Boeing has won approval from U.S. regulators for a fix to an electrical grounding issue that had affected about 100 737 MAX airplanes.

An FAA official confirmed the news.

Boeing sent two bulletins to airlines on Wednesday (May 12) regarding the fixes.

The announcement is a relief for U.S. air carriers that have been waiting to get the planes back into service before the summer travel season.

Particularly as travel demand begins to improve.

The FAA administrator said he was fully confident in the safety of the MAX.

It was approved to return to service in November 2020 after being grounded for 20 months following two fatal crashes that killed 346 people.

The electrical issue reportedly emerged after Boeing changed a manufacturing method as it worked to speed up production of the jetliner.

The issue was linked to a backup power control unit in the cockpit on some recently built airplanes.

The problem, which also halted delivery of new planes, was then found in two other places on the flight deck.

The top three U.S. 737 MAX operators - Southwest Airlines, American Airlines and United Airlines - removed more than 60 jets from service after the notice from Boeing.