In January 1984 a rare incident occurred when  the SR-71 Blackbird  drag chute doors opened inadvertently at high Mach, creating problems, as RSO Lt. Col. Curt Osterheld (Ret) explains in Col. Richard H. Graham’s book The Complete Book of the SR-71 Blackbird:

During the 1980s, the U.S. flew regular SR-71 Blackbird aircraft reconnaissance missions in international waters over the Barents Sea and the Baltic Sea, the latter known as “Baltic Express” missions. On June 29, 1987, during one of those missions, a Blackbird launched from RAF Mildenhall, UK, piloted by retired Lt. Cols. Duane Noll and Tom Veltri, experienced a pretty serious inflight emergency.