Following a Flight Over the Ocean: What You Will See

Tracking flights over the ocean feels different from watching one over land. You open a map, find the aircraft heading out past the coast, and at some point the dot stops moving the way you expect, or stops updating altogether, while the plane is somewhere over open water. Nothing has happened to the flight. What has changed is who can hear it. This piece walks through a typical ocean crossing in four stages, what a public map is likely to show at each one, and what air traffic control is doing at the same moment, because the two are not the same picture.

Stage one: leaving the coast

Most public flight maps are built on ADS-B, short for Automatic Dependent Surveillance-Broadcast. The aircraft works out its own position using satellite navigation and other sensors and broadcasts it at regular intervals, along with details such as altitude, speed and callsign (Wikipedia, "Automatic Dependent Surveillance-Broadcast," captured 2026-09-27). A number of websites collect those broadcasts through crowd-sourced networks of ground receivers, the same source notes.

A ground receiver can only hear what is within its radio reach. The US Federal Aviation Administration puts it plainly in its ADS-B FAQ: range depends on the aircraft's altitude and on any terrain blocking the line of sight to the station, with further practical limits set by transmitter power and receiver sensitivity (FAA, ADS-B FAQ, captured 2026-09-27). An aircraft at cruising height can be heard a long way out, but not indefinitely. The same FAQ gives a concrete example from the Gulf of America, as the FAA page names it: before ADS-B stations were installed there, air traffic control had no surveillance at low altitudes or beyond 200 nautical miles, about 370 kilometres, from the coast.

So the first stage of an ocean crossing usually looks ordinary. The aircraft climbs out, heads for the coastline and stays on the map for as long as receivers on land, or on the occasional island, can still pick it up.

Stage two: the quiet middle

Somewhere past the coast, a map fed only by ground receivers runs out of listeners. The aircraft keeps broadcasting exactly as before. There is simply nobody close enough to catch the signal, because receivers sit on land and the open ocean has very few places to put one.

What you see at that point depends on how the map is built. It may leave the last position it heard in place, or it may draw an estimate along the expected path. Either way, the dot is no longer a fresh report. The most useful habit is to look for the time of the last update, if the map shows one, and to treat any position older than a few minutes as a last sighting, not a current fix.

There is one important exception. ADS-B signals can also be picked up by receivers carried on satellites in low Earth orbit, which extends surveillance into oceanic and remote regions beyond the reach of ground receivers; the first operational service of this kind started in 2019 on the Iridium constellation (Wikipedia, "Automatic Dependent Surveillance-Broadcast," captured 2026-09-27). Whether a given public map includes satellite-received positions depends on where that map gets its data, which is a question for the map's own documentation.

This is the stage behind the search "why planes disappear over ocean". The honest answer is that the plane has not disappeared. It has flown out of earshot of the ground network that particular map relies on.

Stage three: what air traffic control sees meanwhile

While a public map goes quiet, the flight is still being controlled, and controllers still know where it is. Over the ocean, that has long worked differently from radar-covered airspace over land.

Position reports by radio. Where there is no radar, including over the ocean, controllers use procedural control. Without newer datalink systems, that separation rests on the flight crew reading out their position by voice over HF radio, often relayed through an HF radio operator (Wikipedia, "Future Air Navigation System," captured 2026-09-27). Before satellite surveillance, controllers received those position updates over the North Atlantic roughly every 10 to 14 minutes, according to NAV CANADA (NAV CANADA, "Space-based ADS-B surveillance improves trips over the North Atlantic," captured 2026-09-27).

Automatic reports over a datalink. A system known as FANS links equipped aircraft to air traffic control through satellite networks such as Iridium and Inmarsat. Part of it, ADS-C, lets a controller set up a "contract" with the aircraft's navigation system so that it sends position reports automatically on a set schedule, every five minutes for example, without the crew having to call them in. Another part, CPDLC, carries text messages between controller and pilot. FANS was designed for airspace without radar coverage (Wikipedia, "Future Air Navigation System," captured 2026-09-27).

Published tracks across the Atlantic. The busiest ocean crossing has its own structure. The North Atlantic Tracks are a set of routes published twice a day by the Shanwick and Gander oceanic centres, in consultation with neighbouring air traffic control agencies and airlines. They shift from day to day with the winds aloft, especially the jet stream, and with the main flow of traffic: eastbound flights to Europe use the tracks at night, and in daylight the tracks carry westbound traffic. Aircraft on them report position by CPDLC over a satellite link or by HF radio, and aircraft equipped with ADS-C and ADS-B no longer need to make voice position reports on HF (Wikipedia, "North Atlantic Tracks," captured 2026-09-27).

Stage three and a half: satellites over the North Atlantic

The biggest recent change came in 2019. On 27 March 2019, NATS and NAV CANADA became the first air navigation providers to put space-based ADS-B into operational use, using a service from the satellite surveillance company Aireon (NATS, "Six years of Space-Based ADS-B," captured 2026-09-27). The satellites receive the same ADS-B broadcasts that ground receivers hear over land, and pass them to controllers every few seconds (Wikipedia, "North Atlantic Tracks," captured 2026-09-27).

That let controllers space aircraft far more closely. For equipped aircraft, NAV CANADA reports that the gap required between one aircraft and the next on the same path fell from 5 minutes, or 40 nautical miles (about 74 kilometres), to between 14 and 17 nautical miles (about 26 to 31 kilometres), and side-by-side separation fell from 23 nautical miles (about 43 kilometres) to between 15 and 19 nautical miles (about 28 to 35 kilometres) (NAV CANADA, captured 2026-09-27).

The practical point for anyone following a flight from home is simple: a map that has gone quiet tells you about the map's receivers, not about whether anyone is watching the aircraft. Over the North Atlantic, the controllers responsible for it have had satellite surveillance of equipped aircraft since 2019.

Stage four: coming back over land

As the aircraft approaches the far coast, it comes back within reach of ground receivers, and a map that relies on them picks it up again. From there, with land-based receivers back in range, the rest of the flight tends to look continuous again. The gap on the map closes on its own, with nothing for you to do.

Reading the quiet stretch without guessing

A few checks turn a silent map into useful information.

• Look at the timestamp before the dot. A position with an age of 40 minutes is a record of where the aircraft was, and the map may be telling you that clearly if you look.
• Use the airline's own flight status page for the arrival time. The airline's estimated arrival is a separate source from a map's position feed, so it keeps meaning something while the map is quiet. A steady estimate is a better read on the crossing than a frozen dot.
• Expect the pickup near the far coast, not before. On a long ocean leg, the quiet stretch can last hours. Its length says more about the geography of receivers than about the flight.
• Know which route you are watching. A pair like Singapore to London, which has its own route page in our directory, follows a different path from a transatlantic crossing, so the time a map spends out of receiver range differs from one route to the next.

How TrackMyWings helps

TrackMyWings™ is a live flight-tracking platform in development, built for the people waiting. A private beta has been running on Android since 2026-08-24, on the Play internal testing track, and there is no fixed public launch date yet. A live map and gate and status alerts are among the features planned for launch; our live flight tracking page describes that planned feature. Until then, the checks above work on whichever map you already use.

Questions people ask

Why do planes disappear from flight maps over the ocean? Because many maps depend on ground receivers hearing the aircraft's ADS-B broadcast, and receivers sit on land. Far from the coast, nobody on the ground is in range, so the map has nothing new to show until the aircraft comes back within reach.

Does air traffic control lose the plane too? No. Over the ocean, controllers use HF radio position reports, automatic ADS-C reports over satellite datalink and, over the North Atlantic since 2019, space-based ADS-B for equipped aircraft.

How long will my flight be missing from the map? It depends on the route and on which receivers the map uses. On a long ocean leg the quiet stretch can run for hours; the aircraft typically reappears as it approaches the far coast.

What are the North Atlantic Tracks? A set of routes across the Atlantic published twice a day by the Shanwick and Gander oceanic centres, drawn around the day's winds, especially the jet stream.

Where should I check the arrival time while the map is quiet? On the airline's own flight status page. Its estimated arrival is a separate source from a map's position feed, so it stays useful while the map is quiet.

Sources

• FAA, "ADS-B Frequently Asked Questions," https://www.faa.gov/air_traffic/technology/adsb/faq, captured 2026-09-27
• Wikipedia, "Automatic Dependent Surveillance-Broadcast," https://en.wikipedia.org/wiki/ADS-B, captured 2026-09-27
• NAV CANADA, "Space-based ADS-B surveillance improves trips over the North Atlantic," 2020-01-23, https://www.navcanada.ca/en/news/blog/space-based-ads-b-surveillance-improves-trips-over-the-north-atlantic.aspx, captured 2026-09-27
• NATS, "Six years of Space-Based ADS-B: transforming North Atlantic airspace," 2025-05-07, https://www.nats.aero/news/six-years-of-space-based-ads-b-transforming-north-atlantic-airspace/, captured 2026-09-27
• Wikipedia, "North Atlantic Tracks," https://en.wikipedia.org/wiki/North_Atlantic_Tracks, captured 2026-09-27
• Wikipedia, "Future Air Navigation System," https://en.wikipedia.org/wiki/Future_Air_Navigation_System, captured 2026-09-27