Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 7 311A21272 found under Duct Assembly Air C by Boeing Company The. The National Stock Number assigned to this part is 1660012413469, and the Federal Supply Class is 1660 Aircraft Air Conditioning Heating And Pressurizing Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 7 311A21272.