Naval Training Device Center, Port Washington, N.Y., technical report NAVTRADEVCEN (series). 330-1-2. Design for maintainability, supp. 2, Survey information: (A) Description of training device technician, B, Engineers' estimates of circuits and system maintainability; prepared by J. M. McKendry, C. Grant, J. F. Corco, HRB-Singer, Inc., State College, Pa.