PERSONNEL: Madam Director

Militant feminists who make a habit of storming the annual meetings of big corporations to demand the election of a woman director usually get nothing but a polite brush-off. But when the demand was raised at RCA's meeting last May, Chairman David Sarnoff, who never underestimates the power of a woman, had a ready answer: RCA's subsidiary, NBC, had already named Mrs. Mildred McAfee Horton, ex-Wellesley president, ex-WAVE Commander, to its board. Moreover, said Sarnoff, she had proved so valuable that RCA would name her to its own board at the first opportunity. Last week, when Director Arthur E. Braun resigned, RCA's board kept Sarnoff's word, elected Mrs. Horton as its first woman member.