Europe’s aviation regulator doesn’t expect to give the Boeing 737 MAX the green light to return to service until early next year and expects to make a decision sometime after its  US counterpart. European Union Aviation Safety Agency  (EASA) head Patrick Ky told Reuters that flight tests by European pilots were expected to take placed mid-December with January the earliest date for a return to service. He also said there would a gap of weeks rather months between a US decision to clear the grounded planes and one in Europe. READ: Boeing says MCAS pilot messages involved simulator still under test. "For me, it is going to be the beginning of next year if everything goes well,’’ Ky told the news agency. “As far as we know today, we have planned for our flight tests to take place in mid-December which means decisions on a return to service for January, on our side.” Ky said EASA would co-ordinate as closely as possible with the US Federal Aviation Administration and any delay would be due “mostly to process or administrative technicalities”. The comments dash hopes by airlines of a co-ordinated approach to the grounding by regulators. It remains unclear when the FAA will give the go-ahead to the MAX but Boeing officials have been saying they expect a decision by year’s end. A number of US carriers have taken the MAX out of their schedules while they wait for the green light but they can adjust those plans if it happens sooner. However, airlines have cautioned it will take several weeks to get the grounded aircraft checked and operational again. Reuters said Ky made the comments before emails between two Boeing pilots about problems with MCAS on a MAX simulator became public. The emails plunged Boeing into a fresh crisis with its shares falling amid downgrades by analysts over ongoing uncertainty about the return to service. Boeing chief executive Dennis Muilenburg, who recently lost his chairman's role, is due to address a Congressional committee later this month.