new hope in the search for the missing titanic sub, banging noises detected by sonar. plus hunter biden strikes a deal on tax charges and a gun charge but a judge will ultimately get the final say. and urgent call for the u.s. to step in as violence escalates in the west bank. welcome to our viewers in the united states and around the world. i m christine romans. good wednesday morning to you. we begin with what could be a major development in the search for the submersible lost at sea. crews using so he that are have heard banging sounds at 30 minute intervals. and the u.s. coast guard also says that canadian plane detected underwater noises. resources now have been diverted to try to find the source of those noises. no luck just yet. more on the search this morning from miguel marquez. reporter: a complex search now more complicated by time, which they are running out of. we know there is about 40 hours of breathable air left. reporter: deep water submersibles a