Transportation Secretary Brock Adams wrote Washington area officials yesterday that he "could not confidently approve" any federal money to build a subway line through Wheaton until that line's need, cost and design are justified to him in a restudy.

Additionally, Adams said in an interview, he regards local approval of that restudy as part of the price for his help in securing $12 million in federal money to pay interest Metro owes on its bonds July 1.

Is the restudy a quid pro quo for DOT help on the interest? Adams was asked.

"Oh yes," he said. " . . . We have been operating in good faith. I was a little surprised at the [hostile] reaction to our proposals."

Washington area politicians and organizations have written to Adams telling him they oppose a restudy of the Wheaton line, which would run from Silver Spring through Forest Glen and Wheaton and terminate in Glenmont.

Those same officials - representatives of the Metropolitan Washington Council of Governments (COG), the Metro Transit Authority, the Transportation Planning Board of COG and a regional task force studying subway lines and called the Joint Policy Steering Committee - are scheduled to meet with Adams today to discuss the Metro problem.

Adams started the discussion with a letter to those groups May 18. In that letter, he outlined an offer of federal assistance on the long-term Metro bond interest commitments and "requested" a restudy of the Wheaton line. Other proposed lines in the projected 100-mile subway system are being reviewed to determine if there would be adequate ridership to support cost-intensive subway construction.

A flurry of letters from local officials to Adams followed. All of them supported retaining the Wheaton line without further study. Montgomery County Executive James P. Gleason threatened to pull out of the regional subway system if a restudy is ordered.

Gleason has said he is convinced that there is a "preconception" among Transportation Department staff members to cut the Wheaton line. Adams reiterated in his letter yesterday that his department has "no preconception."

However, the letter said, "We believe there are large cost-saving protentials for both federal and local funds through a different alignment or terminus of the (Wheaton) route. For this reason, I must insist that these potentials thoroughly be examined in the context of the alternatives analysis (restudy) already under way."

Gleason, when informed of Adams' letter by a reporter, said, "The only thing I can say is that I am reviewing our legal remedies . . . He's changing the rules." Gleason noted that the Ford administration had decided that the Wheaton line need not be restudied.

The problem with restudy, Gleason said, is "one of time. That line has been studied and restudied . . . The fundamental problem is that the President is not supporting mass tranist. He can still move around on his peanut farm.

"I am vey serious about pulling out of the system and getting our money back."

Transportation Department officials contend, however, that the studies already accomplished have been nothing but reaffirmations of an original decision by Montgomery County to build the Wheaton line.

The line, about four miles long would be in deep rock and would cost about $275 million to $300 million to build.

It would seve one of the Washington area's most densely populated corridors - upper 16th Street and georgia Avenue. High density is regarded as a must to justify subway construction.

If the $12 million bond interest payment is not made by July 1, Metro technically would be in default. However, the bonds are federally guaranteed, so the government would also be holding the bag.

Adams has also said he wants to help find long-term solutions to Metro's Construction and operating cost.