Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 99-3580 found under Hook Door Uplock by Hamilton Sundstrand Corporation. The National Stock Number assigned to this part is 1560008654305, and the Federal Supply Class is 1560 Airframe Structural Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 99-3580.