EASA executive director Patrick Ky said on Friday he felt satisfied with the results of changes to the 737 Max, adding that the airplane could resume flying in Europe before the end of the year. Ky told Bloomberg that EASA will soon complete document reviews ahead of a proposed airworthiness directive (PAD) it expects to issue in December, at which point a four-week comment period will begin.

In a written statement, EASA’s communications director confirmed that the agency expected to issue the PAD in December and that it would publish a final airworthiness directive at the end of the public consultation period.

Notwithstanding his apparent endorsement, Ky also told Bloomberg that EASA has asked Boeing to add a so-called synthetic sensor to supplement the airplane’s two angle-of-attack (AoA) sensors. An AoA sensor malfunction in the Max triggered the airplane’s maneuvering characteristics augmentation system (MCAS) to improperly activate in both of the airplanes involved in the fatal crashes that killed 346 people. Ky said he expected the third sensor to become available at around the time of expected certification of the Max 10 late next year.

Ky’s statements come as U.S. regulators continue their review of comments submitted on the Notice of Proposed Rulemaking (NPRM) containing the draft airworthiness directive to return the airplane to service. The NPRM would require updating flight control software with new control laws to prevent erroneous MCAS activation; incorporating new and revised procedures in the airplane flight manual to ensure the flight crew can recognize and respond to erroneous stabilizer movement; installing new Max display system software to alert the pilots if the aircraft’s AoA sensors disagree by a certain amount and indicate a potential failure; and changing the horizontal stabilizer trim wire routing installations to bring them into compliance with the agency’s latest standards. It also would require operators to complete an AoA sensor system test and perform an operational readiness flight before returning each airplane to service.