For some 1,600 McKinley High School students the new school year will begin as the old one ended--amid the same peeling paint, crumbling floor and ceiling tiles and windows that list precariously in rotting frames.

Several classrooms and some woodworking and science equipment in the 55-year-old building at Second and T streets NE have deteriorated beyond use and leaks in the roof have left a trail of water damage city officials say will take three years and $3.7 milion to repair.

But McKinley, which school officials acknowledge has been in much the same condition for more than 10 years, is "not the worst" example of deterioration among the District's aging public school buildings, according to Andrew Weeks, acting director of the school system's buildings and grounds division.

Worse, according to Weeks, is Randal Highland, a 74-year-old elementary school in Southeast, where the woodwork and walls may never have been repainted. Principal Tony Jones said 30-gallon garbage cans to catch rainwater have become permanent fixtures in many classrooms.

Fifty of the District's 186 schools are now programmed for major roof repairs, though only two or three a year can be completed with available resources, Weeks said. "Another 50 should probably be added to that list," he said.

The average city school is at least 25 years old and the major maintenance problems are leaking roofs, rot from age and substandard construction, Weeks said. These problems are compounded by years of neglect, he added.

School officials said the neglect dates to the late 1960s and early 1970s when the emphasis was on construction of new schools to accommodate a growing population as well as new educational and social priorities. Little money or manpower was provided for preventive maintenance, which was given a lower priority than instruction or federally imposed requirements such as access for the handicapped, Weeks said.

The City Council this year approved a $26 million capital improvement budget for 1984, which now awaits the approval of Congress. A recent survey indicated, however, that it would take $52 million just to do the backlog of repairs necessary throughout the system, Weeks said.

Enez Martin, a parent of five McKinley graduates, recently toured the three-story red brick building that is still nicknamed "Mighty Tech."

"I call that pure hazard," said Martin, pointing to several gaping holes where rain-soaked plaster has rotted away, exposing decaying beams and rusted water pipes.

"The students here deserve better," said Bettye Topps, McKinley's principal.

"What's frustrating is that we kept calling this to their the school board's attention, and they did nothing," said Andrew Corley, a local ANC commissioner and past president of the McKinley PTA. "Now it has all got to cost a lot more.

Work crews and contractors, laboring furiously all summer, have completed projects in three vocational centers, replaced a portion of the roof on Ballou High School in Southeast, and started the roof repair at McKinley, scheduled for completion by January, Boone said.

"The good news is that we got the money in the 1983 budget for McKinley and the men are on the roof now," said Bettie Benjamin, school board representative from Ward 5.

Other priority projects include completion of major renovations at Eastern High School in Northeast and planned modernization of Coolidge in Northwest, said Boone.

"The way it is now it sends a message to the students that we don't really care," said Topps.

"I don't think that kids can learn as well with the walls peeling and the roof leaking," said Superintendent Floretta McKenzie. "We have been desperate to provide a good environment in the schools, but we just haven't had the money."

"We've got 120 men, which roughly translates to one man per day per building" and a maintenance budget of roughly $7 million to keep up facilities that get hard use from 100,000 people," Boone said.

"It's a mammoth job, and we're just trying to do the job with what we have," Weeks said.