The agency didn't offer an estimated time frame for approval.

This long wait wasn't entirely unexpected. Leaks hinting at tentative approval warned that Boeing might have to make last-minute changes, and even an ideal update schedule would have airlines waiting a while to deploy the update to their fleets. Still, the FAA's statement is a reminder that the parties involved don't want to take any chances with the 737 Max's stall system, and that this saga is unlikely to end for a long while.