Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number PC74991 1 found under Microcircuit Linear by Rockwell Collins Inc. The National Stock Number assigned to this part is 5962012906670, and the Federal Supply Class is 5962 Microcircuits Electronic. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like PC74991 1.