The fan shop is the new final assembly

For twenty years the joke in airline planning was that the factory date was a rumor and the interior-completion date was the truth. The joke has moved. At Northline Engines’ principal shop, a full visit on the fan that powers the newest single-aisles is averaging ninety-six days, four longer than the figure the company was still quoting in July. The airframe those engines belong to is, in several cases, already painted.

The work inside the ninety-six days is not mysterious. Blades that flew a hard life in hot-and-high conditions are coming in for a heavier restoration than the early fleet plan assumed. A coating process that was meant to be a parallel task is a queue. Northline has hired. The new hires are not yet the people who sign the blade.

Airlines have responded in the only way a planner can. They are reserving shop slots the way they used to reserve delivery slots, eighteen months out, with deposits that would once have seemed absurd for maintenance. A slot, in this market, is a part.

None of this is a reason to ground the fleet that is already flying. It is a reason the fleet that is painted and engineless will stay on the ground longer than the livery on the tail suggests. Passengers do not see a shop visit. They see a schedule that was supposed to grow and, quietly, did not.