Russian-English program only one of its kind outside Soviet Union

Mayande Gowon wants to go to the Soviet Union someday. His father is a fencer , and Mayande has heard that fencing is popular there. When the day comes for this 13-year-old New Yorker to step off a plane in Moscow or Minsk, he shouldn't have much trouble understanding the natives. He's learning Russian.

Mayande is one of about 50 boys and girls who go to St. Sergius High School in Manhattan, the only bilingual Russian-English high school outside the Soviet Union. Not only are students required to study Russian, they take the usual load of college preparatory courses (in English), and also must study Russian literature, history, music, art, and religion - in Russian.

Archimandrite Anthony Grabbe, a Russian Orthodox priest who is founder and principal, started the school in 1959 in an effort to preserve Russian culture among Russian-Americans. In its infancy, the school's students were all from New York's Russian community. Now roughly half are non-Russian, coming from many cultures: black, Greek, Vietnamese, Jewish, Muslim, and others.

Fr. Grabbe's idea is particularly timely now. Over the past couple of years various studies have lamented the shortage of Soviet experts in the United States. The most recent, published by the American Association for the Advancement of Slavic Studies, reports that enrollments in Russian-language courses have plummeted: Over the past decade the decline among college students is more than 40 percent; among high school students, it is 70 percent. No other major language has suffered a more serious decline. Also, there are now more teachers of English in the Soviet Union than there are students of Russian in the US, the study says.

In a well-publicized gesture two years ago, Averell Harriman, former US ambassador to the Soviet Union, gave $11.5 million to Columbia University's Institute for Advanced Study of the Soviet Union to bolster its program. And on the last day of its 1983 session, Congress approved $50 million to encourage study of the Soviet Union.

Fr. Grabbe is heartened by increased public awareness of the value of studying Russian. He proudly points out that his students get a head start by beginning their study before college.

''When the students reach college age, they will not be at the mama-papa level in Russian,'' he says. ''These students can study Soviet politics and culture (in Russian) at the university level.''

Already, many graduates work as interpreters, in diplomatic work, and in other international milieus. Virtually 100 percent of St. Sergius graduates head for college, and many continue their study of things Russian.

Fr. Grabbe has seized on his school's timeliness to appeal for funds. Since the school is relatively young - with a small pool of alumni, no grants from foundations, and not much name recognition - money problems are constant. Fr. Grabbe has ambitions of moving the school to larger quarters so he can admit more students. But this, of course, requires large amounts of capital.

Teachers admit their salaries are low, but they quickly point out that the satisfaction of working to promote Russian culture provides compensation one can't put a dollar value on.

It is obvious why Russian children would want to go to St. Sergius. For those who arrived in the US at an early age, it would be all too easy to forget their mother tongue. For those born in the US, studying at St. Sergius is an opportunity to learn the language of their heritage.

Fifteen-year-old Alex Krutyansky immigrated with his family from the Ukraine six years ago. He quickly asserts his Americanness, insisting he be called Alex and not Aleksandr, which he says is ''too Russian.'' Yet he understands the value of keeping up his Russian. Many young immigrants don't, wanting instead to be just like their classmates.

Non-Russians turn to St. Sergius for less obvious reasons. Mayande Gowon didn't enroll to learn Russian. He was a particularly bright student who was bored in public school, and St. Sergius's reputation as an all-around good school - and its 7-to-1 student-teacher ratio - attracted him. ''It has good teaching methods,'' he says. ''Learning Russian is a bonus.''

The school makes a special effort to accommodate the inevitably wide range of language abilities. (Students can enter the school at any grade level.) It offers courses in Russian and English as a second language for those who arrive with limited or no knowledge of one or the other. Eleven-year-old Claudio Llobet came to the US three years ago from Venezuela, knowing neither language. He gets tutoring in both.

''We make a special effort to see that these students don't fall through the cracks,'' said Lonny Lockwood, a young teacher, as he typed out evaluations of his fifth- and sixth-graders to give to their parents at open house.