TIE/d's are pilotless TIE Fighters run by onboard droids, designed by Arndall Lott following the Battle of Endor. Lott used the Katana fleet as an inspiration, seeing that the automated systems could work if implemented correctly. Lott originally automated the AT-AT, but his early work suffered from lack of computer power. The TIE/D has received the best automation the Empire could afford, and could be used as independent fighters or computer-slaved squadrons. However, the initial TIE/Ds were not very powerful, and were only effective in large numbers. The TIE/D measured 6.1 meters, and resemble the center section of a TIE Fighter with squared-off TIE Interceptor-like wings which were flat and tilted. The TIE/D was armed with a pair of laser cannons, and lacked a hyperdrive. A Cybot Galactica Ace-6 combat droid brain is the heart of the ship, but was shown to be greatly inferior to human pilots. The TIE/D, although produced in large volumes to overwhelm New Republic starfighters, was primarily produced by the nuclear furnaces and factories of World Devastators. When these were destroyed over Calamari, the primary sources of the TIE/Ds were eliminated.