Airlines around the world sped Boeing’s 737 Max into service, eager to capitalize on its efficient engines, writes The New York Times (April 12, 2019). Some low-cost carriers built new routes around the Max, which could travel farther on less fuel than its predecessor. But with the Max grounded following two deadly crashes, the airlines that rely on its planes are scrambling to adjust, and the costs are mounting.

Major carriers, including Southwest, American and United, have canceled thousands of flights. Boeing has slowed production of the Max and stopped deliveries, stockpiling the finished planes in Seattle. And there is no firm timetable for the return of the Max. (One industry analyst predicted a return between August and November).

American, which operates 24 Max planes and has 76 more on order, canceled 1,200 flights in March, and said it would have to cancel an average of 115 flights a day through August. American has been trying to spread the effects throughout its system, pulling aircraft from routes with multiple flights a day to service flights normally operated by a Max. Southwest, which has 34 Max jetliners and was operating about 140 flights a day with the plane before the grounding, has adjusted its schedule through August. United, which has 14 Max planes, expected 130 related cancellations this month.

Other airlines that don’t have many spare planes to use in a pinch are feeling the impact. At WestJet, a Delta partner, the rest of the fleet has to fly more with less downtime. Says the VP: “We’re flying the airplanes hard. That puts a lot of strain on the organization.” India’s SpiceJet, a big low-cost carrier, said it plans to rent 16 older Boeing 737-800 jets to partly fill the gap from grounding its 13 MAX planes and the 21 more due to arrive this year.