How the SR-71 Blackbird Needed Two Buick V8 Engines to Start Its Jets

The SR-71 Blackbird, the fastest jet-powered aircraft ever flown, couldn't start its own engines. Instead, it relied on a ground cart powered by two 401 cubic-inch Buick V8 engines, known as the AG-330 Start Cart. The cart's V8s spun the Blackbird's Pratt & Whitney J58 turbojets up to the required RPM for ignition, using a vertical drive shaft to connect to the engine's starter pad. This unusual starting method was necessary because the J58 engines were designed for extreme high-speed, high-altitude performance, not for self-starting. The Buick engines, originally from the 1960s, were chosen for their reliability and power. The AG-330 was later replaced by a quieter, more efficient pneumatic system, but the original carts remain a legendary part of SR-71 lore. The SR-71's operational history, from reconnaissance missions over the Soviet Union to setting speed records, was made possible by this ground support equipment. The story highlights the incredible engineering behind the Blackbird and the often-overlooked ground crews who kept it flying.