Why 4,000 Missiles Still Couldn’t Stop the SR-71
When getting a glimpse of a missile attack, one of the most bizarre engagement strategies of the SR-71 Blackbird was to not turn, descend or retaliate. It was supposed to be a matter of pushing the throttles over to the starting point and let physics take over. The doctrine proved to be valuable during the U-2 era because a corollary of this was that survival was no longer assured by simply operating at higher altitudes. That challenge was successfully repelled and the Blackbirds kept to Mach 3.2 and around 85,000 ft where the air-defence radar crews were not very successful at tracking them. In all these years, the SR-71 did not have to be manned by anyone who could shoot it down. No one had ever tried to shoot down the SR-71 over the years it was flying.
Numbers don’t have any significance outside of considering the plane’s propulsion system. The Blackbird’s two Pratt & Whitney J58s were not the normal jet engines that were just being used more than usual. All inlet-engine-nozzle system had to become the machine at a high speed. As per a technical history of the power plant provided, 54% of the air is used to provide thrust above Mach-3, and the pressure plant provides considerably less thrust, as many people believe. It was that an airplane’s engines wouldn’t have been the only thing that gave it the lift, or the shockwaves, or the ram compression, optimized propulsion system for the altitude range where most dangers were already on steroid steroids—all of these things would have helped.
A surface-to-air missile was heading towards the jet with a certain concern. The first task the missile flew in doing for the Blackbird was to first ascend to the same level as the aircraft and burn off some valuable fuel before any potential intercept could begin. All the time, the SR-71 continued to speed up. There were no angles, altitudes or speeds deviations allowed without disrupting order as the defender’s radar blip in the nose was the closest he could get and the length of his time seemed to drain out of him as he flew by. The result was not to make the missile crew bulletproof, but instead a means to make engagement envelope against the missile crew.
Such a slow speed was survivable because of the air frame. For example, the SR-71 is made of about 85% titanium because the high temperatures produced by the SR-71’s sustained cruise flight at Mach 3 eliminated the possibility of using aluminum alloys. At certain sites, the skin temperature reached up to 1000°F and the panels were also somewhat detached from the ground to allow expansion of the panels in the air to ensure correct alignment. For this reason, the Blackbird was able to weep fuel when it was standing idle, but it was get-tighter, get-hotter and begin to gain increasing structural integrity when it was accelerated into its intended regime.
One of the more obvious was a post-strike Senate Armed Services Committee reconnaissance over Libya in 1986 that targeted the aircraft used by Muammar Mohammed Gaddafi.One of the most notable examples was a post-strike Senate Armed Services Committee reconnaissance flight in 1986 to Libya that targeted Muammar Mohammed Gaddafi’s aircraft. Later, pilot Brian Shul wrote, “The plane was flying a mile every 1.6 seconds, well above our Mach 3.2 limit. It was the fastest we would ever fly.” His reconnaissance man in his systems, had been warning him of any missile launches, and they had proceeded along their course sufficiently far to have made the turn safely and returned to the Mediterranean. The plane was lucky to escape hurtling by itself on the outbound line of the tanker and ended up missing the set course.
The Blackbird’s legacy is frequently remembered for setting speed records like record 1976 sustained speed of 2,193.16 mph, but it was here that he was more important making operational records. If survivability was going to be done, it illustrated that it would be done by engineering, and not via weapons. All of the factors which enabled it: sensors; height; low observability; propulsion; thermal system design: they were all doing the same thing: getting in; learning bits and pieces; getting out; doing calculations; before the defence network could do its calculations. Therefore there are no parallels to the SR-71. It was not only fast for its time! The construction was to make the fastest of the defenders the defense system.
