Boeing is sticking with its assumption the Boeing 787 MAX will return to service to in the fourth quarter of this year despite a request from regulators that it resubmit documentation relating to the jet’s software. The manufacturer confirmed it had been asked to resubmit some technical documentation relating to changes it is making to the MAX flight control software aimed at preventing a repeat of two fatal accidents. The airliner has been grounded since March after software known as MCAS was implicated in the tragedies involving Indonesia’s Lion Air and Ethiopian Airways. The changes were among issues flagged during a weekend meeting between US Federal Aviation Administration and European Union Aviation Safety Agency officials, according to Reuters. READ: Ryanair expects further delay in MAX deliveries to cut growth A Boeing spokesman told AirlineRatings that the company had provided technical documentation to the regulators as part of the software validation process. “The documentation was complete, and it was provided in a format consistent with past submissions,’’ he said. “Regulators have requested that the information be conveyed in a different form, and the documentation is being revised accordingly. “While this happens, we continue to work with the FAA and global regulators on certification of the software for the safe return of the MAX to service.” There has been much speculation about when the MAX will get back in the air and US carriers have taken it out of their schedules until early next year. The European regulator, which is also conducting an assessment of the changes to the software and training has also indicated it doesn’t expect to make a decision before then. The Boeing spokesman said the current assumption involved a return to service in the fourth quarter of 2019. “This assumption reflects our best estimate at this time, but actual timing of return to service could differ from this estimate,’’ he said. “We continue to work with civil aviation authorities on the 737 MAX’s safe return to service, and these authorities will determine the timing of return to service.”