# Why the tracker and the airline disagree

> A tracker usually times the wheels and an airline times the gate. Why they can differ by half an hour, and which one to believe for what.

By Derek Johnson. Updated Nov 7, 2026. Source: https://skycapapp.com/articles/overhead/why-tracker-and-airline-disagree/

They're usually timing different things. A tracker says "landed" when the wheels touch. An airline's "arrived" means the plane reached the gate. The gap is taxi-in, 7 minutes at the median US airport and 18 at O'Hare, and it can be more than 50 at O'Hare on a bad evening.

Everyone in aviation splits a flight into four moments, and the arguments mostly come from people quoting different ones.

| Moment | What happened | Who knows first |
|---|---|---|
| Out | The plane left the gate | Airline |
| Off | The wheels left the runway | Anyone watching it climb |
| On | The wheels touched the runway | Anyone watching it land |
| In | The plane parked at the gate | Airline |

US airlines report these to the government. Under 14 CFR 234.4, a flight's arrival and departure times are the times it reached and left the gate. A gate arrival counts when the pilot sets the parking brake at the gate, with the door opening as the fallback. Wheels-off and wheels-on are reported as separate items.

So the schedule you booked is a gate schedule. The FAA's glossary agrees for scheduled airlines: an ETA is the time the flight is estimated to reach the gate. A plane that touches down at 7:10 for a 7:05 arrival is on time if it parks before 7:20. One that touches down at 7:05 at O'Hare can park at 7:30 and count as late. "Late" means gate time, 15 minutes or more after the published arrival.

## The common mismatches

If the tracker says landed and the airline says in flight, the plane is probably on the ground and taxiing. An airline's app may be waiting for the gate event, or may refresh more slowly. Give it several minutes at a big airport.

Sometimes a tracker says landed and the plane hasn't. Some apps call a flight landed when its signal disappears near the airport, or when the scheduled time passes. Low planes drop out of receiver range all the time. I've made this mistake myself: if you only watch for a position vanishing, you'll land a plane that's still on approach.

An airline can also say arrived while the plane is still moving, when an estimated gate time sits on screen as if it were a fact. The reverse happens too. A gate event can be late, wrong or missing, so the arrival may post after you've left the plane.

"Departed" on an airline's screen usually means pushed back from the gate. The plane can be in line for the runway for a long while after that, and a tracker that times take-off will show a later start.

The flight numbers may not match either. Trackers often show the operating airline's call sign, and airline sites show the number you bought. A flight sold by Delta can appear under the regional carrier flying it.

## Which to believe for what

For "is it in the air" and "has it touched down", believe a tracker that has seen the plane. Position reports come from the aircraft itself.

For the gate, the belt, the boarding time and anything about your ticket, believe the airline. The airline owns those facts, and a tracker has them second-hand. Before you change a plan, check the airline's app. That goes double for a cancellation or rebooking.

For "when will they be outside", neither one answers it. Landing starts the clock, and [what's left depends on the row, the bag and the walk](/articles/landing/how-long-from-landing-to-curb). A long stretch between on and in is explained in [why O'Hare takes 18 minutes](/articles/landing/taxi-in-ohare-vs-midway).

## "Should have landed" is the honest phrase

When nobody has seen the plane land, the only honest statement is an estimate. I'd rather an app said "should have landed about 6:48" than "landed", and I've tried to hold to that. A clock passing a scheduled time isn't evidence of anything. On a diverted flight, it's actively wrong.

If you've got a dot that stopped moving short of the runway, or a flight that says landed when the person hasn't called, [here's how to read what a tracker is telling you](/articles/overhead/how-flight-trackers-work). Abbreviations are in [the flight tracking word list](/articles/overhead/flight-tracking-words).

> When you're waiting on a flight, Skycap says "should have landed" until something has seen it land, then gives the time. It keeps the wheels-on time and the gate time apart, and every estimate reads as one. [How it works](/app/how-it-works)

## Sources

- [14 CFR 234.4, reporting of on-time performance](https://www.law.cornell.edu/cfr/text/14/234.4)
- [14 CFR 234.2, definitions](https://www.law.cornell.edu/cfr/text/14/234.2)
- [FAA Pilot/Controller Glossary, E](https://www.faa.gov/air_traffic/publications/atpubs/pcg_html/glossary-e.html)