McDonnell Douglas, Lockheed and Boeing were three other manufacturers who attempted to design SST airliners for the US market during the 1960s, but without success.
McDonnell Douglas, Lockheed ແລະ Boeing ແມ່ນອີກສາມຜູ້ຜະລິດທີ່ພະຍາຍາມອອກແບບເຮືອບິນ SST ສໍາ ລັບຕະຫລາດສະຫະລັດໃນຊ່ວງປີ 1960, ແຕ່ບໍ່ມີຜົນ ສໍາ ເລັດ.