Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 27 21139 029 found under Hook Battery by Swearingen Aviation Corp. The National Stock Number assigned to this part is 1680011962959, and the Federal Supply Class is 1680 Miscellaneous Aircraft Accessories And Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 27 21139 029.