FILE PHOTO: A Boeing 737 MAX airplane lands after a test flight at Boeing Field in Seattle

A Boeing 737 MAX airplane lands after a test flight at Boeing Field in Seattle late last month.

SEATTLE — Boeing has been anxious to get its 737 MAX cleared to fly again so it can start delivering what used to be a key moneymaker, but the latest schedule information from the Federal Aviation Administration (FAA) — including a lengthy public comment period — suggests the process will be stretched a bit further.

The FAA said Tuesday it will soon formally publish the proposed design changes to the Boeing 737 MAX flight control system as well as proposed new pilot procedures, and will allow 45 days for public comment ahead of clearing the jet to fly passengers again.

While this is a clear signal that federal approval for the 737 MAX to return to service in the U.S. is approaching, a person familiar with the steps ahead said it pushes the likely date for a go-ahead to mid-October, some 19 months after the plane was grounded.

Previously, Boeing had privately indicated that the jet might be ungrounded in September. Some within the company had hoped the FAA might issue clearance for the MAX that took effect immediately, with public comment possible afterwards.

But given the intense scrutiny of the jet’s re-certification and continued public suspicion of the MAX after two crashes, that would have invited accusations of predetermining the outcome, and even potential legal action. The FAA has opted for the standard process, requiring a public comment period ahead of the decision.

“In keeping with our commitment to remain transparent, the (notice) will provide 45 days for the public to comment on proposed design changes and crew procedures to mitigate the safety issues identified during the investigations that followed the Lion Air and Ethiopian Airlines accidents,” the agency said in a statement.

Typically, such an FAA invitation for public comment draws responses from interested parties in the industry, such as airline operators, pilot unions and engineering experts.

In this case, given widespread public concern about the jet’s safety, a wider range of comments is likely, including from the families of the 346 people who died in the two crashes and perhaps from the Congressional committees that have been investigating the accidents.