United Airlines has begun asking its pilots to take unpaid leave after reducing flight hours in response to the delayed delivery of new Boeing planes. 

A memo from the Air Line Pilots Association union informed United pilots that the airline was offering unpaid time off and short-term leaves in May but was not making them mandatory, as first reported by CNBC.

United spokesperson Leslie Scott said: “Due to the recent delays in Boeing deliveries, our forecasted (flight hours) have been reduced and we are offering our pilots voluntary programs for the month of May to reduce excess staffing.” 

The move comes only a month after the airline revealed it would be slowing pilot hires and pausing new hire classes between May and June as it adjusts its expectations for the year. 

CEO Scott Kirby also earlier said that the airline was now working with an alternative plan that did not include the 277 MAX 10 aircraft it has on order, 80 of which were supposed to have been delivered this year. 

As a result, the airline has reportedly been working with Boeing to convert some of the orders to MAX 8 or MAX 9 aircraft, and is also talking to rival manufacturer Airbus about acquiring further A321neo planes. 

The decisions by United are part of the industry-wide knock-on effects of Boeing’s ongoing quality control and production struggles which have slowed its 737 MAX production line and brought extra scrutiny to the certification of the MAX 10. 

After years of struggles, partially affected by the global groundings of 737 MAX aircraft following the two fatal crashes involving the aircraft in 2018 and 2019, the MAX 10 had been expected to be certified by early 2024 but only began flight testing in November 2023. 

Additionally, the manufacturer has been criticised by the industry after the Federal Aviation Administration (FAA) and National Transportation Safety Board (NTSB) found significant issues with its quality control procedures during investigations after the door plug blow out of a 737 MAX aircraft in January, leading CEO Dave Calhoun to step down from his position.