The pilot of a small plane in a deadly crash near New Orleans’ Lakefront Airport radioed the control tower shortly after takeoff about unspecified problems and sought clearance to return, federal investigators said Saturday. The pilot and an award-winning television journalist aboard were both killed in the crash Friday afternoon. The National Transportation Safety Board said in a statement that the pilot contacted the tower just before the Aerotek Pitts S-2B went down in a field not far from the airport. “Witnesses reported observing the airplane appeared to have engine problems shortly after take-off,” the NTSB statement said. “According to witnesses the airplane then pitched down and struck the ground.”