Metro officials said Thursday that construction of the Silver Line’s second phase could be complete in November, paving the way for a possible opening of the long-delayed project during the first part of next year.

Construction of the nearly 11-mile extension would bring rail service from the Wiehle-Reston East Metro station to Dulles International Airport and through to Ashburn. The latest estimate for opening comes after the project has been plagued by issues, including misaligned track and weak concrete panels, that have delayed its opening by nearly two years.

Andrew Off, Metro’s vice president of the Rail Operations Control Center and Strategic Transformation, told Metro board members that the transit agency was told the $5.8 billion project is scheduled for “substantial completion” in November, at which point Metro could take ownership after it determines the extension is ready for operations. Capital Rail Constructors is handling construction, which is being overseen by the Metropolitan Washington Airports Authority.

While Metro officials did not give board members an expected opening date, transit officials repeatedly have said they could test for about two months before taking possession of phase two, then another three months to open the line, which includes six new stations.

“The airports authority still forecasts fourth quarter of this calendar year as declaring substantial completion,” Off said.

Keith Couch, project executive for Capital Rail Constructors, said in a statement that the company is targeting substantial completion for the last quarter of this year. MWAA officials, however, said Thursday they could not predict a timeline for that designation.

MWAA spokeswoman Marcia McAllister said the authority is waiting for results of testing of the automated train control system scheduled in late October — a test that will require the temporary closure of the Wiehle-Reston East station — to “tie in” both phases of the Silver Line.

“At this point we do not have a completion date planned,” she said.

The previous date by which the project was to have met “substantial completion” was Labor Day. But MWAA scuttled that projection because it said upcoming tests were essential.

Off said MWAA began testing trains and the train control system late last month, which he called a “major milestone.”

“Once substantial completion is declared, we enter an undefined — in time — period called operational readiness testing,” Off said. “This is our opportunity to complete and witness and document all tests.”

Although the project’s contractor has estimated the testing period would last about 60 days, Off said the transit agency can take the time it needs to make sure the extension is ready to operate. Once satisfied with testing, Metro would take custody and control. The transit agency would need about 90 days to make final preparations necessary to open the extension.

Joseph Leader, Metro’s chief operating officer, said hiring is underway to staff the extension.

By the end of August, Metro had put 154 employees through orientation. Hiring, Leader said, is accelerating as the transit agency seeks to fill 468 positions between now and the extension’s opening.

Metro officials said two significant construction issues are unresolved between Metro and MWAA, and Off said he and Leader are meeting with the airports authority twice a week to address them. They include a clearance issue within elevator machine rooms and a deficiency with a train turntable at a service and inspection building, both at the Dulles rail yard.

Metro board members on Thursday also heard results from a two-year study they commissioned before the coronavirus pandemic to find solutions to crowded stations on the Blue, Orange and Silver lines.

The study evaluated six options to alleviate crowding and address growth, with Metro planners saying a new Blue Line route with a second Rosslyn station was the best option. The line, estimated to cost up to $25 billion, would require a new Potomac River tunnel and create a station in Georgetown, with stops at Union Station and National Harbor.

“Addressing Metro’s core capacity issues is critical to meeting the growing demand of Virginia’s Metro riders,” said Jennifer Mitchell, director of the Virginia Department of Rail and Public Transportation.

Metro General Manager Paul J. Wiedefeld said regardless of the ranking of options, “no project has been selected at this stage of the study.” Board members reviewed the results of the study but took no votes.

The biggest concern raised was the price tag, much of it tied to building a new tunnel between Rosslyn and Georgetown. Metro Board member and Loudoun County Supervisor Matthew F. Letourneau (R-Dulles) said Virginia cities and counties are interested in expansion but would like to bring down the cost.

“Can we have an alternative that kind of narrows the scope a little bit?” he asked Metro planners. “When you start floating projects that have $20-plus billion-dollar price tags, they become sort of so impossible that I worry momentum won’t be there.”

Metro also swore in three new board members representing the federal government. They include Kamilah Martin-Proctor, chair of the Washington D.C. Commission on Persons with Disabilities; and Sarah Kline, a consultant and former Metro director of policy and government relations, who has also worked for Transportation for America and Reconnecting America. Bryna Helfer, assistant county manager and director of communications and public engagement for Arlington County, was named an alternate.

They replaced Steve McMillin, Devin Rouse and alternate Anthony E. Costa.

Lori Aratani contributed to this report.