Perpetual Federal Savings & Loan Association yesterday appointed three top officers and announced the election of a new director for the area's largest thrift institution.

Individuals involved are:

H. Grafton Harper, the new executive vice president and secretary, who joined the S&L in 1932 and has been serving as senior vice president for operations.

Ross Towne, who moved to Perpetual last January after serving as treasurer of First Virginia Mortgage and Real Estate Investment Trust, as vice president and comptroller;

Wade Hotsenpiller, an accountant employed by Arthur Anderson & Co for 12 years before moving to the S&L in mid-1976 to establish an internal audit department, replaces Harper as senior vice president for operations;

Robert B. Washington Jr., a lawyer in the firm of Danzansky. Dickey, Tydings Quint and Gordon, and former chief counsel for the House and Senate District Committees as a director.

Perpetual president Thomas J. Owen, who announced yesterday's promotions and the election of Washington, told stockholders at the annual meeting that total assets rose $75 million in the year ended Oct. $1 to $949 million.

The institution's mortgage loan portfolio increased $77 million in the past year to $840 million and interest paid to depositors totaled more than $40 million for the year, Owen, reported.

Perpetual now has 10 officers is constructing its 11th at the corner of 18th Street and Columbia Road NW, following approval last August from the Federal Home Loan Bank Board. The new branch was delayed for more than a year because of opposition by some citizen groups who asked for certain guarantees about Perpetual lending policies.