The commonest reason an aircraft vanishes is simple: nobody is listening. ADS-B needs a ground receiver within radio range, and over oceans, deserts, polar regions and sparsely populated land there may be none. A transatlantic flight can drop off coverage mid-ocean and reappear hours later near the far coast — not because it stopped flying, but because it flew out of earshot. Space-based ADS-B, where satellites carry receivers, fills much of this gap but is not part of every public feed.
Some aircraft are deliberately absent. Operators can request that an airframe be filtered from public displays, and certain military, government or sensitive flights either don’t broadcast standard ADS-B or are withheld from public feeds. A blank patch of sky may simply mean the aircraft there are not being shown, not that they are not flying.
Other tracks look wrong rather than missing. A short delay between broadcast, reception and display means a fast aircraft’s dot can lag slightly behind its true position. A momentary GPS or message error can throw a single point far off course, producing a spike or a teleport that the next good message corrects. Stale data — a state vector that hasn’t updated — can leave an aircraft frozen until its next broadcast lands.
The honest way to read all this: absence is not evidence. A gap on the map usually means a coverage hole, a filtered aircraft or a lapsed update — not an incident. FlightGlobe shows the age of each position so a stale fix doesn’t pose as live, and treats a vanished track as “out of coverage” rather than quietly guessing where the aircraft went.