Boeing 737 Max jet is expected to return to service in the first quarter of next year in Europe, according to a top aviation regulator, which is a major boost of confidence in the narrow-body aircraft that has been grounded after two fatal crashes. The European Union Aviation Safety Agency (Easa) will likely approve flying Boeing's best-selling plane in January but preparations by national regulators and airlines could push commercial flights by another two months, Patrick Ky, Easa's executive director, said at the agency's annual safety conference in Helsinki on Monday. "If there are training requirements and co-ordination to be done with the EU member states to make sure everyone does the same thing at the same time, this will take a bit of time," Mr Ky said, according to reports. "That's why I'm saying the first quarter of 2020." Boeing has reiterated that it is aiming to return the Max to service by the fourth quarter of this year after making software fixes to the flight control system implicated in the crashes that killed 346 people. Global aviation regulators have said they will conduct their own safety checks on the plane, grounded worldwide since March, causing a rift in the industry about the timeline and steps needed to fly the Max again. Easa will carry out its own set of checks on the plane, including simulator and flight tests, before permitting commercial flights to resume in Europe. Mr Ky told Reuters that European experts have travelled to Iowa to the facilities of Rockwell Collins, which helped develop the Max flight control software with Boeing, to begin an audit of a “reasonably final” software version. “There has been a lot of work done on the design of the software,” Mr Ky said. But he added: “We think there is still some work to be done.” He did not elaborate on the likelihood that regulators will require additional simulator training for Max pilots, which would add more delay and cost for many airline customers, according to Reuters. That decision can be taken only after Easa's own simulator and flight tests, Mr Ky said. “It’s really at the end of the process because it’s much more operational," he said. The European regulator aims to complete a detailed software review by the end of this month, followed by December flight tests “if everything goes well”, he added. The Max grounding has dented Boeing's earnings, disrupted operations for airlines, hurt operators' profit and damaged travellers' confidence in the jet. However, the Max's return to service could pose another problem for airlines: there are concerns about aircraft oversupply as Boeing has continued to produce the plane and is expected to speed deliveries in a bid to clear backlog. The surplus in aircraft flooding the market, combined with worries about a global economic slowdown and fragile growth in travel demand, may make it difficult to absorb the jets, analysts say.