Hermann Frederick Eilts, 84, the American ambassador to Saudi Arabia and Egypt who helped negotiate the Camp David peace accords, died Oct 21 of complications of heart disease at his home in Wellesley, Mass. Mr. Eilts, one of the State Department's first Middle East specialists when he entered the Foreign Service in 1947, was a diplomat for 32 years. Described in a 1979 Washington Post profile as a man with unflappable self-control, he helped keep peace during some of the major world crises of the 1970s and '80s. He first served in Saudi Arabia when the kingdom had just learned to pump oil for the international market and later was U.S. ambassador there during the 1967 Arab-Israeli Six-Day War. He aided former Secretary of State Henry Kissinger during the 1974-75 period of shuttle diplomacy and became close to Egyptian President Anwar Sadat during the tense negotiations with Israel in 1977 and 1978.