Several top Chinese military officers led by former defense minister Lin Biao were accused today of planning a military offensive, including the use of flame throwers and 40mm bazookas, to assassinate Mao Tse-tung while he was riding in a train from Shanghai to Peking in 1971.

Once the scheme was discovered, according to charges prepared for the forthcoming trial of the leaders of the tumultuous Cultural Revolution, Lin planned to move his confederates to an insurgent headquarters in Guangzhou and launch a nationwide attack with Soviet help.

Finally deciding to scrap the plan, Lin is said to have fled with his wife and son in a Chinese Air Force Trident jet apparently headed for the Soviet Union. Two hours later on Sept. 13, the aircraft reportedly ran out of fuel and crashed, killing all passengers.

Five Chinese generals who allegedly schemed with Lin are awaiting trial on charges of trying to assassinate Mao and stage an armed coup. Mao's widow and her so-called Gang of Four associates also will be tried for allegedly persecuting state and party leaders during the Cultural Revolution.

Most of the charges leveled today against Lin and the other generals were officially revealed after Lin's death. Experts on China long have questioned their accuracy, finding it hard to believe that a skilled military tactician such as Lin could have attemped such a naive assassination and getaway scheme.