 Hua was called to Beijing to direct Zhou Enlai's State Council staff office in 1971, but only stayed for a few months before returning to his previous post in Hunan.Later that year, he was appointed as the most junior of the seven-member committee investigating the Lin Biao Affair, a sign of the strong trust Mao had in him.Hua was re-elected to the 10th Central Committee in 1973 and elevated to membership in the Politburo; in the same year, he was put in charge by Zhou Enlai of agricultural development.