The MTA has reassigned the A train crew to desk duty as it investigates the misadventure, the spokesman said. Before it pins all blame on the train operator, the MTA has to answer these questions: Are the crews' radios inferior to an earlier model, as some workers have claimed? Was that part of the problem here? And why, despite all the advances in technology, are motormen and conductors claiming they still encounter "dead zones" underground where all radio communications are lost?