An unusually fast jet stream wind has provided the medium for a Norwegian passenger plane to hit an astonishing 779 mph in a recent Trans-Atlantic flight. Norwegian flight DY7014, a Boeing 787, took off in New York City and landed 5 hours and 13 minutes later at a London airport, three minutes faster than the previous record and half an hour faster than usual. Passenger airplanes typically hit cruise speeds of ~550 mph. What’s interesting about this event is that the airplane was not a supersonic jet, but managed to hit supersonic speeds without actually crossing the sound barrier of ~660 mph for typical passenger plane cruising altitudes.

theweathernetwork.com

This is because the 779 mph was measured with respect to the ground, not the air around the plane. Due to the jet stream already moving so fast, the air moving over the airplane’s wing was only moving at an effective speed of about 555 mph, which is much less than the speed of sound. Another way to think about this is to imagine the jet stream as a moving object that contains the airplane rather than a “helping wind”. The airplane flew 555 mph within that object, but because that object was also moving in the same direction the plane got to its destination even faster.

This is an extremely useful concept in the aviation industry, and it has a great impact on flight times so that people can get to their destinations faster. This is a great example that shows how technology and science merge by taking advantage of naturally occurring events and using them to increase a technology’s capability. If the information regarding the jet streams was never discovered by scientists, it could not have been transferred to the aviation industry to benefit pilots and engineers.

https://www.wired.com/story/norwegian-air-transatlantic-speed-record/