KEY POINTS
  • U.S. and European regulators have asked Boeing to revise documentation on its proposed 737 Max software fix, the planemaker confirmed.
  • The request further complicated the world's largest planemaker's efforts to return the jet to service by year-end.
  • Boeing had submitted documentation in a key part of an approval process for a 737 Max software upgrade in the wake of two crashes in Ethiopia and Indonesia that killed 346 people.

U.S. and European regulators have asked Boeing to revise documentation on its proposed 737 Max software fix, the planemaker confirmed Wednesday, further complicating its efforts to return the jet to service by year-end.

The world's largest planemaker had submitted documentation in a key part of an approval process, already delayed by months, for a 737 Max software upgrade in the wake of two crashes in Ethiopia and Indonesia that killed 346 people.