John Potter, then-postmaster general and chief executive officer of the United States Postal Service, testifies at a Senate Appropriations Committee hearing March 18, 2010. (Andrew Harrer/BLOOMBERG)

The governing body of two of the Washington area’s main airports is expected to tap the former head of the U.S. Postal Service on Wednesday as its next chief executive, according to sources familiar with the search.

John E. “Jack” Potter, the recently retired postmaster general, has emerged as the leading candidate to take over the Metropolitan Washington Airports Authority, which oversees Reagan National and Dulles International airports and the multibillion-dollar project to extend Metrorail to Dulles and Loudoun County.

Potter, who retired in December after a 32-year postal career, would take the top job at a tumultuous time for the airports authority. The authority’s board has been skewered by local, state and federal leaders for its management of the second phase of the 23-mile Metro project and for its initial handling of the search for a new chief executive.

Board Chairman Charles D. Snelling said he could not comment on the search until after the board’s formal vote, scheduled for Wednesday morning. Potter did not return phone messages this week. Other sources familiar with the search spoke on condition of anonymity so they could talk freely about personnel matters.

Potter, 55, would replace James E. Bennett, who announced his retirement more than a year ago after 14 years on the job. E. Lynn Hampton, another veteran of the authority, has held the position temporarily and plans to retire after a new leader is named.

The authority is a self-supporting entity with 1,400 employees and a $1.9 billion budget. Potter’s biggest challenges could be political. The authority’s board is under fire for the rising cost of the Metrorail project, including its preference for building an underground station at Dulles. Local leaders, who are helping pay for the project, have urged the board to reverse course and back a less expensive aboveground station that is not as close to the terminal.

Potter would also have to manage a diverse 13-member regional board that includes appointments from the president, the governors of Maryland and Virginia and the District’s mayor.

Although Potter does not have airport management experience, he developed relationships with airlines who ship cargo for the Postal Service. Those who have worked with him said Potter’s leadership of one of the nation’s largest employers would serve him well in a new arena.

FedEx founder and chief executive Frederick W. Smith worked closely with Potter because of the Postal Service’s reliance on the company’s planes to move Priority Mail.

“There are very few people who have managed something as big and complex as the U.S. Postal Service,” Smith said. “I suspect that’s why they’ve got him at the top of their list.”

‘The guy next door’

The son of a postal worker, Potter rose through the ranks of the service, starting as a postal clerk in New York in 1978, before becoming one of the longest-serving postmasters general. He presided over a difficult period for the quasi-government agency as an increasing number of households and businesses have come to rely on e-mail correspondence and online bill-paying services. With declining mail volume and rising retiree health costs, the Postal Service reported an $8.5 billion loss in 2010.

Potter is credited with shrinking the size of the workforce to about 580,000 and with enhancing the reliability of deliveries. But he was constrained by congressional oversight and powerful postal unions. On the Hill, lawmakers rejected his proposals to close thousands of post offices and eliminate Saturday delivery. The month before he announced his retirement, postal regulators rejected a plan to raise first-class postage rates above the rate of inflation.

Anthony Conway, executive director of the Alliance of Nonprofit Mailers, who fought the rate increase, said Potter was an effective leader and tough manager who projected the message that “people better do what he wants.”

“It’s so big and massive that if you don’t have a strong leader at the top, it’s tough to run the place because people have their own agendas.”

Conway said Potter fell short politically when it came to pressing forcefully for sweeping change.

“He was perhaps not as aggressive in pushing back against the constraints both with the unions and congressional interference. There are folks who say he didn’t push hard enough and allowed the constraints to limit how far he could go,” Conway said.

Potter’s background as a rank-and-file postal worker gave him credibility with employees, who viewed him as “the guy next door,” said William Burrus, former president of the American Postal Workers Union.

Burrus, whose union ranks were trimmed by thousands over five years, said Potter could have been more aggressive in trying to increase the volume of mail. But he praised Potter for treating employees fairly.

A troubled search

Potter, a Potomac resident who is married with two children, emerged as the consensus candidate after the airports authority scrapped its initial search. Early in the year, the board was bitterly divided over another front-runner, Nathaniel P. Ford Sr., the outgoing chief of San Francisco’s Municipal Transportation Agency. Questions about Ford’s personal financial troubles that emerged late in the process split the board, with at least one member accusing others of racism for their opposition to Ford, who is black. Potter was not a candidate in the initial search.

The board opted to restart its search this spring, hiring a new executive search firm and enlisting Warner H. Sessions, a new board member from the District, to lead the process. At least four candidates were brought back for a second round of interviews in early June. That group did not include Ford, according to sources close to the search.