SR-71 Facts: 29 Details That Might Surprise You
TurboJet Engine
No engine can absorb supersonic air, so the airflow must be adjusted. The ‘spike’ seen above protrudes outward at subsonic speeds like you see in the image above. Although it definitely adds to how cool the SR-71 looks on the ground, it has a much more important role in flight. However, it moves aft once the SR-71 reaches about Mach 1.6, doubling airflow and compressing air in the back of the spike, allowing the SR-71 to reach its famously high rate of speed.