Strong high-altitude winds over the Mid-Atlantic sped up sky traffic on Saturday night, getting passengers on at least two commercial planes to their destinations early, after both aircraft hit supersonic speeds topping 800 mph.

Winds at cruising altitude peaked at about 265 mph, according to the Washington, D.C., area National Weather Service office — the second-highest wind speed logged in the region since recordings began in 1948. The highest-ever wind speed recorded in the area at a similar altitude was 267 mph on Dec. 6, 2002.

“For those flying eastbound in this jet, there will be quite a tail wind,” the NWS warned in a tweet.

Sure enough, that tailwind helped cut down the flight time for passengers on a Virgin Atlantic flight from D.C. to London by 45 minutes, according to the tracker FlightAware.

  • TheWeirdestCunt@lemm.ee
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    10 months ago

    A) no it’s not supersonic because that depends on airspeed not ground speed

    B) this is normal for west bound flights

  • roertel@lemmy.world
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    10 months ago

    While this is an incredible travel speed, I wouldn’t consider it “hitting supersonic” speeds based on ground speed. I read the article wondering about the safety of passenger aircraft at 800MPH, but it seems to not apply.

    I’m not a pilot, though.

    • Pretzilla@lemmy.world
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      10 months ago

      Narrator: It’s not.

      Poorly written summary. Supersonic means exceeding the speed of sound (duh) and the indicated airspeed of the plane at cruising altitude would still be around 250kts, about 1/3rd speed of sound.

    • I_Miss_Daniel@lemmy.world
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      10 months ago

      Yeah I was curious about that too.

      The plane can’t really slow down to compensate in guessing as it would lose lift? Or it could extend flaps maybe.

      • orclev@lemmy.world
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        10 months ago

        There’s no reason at all for it to slow down. If you’ve ever been on one of those moving walkways think about it like that, yes by walking on it you’re moving faster than the people around you, but to you you’re not walking any faster than normal even though you’ll arrive at your destination earlier.

        • MightBeAlpharius@lemmy.world
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          10 months ago

          That’s actually a really good analogy. Mind if I throw some numbers on it to flesh things out?

          Let’s set that moving walkway going at 5mph, and we’ll put ourselves on that walkway, on a turned-off rascal scooter. The scooter is stationary on the belt, but it’s still moving at 5mph - that’s your tailwind pushing the air around the plane forward.

          Now, let’s turn that scooter on and throttle it up to 5mph. The scooter is plugging along comfortably at 5mph, but it’s actually moving at 10mph. This is your plane flying with a tailwind, performing normally for its indicated air speed, while having a much higher ground speed.

          Curiously, this does make the phrase “supersonic speeds” somewhat debatable. While they were traveling over the ground faster than sound would, they weren’t moving faster than sound would in the air around them.

  • shalafi@lemmy.world
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    10 months ago

    The supersonic claim reeks of bullshit. Humans had a hell of a time engineering a plane that could withstand that speed, and I’d guess passenger jets would tear apart.

    “Although its ground speed — a measure that combines the plane’s actual speed and the additional push from the wind — was greater than the speed of sound, it was still moving through the surrounding air at its ordinary cruise speed. It just so happened that the surrounding air was moving unusually fast,” the Post reported.

    Oh! Never knew what “ground speed” meant. So no, those planes were not leaving a sonic boom. Not even close to supersonic at typical altitudes.

    (Apologies, don’t know how to format a table on here.)

    
    Sea level	15 °C (59 °F)	761
    
    11,000 m−20,000 m (Cruising altitude of commercial jets, and first supersonic flight )	−57 °C (−70 °F)	660
    
    29,000 m (Flight of X-43A )	−48 °C (−53 °F)	673
    
    
    
    
    • Everythingispenguins@lemmy.world
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      10 months ago

      So you are right they were not going supersonic speeds, not even close. Yes their ground speed exceeded the speed of sound, but ground speed is only meaningful with how fast the plane is going to get to its destination. The plane only cares about air speed.

      So it is all about the frame of reference. For a plane in flight the air is in a different frame of reference than the ground. To be supersonic the plane needs to be moving supersonic speeds in relation to the air not the ground.

      Also just to make life more fun supersonic is not a transition that happens at a set speed. It is actually pressure dependent. At standard pressure and temperature it is 786mph, but it will go up and down with changes to pressure and temperature.

      The true definition of supersonic is when the air the plane is pushing is no longer able to flow around the plane and instead is compressed in front of it. But that definition is hard to put on an air speed indicator so they just use 786mph better known as Mach 1.0.

      Thanks for coming to my TED talk.

      Spelling

    • lennybird@lemmy.world
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      10 months ago

      Ah so that’s how aliens fly supersonic without breaking the sound barrier. Just move the air around the craft in the direction they’re going! Problem solved.

  • mlg@lemmy.world
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    10 months ago

    In case anyone is wondering, there are actually subsonic aircraft that can handle going mach.

    The F-86 Sabre had a max speed of 687 mph at sea level which is about mach 0.9

    But the Sabre could enter a dive from a higher altitude and safely reach past Mach 1 with help from gravity (or another additional source like rockets).

    Comparatively, the MiG-15 had poor control authority reaching mach 0.9 and would subsequently break apart if it reached past mach 0.92.

    Modern airliners obviously aren’t fast enough to reach mach under their own power, but they also can’t handle the pressure if they used something like a dive so they would also break apart like the MiG.