Ayatollah Ruhollah Khomeini accused "lackeys of the great Satan, criminal America" yesterday of masterminding the assassination of his personal representative in Tabriz and vowed revenge, Tehran radio reported.

Iran's 81-year-old revolutionary patriarch also replaced the commander of Iran's Air Force, and a government spokesman said elections to replace the slain president, Mohammed Ali Rajai, could be held before the end of this month, according to the state-run radio.

Khomeini's vengeance oath was made in a radio message as his personal representative in Tabriz, Ayatollah Assadollah Madani, was buried in the provincial capital of East Azerbaijan Province.

"The people, with an unshakable will, will take revenge for this latest crime of the vicious hypocrites," Khomeini said in the radio message monitored in Beirut. "May God's eternal disgrace and curse befall the lackeys of the great Satan, the criminal America, which thinks that with such conspiracies . . . it can weaken the revolutionary will of the Iranian nation."

Hypocrites is the term Khomeini's fundamentalist Moslem government uses for Mujaheddin-e-Khalq, the underground leftist group that leads the 11-week-old urban guerrilla war of bombings and assassinations aimed at overthrowing Khomeini.

Khomeini removed Col. Javad Fakouri from the Air Force without explanation and replaced him with the vice commander, Col. Mohammed Moinpoor.