It was only last month that I wrote about a Norwegian Airlines 787-9 Dreamliner setting a transatlantic speed record from New York to London for a subsonic jet. It took less than a month to break the record.
Last Thursday, February 8th, Norwegian broke its own record, flying a Boeing 787-9 Dreamliner from New York JFK to London Gatwick in 5hrs, 9min. That’s four minutes faster than the last month’s record.
Thanks to a very strong jetstream, the aircraft was able to reach speeds of 799mph.
Led by Captain Martin Wood, the flight arrived into Gatwick almost an hour ahead of schedule.
Did the 787-9 Break the Sound Barrier?
The speed of sound varies by altitude, but is about 768 miles per hour at 30,000 feet. Does that mean the Norwegian flight broke the sound barrier?
No. While the plane traveled 799mph in terms of ground speed, airspeed is actually slower. The flight likely approached Mach 0.9, but did no (and could not) break the sound barrier. Even if had, there would have been no one but fish to hear it.
If a tree falls in the forest does it make a sound?
CONCLUSION
There’s always a flip-side to short flights: no sleep. If I paid big bucks for a flat bed seat only to have dinner served, sleep an hour, than being woken up for breakfast…I’d be ticked! 😉
Those uniforms are hideous.
The 787 isn’t capable of supersonic flight and that’s based on airspeed not groundspeed anyway. So the answer to the supersonic question is an unequivocal no.
“If I paid big bucks for a flat bed seat only to have dinner served, sleep an hour, than being woken up for breakfast…I’d be ticked!”
Lucky for you, DY doesn’t have flat beds. 🙂
I will add if I were BA I would be looking for a chance to have one of my 747s break this record as it’s clearly a faster airplane than the 787. It’s likely going to take some ATC coordination on arrival though to avoid the usual turns in holding inbound to LHR.
“Unlikely. While the plane traveled 799mph in terms of ground speed, airspeed is actually slower.”
Airspeed is slower but that’s not a clear way to think about it. You should change this from “Unlikely” to “absolutely not”. The plane cutting through the air at 799mph (ground speed) with a strong tailwind will make noise that travels even faster in front of the nose. This is because the air in front of the nose was already moving (at wind velocity) when it collided with the plane. That collision creates sound waves which then travel through the fast moving wind ahead of the plane. As the plane accelerated to this ground speed sound, waves did not compress together in front of the fuselage, causing a sonic boom. Instead, they dissipated just as they would have in a 0.0 mph wind situation. As far as an observer in the plane is concerned, travel is around mach 0.86. To break the sound barrier, the plane would have to have enough power to do it by itself. The wind essentially offers no help in either direction.
Just to be clear, I changed “unlikely” to “no”.
Yeah, the plane would probably would break apart if it went supersonic. Ground speed and airspeed are two different things.
It reminds me of my younger days with model rockets and one little guy would go supersonic shortly after leaving the launch rail. Too small in a big dry lake bed to hear the boom.
Source?
Source of the story? Link is in opening paragraph.
Actually, this is a very fun story to me. Flight is still a thrill and a source of fascination even after 7M flight miles and counting. Smile when I see how it gooses the competitive instincts and pride.
Maybe the airline executives will understand it is not all about the profit and loss sheets.
The recent Norwegian flight set the record for the fastest subsonic flight from New York to London (five hours and sixteen minutes). In Feb 1996, a British Airways Concorde flew from New York to London in two hours, fifty two minutes and fifty nine seconds.
In Sept 1974, a US Air Force SR-71 Blackbird flew from New York to London in one hour, fifty four minutes and fifty-six seconds and holds the record for the fastest transatlantic flight from New York to London.