SR-71 airflow fragility tied to Mach 3 inlet design

Summary: The SR-71’s Mach 3 propulsion depended on coordinated inlet spike, bypass system, and exhaust airflow that also provided much of the compression. Disrupting this calibrated airflow could trigger compressor stalls, making the flight regime both enabling and fragile. The article also recounts an incident in Vietnam when both engines flamed out, turning the aircraft into a heavy descending glider nicknamed “Lead Sled.”