Boeing Software Issues Ground New 737 MAX Deliveries Amid FAA Review

Two major US airlines, United and Southwest, are refusing deliveries of new Boeing 737 MAX aircraft due to software issues. The problem affects vertical navigation (VNAV) which helps manage climbs and descents along a programmed flight path.

The issue can occur if pilots call off a landing and revise the flight plan while preparing to try again. In certain circumstances, VNAV may even switch off, leaving pilots to manually manage the aircraft's vertical path.

Boeing informed operators about the problem in August and shared its findings with the Federal Aviation Administration (FAA). The manufacturer is now working on a permanent software fix.