NBC has the forward essential element going into the May sweeps period.

NBC has the forward essential element going into the May sweeps period, unless the Big 3 networks are looking back.

Inspired by the agency of the smash success of last fall's ``Carol Burnett'' and ``I be pleased with Lucy'' specials, Viacom's CBS, General Electric Co.'s NBC and Walt Disney Co.'s ABC are all counting upon past glories to fuel their May ratings.

Perhaps the chiefly sentimental journey is planned at NBC, with a month-long series of specials and programs for the network's 75th anniversary. This includes a live three-hour conclusion May 5 from its Rockefeller Center studios, a move with a jerk Hope special, ``The ...