Tag: MPH

• On Wednesday, at least two transatlantic flights reached top ground speeds above 800 mph.

• They were still technically subsonic because they were propelled by a faster-than-usual jet stream.

• Recent cold weather strengthened the jet stream, and the climate crisis is set to exacerbate this.

Some transatlantic flights traveled faster than the speed of sound relative to the ground this week.

It isn’t the return of Concorde — instead, regular wide-body jets were flying through an accelerated jet stream.

According to data from Flightradar24, Qatar Airways Flight 704 reached a top ground speed of 833 mph as it crossed the Atlantic on Wednesday.

The Boeing 777 flying from New York to Doha landed about 50 minutes ahead of schedule.

Also briefly traveling above the speed of sound was British Airways Flight 274, which hit a top ground speed of 814 mph during a trip to London from Las Vegas, per Flightradar24 data.

The Airbus A350 landed 45 minutes ahead of schedule.

While both flights’ top speeds were above Mach 1.2 when taking their cruising altitudes into account, there would not have been a sonic boom.

The planes were traveling at their usual cruising speeds — typically about 600 mph — but were propelled by the North Atlantic jet stream flowing much faster than usual.

So, while the planes traveled above the speed of sound relative to the ground, they were still subsonic relative to the air around them.

The jet stream has been made more powerful than usual by the recent cold spell in the US.

This was also set to bring high winds to the UK and Ireland as part of Storm Éowyn. Red warnings — meaning there is a danger to life — were in place for all of Ireland and parts of Scotland for Friday, with wind gusts expected to be as high as 100 mph.

While Wednesday’s flights were rare in going over 800 mph, it isn’t clear that any records were broken.

The fastest subsonic transatlantic commercial flight recorded by Guinness World Records took place in 2020, when a British Airways Boeing 747 flew from New York to London in 4 hours and 56 minutes.

Relative to the ground below, it flew through the jet stream at 825 mph.

But its top speeds were sustained for longer than Wednesday’s flights, given that the flight was over two hours quicker than usual.

It may not be long before records are broken again, though.

Most flights between the US and Europe travel through the North Atlantic jet stream, and its tailwinds are the reason it’s faster to fly to Europe from the US rather than vice versa.

The climate crisis means that the jet streams are becoming stronger and, therefore, faster.

It is causing an increasing difference in energy between two layers of the atmosphere, which imparts more energy into the jet streams.

This also enlarges Rossby waves — meanders in the jet stream — which creates more friction in the air and increases the risk of turbulence on the edges of the jet stream.

If you want to see a true supersonic commercial flight, you’ll have to wait a few more years.

Boom Supersonic, a US startup, is developing an airliner planned to travel at Mach 1.7, with plans to enter service before the end of the decade.

Correction: January 23, 2025 — An earlier version of this story overstated how many flights travel through the North Atlantic jet stream. Most flights, specifically between Europe and the US, do so, but other transatlantic flights often do not.

Read the original article on Business Insider