What one late aircraft costs, and how much of it you can get back
Alaska runs roughly 220 aircraft through Seattle on an ordinary day, and every one of them needs a gate. When a flight arrives late, the gate it was going to use is still occupied — so the aircraft behind it waits, and the delay spreads.
ALTO takes a real day, lets you break it, and prices the damage. Then it re-solves the whole day's gate plan from scratch and shows how much of that damage careful reassignment recovers.
Pick a day
Every bar is one real day of 2023. Click one to load it.
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Why the holidays are not the peak
Thanksgiving weekend sets passenger records, but a gate is taken by an aircraft, not by the people in it. Holiday peaks are fuller aeroplanes; summer peaks are more aeroplanes. Alaska schedules its heaviest flying in late July and August, which is what this chart shows — and Thanksgiving Day itself is the quietest day of the year here.
Break something
Delay an aircraft, take a stand out of service, or argue with the cost assumptions. Nothing here is destructive — run it as many times as you like.
Every aircraft listed is a real Alaska tail number flying its real schedule that day.
Airlines for America put the cost of a minute of delay at $98.41 in 2025. Move it if you disagree.
How much lateness carries to the aircraft's next flight. An assumption, not a published figure — which is why you can move it.
The integer program instead of the network flow: about 20 seconds instead of 1, for 9% less passenger walking. Identical gate count — proven on 16 days.
Alaska rents C, N and D. The S stands are common‑use — billed $552.89 every turn they are used, so the optimizer only reaches for them when it must.
See what it cost
The same day run three times: as scheduled, after your disruption with nobody reacting, and after the whole gate plan is re-solved around it. The gap between the second and the third is what the model is worth.
Nothing broken yet. Delay an aircraft above, then press Run — it takes about a second.
These are fees, not the cost of running an airline. ALTO prices exactly three things — delay, aircraft parking and towing, and common-use gate charges — because those are the ones a gate plan changes. Fuel, crew, maintenance, landing fees and the rent on Alaska's own gates are all excluded: real money, but the same whichever plan you pick.
The big figure is the difference the disruption made, not a total. The normal day's fees are the first row of the table below.
Where these numbers come from
Delay is priced at the rate in the slider above. Towing is $100 a movement, and a common-use stand is $552.89 a turn. That is the whole bill — every figure is a charge somebody actually invoices Alaska for, which makes each one a floor rather than a guess.
Gate use is deliberately not priced. Idle gate time costs an airline nothing directly: rent on a preferential gate is fixed by the lease and does not move when the plan changes. An earlier version did price it, and the result was a model that thought closing three gates saved money. It is reported as a utilisation percentage instead.
| Run | Delay | Gate use | Towing | Common use | Fees | Gates |
|---|---|---|---|---|---|---|
| Run a scenario to fill this in. | ||||||
The day, gate by gate
One row per gate, time running left to right. Each bar is one aircraft holding one gate — hover any of them for the tail number and where it is going.
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How to read this, and why it runs past midnight
Read a row across to see one gate's whole day: back-to-back bars mean a hard-worked gate, gaps mean capacity standing empty. Read a column down to see how much of the airport is in use at once — the tallest column is the day's peak, and that number is what decides how many gates Alaska needs.
The chart runs into the following morning on purpose. An aircraft that lands at 11pm and departs at 6am is one continuous gate visit, and cutting it at midnight would hide half of it. About 16,870 visits in 2023 cross midnight this way.