Two hundred and fifty members of the People's Coalition for Peace and Justice packed the MIT Student Center last night to plan a series of demonstrations against the recent bombing step-up in Indochina.

The meeting voted to support today's SDS-sponsored demonstration here against Robert C. Seamans '40, Secretary of the Air Force, who is on campus as a member of the visiting committee to the Physics Department.

The group also laid plans for a mass demonstration in Boston on Friday and for a rally at Hanscom Air Force Base in Lexington on Saturday. The Saturday rally is intended to publicize the current military build-up across the country.

Friday's demonstration will begin at 3 p.m. with feeder marches from Boston-area colleges to Government Center, where a B-52 will be burned in effigy.

It will culminate in a mass rally on the Common at rush hour, pausing along Tremont Street for a protest at the Republican State Committee headquarters, which one speaker charged was "a subsidiary of ITT."

Active-duty airmen will speak at Saturday's rally at Hanscom Field. Seventy-five per cent of the men stationed there have been notified they could be going to Vietnam, a speaker from the Legal Services Project said last night.

The meeting did not formally endorse any other demonstrations. However, speakers announced and solicited support for the following

* a "New American Revolution" celebration in Lexington on Patriots' Day, April 17;

* a mass antiwar rally in New York City on April 22, sponsored by the National Peace Action Coalition;

* a "militant disobedient obstructive" demonstration at Government Center on May 8, also sponsored by the coalition; and

* an SDS-sponsored May Day celebration in Washington, intended "to smash the government.