Pepsi paid millions to paint a Concorde in its iconic blue livery. But the passengers who paid first class fares to fly the iconic jet got a much slower and shortened ride as the blue paint heated the jet so much it was allowed to fly at Mach 2 speed for a mere 10 minutes. //
In the spring of 1996, one of the most ambitious and unusual marketing projects in aviation history took to the skies. Air France’s Concorde F-BTSD, known as “Sierra Delta,” was temporarily repainted in a vivid cobalt-blue Pepsi livery as part of Pepsi’s global “Project Blue” rebrand. The aircraft, instantly recognizable for its sleek, needle-like shape, now carried the bold Pepsi logo across its fuselage and tail. For several weeks, it toured major cities in Europe and the Middle East, hosting media and VIP flights. It was a spectacular sight and a daring collaboration between engineering prestige and consumer branding. Yet behind the beauty of the blue jet lay a technical limitation that few outside the project knew: this Concorde could not safely reach its full Mach 2 cruising speed. //
Dark colors absorb far more heat than they reflect, and when tested on Concorde’s aluminum skin, this quickly became a problem. The engineers at Air France Industries and Aérospatiale calculated that sustained flight at Mach 2 with the blue paint would raise surface temperatures dangerously close to the structural tolerance of the fuselage, as pointed out by Avions Legendaires. https://www.avionslegendaires.net/2025/10/actu/quand-le-concorde-se-muait-en-avion-sandwich-pour-pepsi/ //
To further protect the aircraft, a clever compromise was made. Only the fuselage received the dark blue finish, while the wings remained white. This was not a matter of design balance but thermal management, as the wings housed fuel tanks that acted as heat sinks during high-speed flight. Even with this precaution, engineers observed that the blue-painted panels heated up faster and cooled down more slowly than expected. The short-lived experiment confirmed once again that Concorde’s reflective white finish was essential for safe operation at its top speed. ///
So why did the SR-71 work better with black paint, but the Concorde had to have white paint to avoid overheating? Is it the difference between the titanium skin vs the aluminum skin and at the higher temperature of the SR-71, black paint is more effective at radiating heat and the white paint of the Concorde is more effective at reflecting heat at the lower temps?
