (four-legged friends are not immune from drama): https://live.acarsdrama.com/@animals - **Weather** (weather-related happenings and diversions): https://live.acarsdrama.com/@wx - **Ride Reports** (bumpiness ratings): https://live.acarsdrama.com/@ride_reports - **Crewing & Ops** (operational side of aviation): https://live.acarsdrama.com/@crewing_ops ### RSS - Main: https://live.acarsdrama.com/@acarsdrama.rss - Trending: https://live.acarsdrama.com/@trending.rss - Top Shelf: https://live.acarsdrama.com/@top_shelf.rss - Emergencies & Failures: https://live.acarsdrama.com/@emergencies_failures.rss - Medical: https://live.acarsdrama.com/@medical.rss - Excreta: https://live.acarsdrama.com/@excreta.rss - Bad Pax: https://live.acarsdrama.com/@badpax.rss - WTF: https://live.acarsdrama.com/@wtf.rss - Animals: https://live.acarsdrama.com/@animals.rss - Weather: https://live.acarsdrama.com/@wx.rss - Ride Reports: https://live.acarsdrama.com/@ride_reports.rss - Crewing & Ops: https://live.acarsdrama.com/@crewing_ops.rss --- ## ACARS Glossary Common terms you'll see in messages. ACARS/VDLM2 messages are terse and very "ops"-y; this glossary decodes the most common shorthand. - **ACARS** — Aircraft Communications Addressing and Reporting System - **APU** — Auxiliary Power Unit - **ATC** — Air Traffic Control - **ATIS** — Automatic Terminal Information Service - **AOG** — Aircraft On Ground - **CA** — Captain - **CL** — Cabin Log - **CS** — Customer Service - **CDU/FMC** — Control Display Unit / Flight Management Computer - **CPDLC** — Controller–Pilot Data Link Communications - **DCT** — Direct (routing) - **EFB** — Electronic Flight Bag - **ECAM** — Electronic Centralized Aircraft Monitor (Airbus) - **EICAS** — Engine Indication and Crew Alerting System (Boeing) - **EDCT** — Estimated Departure Clearance Time - **EFC** — Expect Further Clearance - **ETA / ETD** — Estimated Time of Arrival / Departure - **ETOPS** — Extended-range Twin-engine Operations - **FA** — Flight Attendant - **FMS** — Flight Management System - **FO** — First Officer - **FOB** — Fuel on Board - **GPU** — Ground Power Unit - **HF / VHF** — Radio bands - **INOP** — Inoperable / broken - **JL** — Journey Log - **MEL** — Minimum Equipment List - **METAR / TAF** — Weather report / Forecast - **NOTAM** — Notice to Air Missions - **OOOI** — Out / Off / On / In times - **PAX** — Passengers - **PIREP** — Pilot Inflight Weather Report - **PNR** — Passenger Name Record - **QRH** — Quick Reference Handbook - **RON** — Remaining Overnight - **RVR** — Runway Visual Range - **SELCAL** — Selective Calling system - **SID / STAR** — Standard Departures / Arrivals - **TCAS** — Traffic Alert and Collision Avoidance System - **UM** — Unaccompanied Minor - **WX** — Weather - **ZFW / TOW / MLW** — Weights (Zero Fuel Weight / Takeoff Weight / Max Landing Weight) - **CTA / FIR** — Airspace regions See a term that's missing? Ping the project on Mastodon or Discord. --- ## Content Moderation + Legal Since its inception in the 1970s, ACARS messages have been readable to anyone nearby with an air-band radio attached to a computer. ACARS has long been treated as a public communications channel due to the lack of any encryption, and messages have been publicly searchable in a variety of places on the internet for decades. Pilots are advised not to use ACARS for sensitive data transmission, and to instead use airline-specific encrypted apps over IP networks. All that said, ACARS messages can sometimes contain personally identifiable information about passengers (even though they are transmitted completely unencrypted). The project's intention as enthusiasts is to enjoy the world of commercial aviation and nerd out — not to expose or embarrass anyone. The underlying code has checks to filter out things like names, medical details, and PNRs (Passenger Name Records); the actual characters are replaced by X's when this happens. The same is true for any security-related content that may have a safety impact. There is also a policy of delaying messages by five minutes and removing identification of the aircraft they came from. Sometimes things slip through and are removed shortly after; others might not be noticed immediately. If you see something that you feel does not belong on ACARS Drama, report it via the Mastodon instance. Information shared on ACARS Drama is not to be used for flight planning or during live flight operations. ACARS Drama makes no claim that the information shared is always completely accurate — the ACARS protocol makes it possible to spoof messages claiming to be from a specific aircraft. The project has built, and continually refines, spoofed-message detection, but this is the reality of protocols with no authentication or integrity checking. ACARS Drama exists for every aviation fan to enjoy another perspective on commercial aviation. It does not tolerate hate speech or any other discriminatory behavior on its platforms or tooling, and will remove anyone who doesn't treat others with respect. --- ## Support ACARS Drama is free to follow, free to read, and the public feeds will remain free — Mastodon, Bluesky, RSS, Discord, filtered feeds, and feeder participation are still the heart of the project. If you enjoy the project and want to help sustain it, becoming an ACARS Drama Jumpseat member ($7.99/month) is the best way to support it. Sky Drama Farmers who feed the project receive complimentary Jumpseat membership — email *feeders [at] acarsdrama [dot] com* after your feed is running. --- ## Links - Main feed (Mastodon): https://live.acarsdrama.com/@acarsdrama - Bluesky: https://bsky.app/profile/acarsdrama.bsky.social - Discord ("ACARS Drama Club"): https://discord.gg/8MPufpn2qh - GitHub: https://github.com/acarsdrama - Jumpseat membership: https://jumpseat.acarsdrama.com - Feeder contact: feeders [at] acarsdrama [dot] com