“Wheels” words are about the runway, “blocks” and “gate” words are about the parking spot, and most airline times are gate times. Where a regulator defines a term, I’ve used its meaning. Where it’s airline shorthand, I’ve said so.
The four moments of a flight
Airlines record these four and call them OOOI: out, off, on, in. Blocks are the wheel chocks.
| Moment | Also called | What it means |
|---|---|---|
| Out | Off-blocks, pushback, gate departure | The plane leaves the gate. Your ticket’s departure time means this |
| Off | Wheels up, wheels-off | The plane leaves the runway. The FAA’s glossary calls this departure time, which is a trap, because your ticket doesn’t |
| On | Wheels down, wheels-on | The plane touches the runway. Most trackers mean this by “landed” |
| In | In-blocks, gate arrival | The plane parks. US reporting rules count it when the pilot sets the parking brake. Your arrival time means this |
Why the tracker and the airline disagree follows from that table.
Times and estimates
| Term | Meaning |
|---|---|
| Actual time | A recorded event. Anything else is an estimate |
| Block time | Gate to gate, out to in. Schedules are built on this, with room for taxiing |
| Air time | Wheels-off to wheels-on |
| ETA | Estimated time of arrival. For scheduled airlines, the FAA defines it as arrival at the gate. Trackers sometimes use it for landing, so check |
| ETE | Estimated time en route, the flying time from lift-off to touchdown |
| On time | In US reporting, arriving less than 15 minutes after the published arrival time. A flight 14 minutes late is on time |
| Taxi-in | Wheels down to the gate. National median 7 minutes, with a wide spread |
| Taxi-out | Gate to wheels off |
Why you’re waiting
| Term | Meaning |
|---|---|
| EDCT | Expect Departure Clearance Time. The runway release time given to a flight in a traffic management program. If you have one, the airline didn’t choose that delay |
| Ground stop | Aircraft that meet set criteria stay on the ground, for example all departures to one airport. More in Why it’s late |
| Ground delay program | A traffic management process that holds aircraft on the ground to limit airborne holding |
| Gate hold | Keeping a plane at the gate or another ground spot when departure delays run past 15 minutes |
| Holding | Flying a racetrack in the air until there’s room to land. How to spot one |
| Diverted | Required to land somewhere other than the scheduled destination, for reasons beyond the pilot’s or airline’s control |
In the air
| Term | Meaning |
|---|---|
| ADS-B | Automatic Dependent Surveillance-Broadcast. The plane sends its position about once a second. More here |
| Transponder | The radio on board that answers ground radar. It often carries ADS-B too |
| Squawk | A controller’s word: set the transponder to a four-digit code |
| Call sign | The name a flight uses on the radio. It may not match your flight number, especially on a regional carrier |
| Flight level | Altitude at a standard pressure setting, in hundreds of feet. FL350 is 35,000 feet on the altimeter |
| Step climb | Airline term for moving up a level in cruise as fuel burns off |
| Top of descent | The point where the plane begins its initial descent |
| Assumed path | Tracker term for an estimated position with no report behind it. Why that happens |
On the ground afterwards
| Term | Meaning |
|---|---|
| At the curb | No regulator’s term. It’s how I describe the moment you’re outside the terminal. How long that takes |
| Passport control | The border booth when you land in the US from abroad. Waits, by terminal |
Questions people ask
What does in-blocks mean?
The plane has parked at the gate. US reporting rules count gate arrival when the pilot sets the parking brake, with the door opening as a fallback.
What is the difference between wheels up and departure time?
Departure time on your ticket is when the plane leaves the gate. Wheels up is when it leaves the runway, after the taxi out.
What does EDCT mean on my flight?
An Expect Departure Clearance Time is a runway release time set by air traffic management. It's why a plane can be ready and still wait.
Does ETA mean landing time?
For a scheduled airline, the FAA defines ETA as the time the flight is estimated to reach the gate. Landing comes before that.
What counts as a late flight?
US rules count a flight as on time if it arrives less than 15 minutes after its published arrival time, measured at the gate.