An SR-71 crosses the Atlantic in under two hours flat
On September 1, 1974, an SR-71 crossed the Atlantic faster than any aircraft before it. On September 1, 1974, Maj. James Sullivan and reconnaissance systems officer Maj. Noel Widdifield flew an SR-71A Blackbird from New York to London in 1 hour, 54 minutes, and 56.4 seconds, covering 3,461.53 miles at an average speed of roughly 1,807 mph. The jet refueled in midair to make the crossing. Commercial airliners of the day took seven hours or more; No aircraft has beaten that time since.
A U.S. Air Force crew, in a Lockheed-built jet designed and manufactured in Burbank, California, turned a secret Cold War reconnaissance program into a public demonstration of what the aircraft could do. The same titanium airframe and Mach 3 speed built to outrun Soviet defenses now set a record over the Atlantic that the United States still holds decades later.
QWhy did engineers give the Blackbird a name that made no aerodynamic sense — chines that looked purely decorative?
The chines running along the SR-71's nose were not part of the original A-3 concept at all. CIA-affiliated researcher Frank Rodgers found that a sphere's cross-section scattered radar poorly, and Lockheed stretched that idea into flattened fuselage edges to shrink the plane's radar signature. Wind-tunnel work then revealed a bonus nobody designed for: the chines threw off vortices that generated extra lift, letting engineers reduce the wings' angle of incidence, cut drag, and even raise the aircraft's fuel-carrying weight. The same vortices made the plane resist stalling at landing speed. A feature meant only to hide the jet from radar ended up reshaping how it flew, letting designers scrap the canard foreplanes they had originally planned to add.
QHow much titanium got thrown out before Lockheed could even start building the Blackbird's skin?
At one point 80 percent of the titanium delivered to Skunk Works was rejected for metallurgical contamination. Lockheed also learned the hard way that ordinary tap water would corrode welded titanium because of its chlorine content, so crews had to wash parts with distilled water, and cadmium-plated tools were banned outright because they caused the same corrosion. To keep costs down, engineers used a more workable titanium alloy that softened at lower temperatures, which meant inventing new fabrication methods from scratch. Fuselage panels were built to fit only loosely on the ground, since the airframe would expand several inches once heated in flight. Those improvised techniques later spread into manufacturing for other aircraft entirely.
QWhat happened inside the cockpit when an engine inlet suddenly lost its shock wave in flight?
Air Force crews called it an 'unstart.' If the terminal shock wave inside an engine inlet snapped forward past the cowl, the afterburner would often blow out and the sudden mismatched thrust between the two engines could yaw the jet violently sideways. The whiplash sometimes slammed pilots' helmets into the canopy and triggered loud banging as the opposite engine suffered a 'sympathetic stall.' Early on, crews had to manually unstart both inlets and restart them together to regain control. NASA's Dryden center eventually traced part of the problem to nose-chine vortices disrupting airflow into the engines, and by 1980 a new digital system, DAFICS, replaced the analog controls and largely eliminated the violent unstarts.
