Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number D 505 9PC21 23 24 27 found under Housing Mechanical by Electric Boat Corporation. The National Stock Number assigned to this part is 3040014512703, and the Federal Supply Class is 3040 Miscellaneous Power Transmission Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like D 505 9PC21 23 24 27.