Ryanair:

10 flights a day. 25 minutes on the ground between each one. €65m in the air.

Ryanair's 89% on-time figure is not what you think it is.

Most people read it as a customer promise.

Ryanair reads it as a production schedule.

The plane is a factory. It does 10 runs a day. Each window on the ground is 25 minutes. Less time than it takes to get a coffee at Heathrow.

No slack built in. No room for anything to go wrong. Something always goes wrong. A 20-minute slip at 7am doesn't stay at 7am. It travels with the aircraft. Through rotation three, five, seven, nine.

By the time the same plane lands for the last time that day, passengers sitting in a delay at 9pm are still carrying a problem that started before most of them had breakfast.

Ryanair runs more flights per aircraft than any other carrier in Europe, so each slip compounds across more rotations than a rival running four or five daily cycles would face.

89% is not measuring whether your journey was comfortable.

It's measuring whether an asset worth €65m completed its production run.

Every airline publishes on-time performance.

Ryanair publishes the same number with the same label.

When you see that figure for any carrier, the question worth asking is: what is actually being measured here?

A passenger experience target or an asset efficiency score?

The answer tells you more about the business than the number.