# Flight tracking words: wheels up, in-blocks, EDCT, ETA

> The terms trackers and airlines use, in plain English, with the regulators' definitions where they exist.

By Derek Johnson. Updated Nov 7, 2026. Source: https://skycapapp.com/articles/overhead/flight-tracking-words/

"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](/articles/overhead/why-tracker-and-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](/articles/landing/taxi-in-ohare-vs-midway) |
| 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](/articles/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](/articles/overhead/how-to-read-a-flight-path) |
| 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](/articles/overhead/whats-that-plane-overhead) |
| 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](/articles/overhead/how-flight-trackers-work) |

## 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](/articles/landing/how-long-from-landing-to-curb) |
| Passport control | The border booth when you land in the US from abroad. [Waits, by terminal](/articles/landing/passport-control-wait-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.


## Sources

- [FAA Pilot/Controller Glossary, D](https://www.faa.gov/air_traffic/publications/atpubs/pcg_html/glossary-d.html)
- [FAA Pilot/Controller Glossary, E](https://www.faa.gov/air_traffic/publications/atpubs/pcg_html/glossary-e.html)
- [FAA Pilot/Controller Glossary, F](https://www.faa.gov/air_traffic/publications/atpubs/pcg_html/glossary-f.html)
- [FAA Pilot/Controller Glossary, G](https://www.faa.gov/air_traffic/publications/atpubs/pcg_html/glossary-g.html)
- [FAA Pilot/Controller Glossary, T](https://www.faa.gov/air_traffic/publications/atpubs/pcg_html/glossary-t.html)
- [14 CFR 234.2, definitions](https://www.law.cornell.edu/cfr/text/14/234.2)
- [14 CFR 234.4, reporting of on-time performance](https://www.law.cornell.edu/cfr/text/14/234.4)
- [FAA Aeronautical Information Manual, 4-5-7, ADS-B services](https://www.faa.gov/air_traffic/publications/atpubs/aim_html/chap4_section_5.html)