Richard W. Bohlen appointed senior vice president-operations for Rockwell International Corp., El Segundo, Calif., effective Jan. 1, 1988; he will succeed Donald J. Yockey, who continues as senior vice president. Stephen D. Spence, currently executive vice president-business operations for Rockwell’s Telecommunications Div. in Dallas, will succeed Bohlen at the Measurement & Flow Control Div. in Pittsburgh. Robert H. Gulcher has been named vice president and program manager of the National Aerospace Plane (NASP) program at Rockwell International’s North American Aircraft Operations (NAAO).