There is a specific kind of anxiety produced by a departure board that says Estimated 19:55 when your ticket says 19:20, and a different kind produced by one that says nothing at all. Airport boards, airline apps and flight trackers all use a shared vocabulary of status words, and almost none of them mean what a reasonable person would assume. Estimated is not a delay. En route is not necessarily airborne. Departed can appear while the aircraft is still firmly on the ground.
The confusion is not carelessness. These words come from operational systems built for airline staff, where each one has a precise trigger, and they leak out onto public displays with their original meanings intact. Once you know the triggers, a departure board becomes genuinely informative instead of merely stressful.
The core statuses, and what triggers each
Every status is set by an event somewhere in the operational chain. Some are set by a human, some by a sensor on the aircraft, and some by a clock.
| Status | What actually triggers it | Should you worry? |
|---|---|---|
| Scheduled | The published timetable, nothing more | No. It means nothing has happened yet |
| Estimated | Operations has revised the expected time, in either direction | Only if it is later than scheduled |
| Gate open / Boarding | An agent opened the flight in the departure control system | No |
| Final call / Gate closing | A countdown to the door closing, often automatic | Yes, if you are not there |
| Departed / Off blocks | The aircraft moved away from the stand | No, but it is not airborne yet |
| En route / Airborne | Wheels left the runway, or the transponder reported airborne | No |
| Landed / On blocks | Touchdown, then arrival at the stand | No |
| Delayed | A revised time beyond a threshold, typically 15 minutes | Yes, and check the cause |
| Diverted | The aircraft is going somewhere other than the filed destination | Yes, but it is usually precautionary |
| Cancelled | The flight will not operate at all today | Yes. Act immediately |
Why estimated and delayed are not the same word
An estimated time is simply the operation's current best guess, which replaces the scheduled time the moment anyone has better information. It can be earlier than scheduled. A flight with a light load and a good tailwind will happily show an estimated arrival twenty minutes ahead of the timetable, and nobody calls that an early.
Delayed is a threshold judgment layered on top. Most systems only apply the word once the revised time exceeds the schedule by a set margin, commonly fifteen minutes, which is also the cutoff used for on-time performance statistics in the United States and much of Europe. This is why a flight can quietly slide from 19:20 to 19:33 without ever being labelled delayed. The airline is not hiding anything; it is applying the same fifteen minute rule its performance figures use.
Estimated is a forecast. Delayed is a verdict. A board can show the first for an hour before it admits the second.
The four times every flight has
Operationally, a flight has four timestamps, and public displays mix them freely.
- Off blocks is when the aircraft is pushed back from the stand. This is the time airlines are measured on, which is why Departed can appear while you are still taxiing past the terminal.
- Wheels up is the actual takeoff. On a congested evening the gap between off blocks and wheels up can exceed forty minutes.
- Wheels down is touchdown, which is the moment most trackers switch a flight to landed.
- On blocks is arrival at the parking stand, which is when the door can open. A flight can be officially on time at the runway and twenty five minutes late to a gate that is still occupied.
Block time, the number airlines schedule against, runs from off blocks to on blocks and therefore includes all the taxiing at both ends. That is why a two hour flight over a distance a jet crosses in ninety minutes is not padding or dishonesty, and it is the same reason two flights covering identical distance rarely share a scheduled duration.
Diverted, returned and cancelled
Diverted means the aircraft is landing somewhere other than its filed destination. It sounds alarming and is usually mundane: fog below minimums at the destination, a medical issue on board, an airport closing for a runway inspection, or fuel reserves reaching the point where the crew must commit. Crews plan alternates before departure precisely so this decision is routine rather than dramatic.
Return to stand and air return are separate cases. The first means the aircraft never left the ground; the second means it took off and came back, most often for a technical indication that is safer to resolve on the ground. Neither implies danger, and both usually end with the same aircraft or a replacement leaving later.
Cancelled is the only status that should make you move immediately. Seats on alternative flights are allocated in the order people ask for them, and the passengers who rebook first are the ones who were already watching. Our guide to overbooking and your rights covers what you are owed when it happens.
Did you know?
Trackers derive status from the aircraft itself rather than from an airline system. The transponder reports whether the aircraft is on the ground, so a tracker can show a flight as airborne before any airline system has caught up, and can show it still on the ground when the board proudly says departed.
When the board and the tracker disagree
They are answering different questions. The airline is reporting its intention and its official record. The tracker is reporting radio broadcasts from the aircraft. When they conflict, the aircraft is the more reliable witness about where it is, and the airline is the more reliable witness about what it plans to do next.
Use them together. If the board says on time but no aircraft has arrived at your gate, believe the empty stand. If the tracker shows your aircraft airborne inbound but the board still says scheduled, believe the tracker and start walking to the gate. Reading a flight tracker map covers the symbols and altitude readouts that fill in the rest.
Key takeaways
- Estimated is a revised forecast and can be earlier than scheduled; delayed is a threshold, usually fifteen minutes.
- Departed means off blocks, not airborne. The two can be forty minutes apart.
- Airlines are measured gate to gate, which is why block times look slow.
- Diverted is nearly always precautionary and planned for before departure.
- Cancelled is the one status that demands immediate action.
- When board and tracker disagree, trust the aircraft about position and the airline about intent.
The two-character codes airlines use among themselves
Behind the public vocabulary sits a second, far more precise one. Airlines record the reason for every delay using standardised numeric and alphanumeric codes defined in industry handling manuals, and those codes are how the operational world actually talks about what went wrong.
The scheme groups causes into families: passenger and baggage handling, cargo and mail, aircraft and ramp handling, technical faults, damage, operations and crewing, weather, air traffic flow management, and reactionary delay meaning a delay inherited from a previous leg. Reactionary delay is consistently one of the largest categories in European reporting, which is the same phenomenon as the American late-arriving aircraft bucket wearing different clothes.
You will occasionally see one of these codes leak into a customer-facing channel, in an app's detail view or in an agent's explanation. It is worth knowing that when an airline attributes a delay to a specific code, that attribution is a formal record used for performance analysis and sometimes for cost allocation between the airline and its ground handler, not an improvised excuse.
The codes also explain a common frustration. A single departure can carry several delay reasons, and only the dominant one is usually communicated. A flight held for a late inbound, then further delayed by a slot restriction caused by weather elsewhere, will often be summarised to passengers as one thing. Both were real; the board had room for one.
The gap between the internal language and the public one is why tracking the aircraft yourself, as covered in how to check if your flight is delayed, gives you a clearer picture than any status word can.
Frequently asked questions
Does estimated mean my flight is delayed?
Not by itself. Estimated simply means operations has revised the expected time, and that revision can be earlier than the schedule. It only indicates a delay when the estimated time is later than the scheduled one, and most systems only apply the word delayed once the gap exceeds about fifteen minutes.
Why does the board say departed when the plane is still on the ground?
Because departed usually means off blocks, the moment the aircraft was pushed back from the stand. Taxiing to the runway can take a long time at a busy airport, so a flight can be officially departed and still twenty minutes from takeoff.
Is a diverted flight dangerous?
Almost never. Diversions are overwhelmingly precautionary: weather below landing minimums, a medical issue on board, a closed runway or fuel reserves reaching a planned decision point. Crews nominate alternate airports before every departure precisely so this is a routine decision.
What is the difference between wheels up and off blocks?
Off blocks is pushback from the stand; wheels up is the actual takeoff. Airlines are measured on off blocks, which is why the official departure time can be well before the aircraft leaves the ground.
Why is my flight not showing any status at all?
Boards typically only display a flight within a few hours of departure. Before that window the flight exists in the schedule but has no operational status, because nothing has happened to it yet.
Status words are a compressed language written for people who already know the system. Once you can expand them, the board stops being a source of dread and becomes what it was always meant to be: a running commentary on where a large amount of metal currently is, and when it plans to move. Watch it happen on the live map.
