737 Max cancellations means summer vacation could be more stressful and expensive than travelers planned, due to fewer spare airplanes. (Apr 24) AP, AP

Boeing said Thursday that it has completed its software fix on the 737 Max, a key step toward getting the grounded jetliner back in the air after two deadly crashes.

But the jet still isn’t likely to be back in service for months. It now faces tests and certification by the Federal Aviation Administration and other agencies around the world.

The software update focuses on the automated system designed to counteract a tendency for the plane’s nose to point up due to heavier engines mounted in a more forward