The former president of Trustbank Savings F.S.B. of Tysons Corner said last week his resignation after 10 months on the job came out of sheer frustration with the environment in which thrifts across the country must operate.

"Congress has made it very difficult for the industry to survive," said David L. Erickson, an accountant who joined Trustbank in 1983 as chief financial officer and became president in January. "They've handcuffed the thrifts. There's no capital out there. Businessmen have given up on the industry because they don't think it can survive the way it's been structured."

Trustbank, a $1.8 billion thrift that lost $18.7 million in fiscal 1990 and $17.3 million the previous year, hired real estate lawyer William J. Dorn as its first-ever senior executive vice president after Erickson resigned.

Erickson, who says he turned down feelers from four area thrifts after his departure, is joining a privately held accounting firm in the area. He declined to identify the firm.

The thrift also promoted Randolph N. Click from executive vice president for retail banking to chief operating officer.

Trustbank Chairman and chief executive William L. Walde assumed the title of president.

Under its new leadership, Dorn said, Trustbank will continue a "shrinkage" program that has cut 500 of 1,500 jobs in the past three years and reduced total assets by nearly 15 percent last year.

He said he has no target figure for employment levels but hopes to bring assets down below $1.5 billion in the next year.

"We're being balance-sheet driven," Dorn said. Trustbank does not meet current government requirements for cash reserves to protect against bad loans.

It therefore cannot increase its loan portfolio, which contains most of its assets, and must resell loans it holds before giving out new ones.

Dorn, who has been Trustbank's legal counsel since the early 1980s, said he was optimistic about the thrift's future.

"Obviously, if I didn't personally think this institution could be saved and was worthy of being saved, then I wouldn't have done it," he said. "The challenge and the opportunity seems real."

But he added that achieving Trustbank's long-term goal, regaining profitability, would not be easy. "This is a tough, tough era," Dorn said. "What's needed now is not what got us here."

The Trustbank post is Dorn's first full-time foray into banking.

The 52-year-old Tennessee native spent most of the 1970s working for Colgate-Palmolive Co. in New York and opened Stauffer & Dorn, a Tysons Corner law firm, in 1981.

Trustbank, then called Dominion Federal Savings and Loan Association, retained the firm almost immediately.

Dorn continued to represent the thrift when his law firm merged with Baltimore-based Frank, Bernstein, Conaway and Goldman.

This summer, the law firms decided to undo the merger and resume separate practices.

Dorn said he saw the move as a chance for a career change.

"There we were, discussing David's replacement without any names, and I fit {the description} perfectly," Dorn said.

He said he had developed an "intimate" knowledge of the thrift's operations

The turnover extended to the thrift's board of directors as well.

In addition to Erickson, Vice Chairman Zalmon Chelec and Director D. Gay Walde, who is married to the thrift's chairman, resigned from the nine-member board.

Dorn and Click will assume two of the seats, and Dorn said a search committee is looking for an outsider to fill the third opening.

Trustbank stock tripled the week the changes were announced, closing at 25 cents Sept. 28 and 75 cents Oct. 5. It closed at 37 1/2 cents Friday.

Chelec, chairman of Zalco Realty of Silver Spring, would not elaborate on why he left the board. "I've had my 15 years there, it's just time that I move on," he said.

But Walde said she resigned because the board needed new blood.

"I {was happy} to give up my seat for Bill Dorn," she said. "He is full of enthusiasm: He is ready to go to work. It's still going to be a fight in this industry, and we need people who have vigor."

She said Chelec was fully absorbed by his own property management company.

"His people needed him there full-time," she said, "and that's his livelihood. Trustbank is not his livelihood."