Watching a cam a DFW last night, I saw the British Airways flight 192 on a taxiway using a Boeing 777 rather than the B-747 they usually use. This got me to thinking that with the bigger twin-engine plane and the overhead jet stream still running at 130-150 Miles Per Hour, I logged on to see what the flight had filed as a flight plan for speed and altitude. Every thing checked out as a normal flight---except for the factor of the overhead jet stream's tail wind.
Just as I had expected, the flight was into the tail wind almost before it had reached half of it's flight altitude. Quickly, the flight had reached it's planned speed of 555 mph and the speed just kept climbing. When it hit 700 MPH, it was pretty close to Mach .9 plus.. Of course, the speed of sound has no set number because of temperature, pressure and basic weather conditions like humidity and dew point---kind of like the basic when we check our blood pressure. Never-the-less, the excitement began to build as the plane hit its cruising altitude of 37,000 and the speed kept inching up beyond 700 to 710;715;720. Then, the altitude changed to 36,500. Finally, the speed slowly hit 721.Then 722,then 723,724 and 725 balanced it off. Ironically, the ATC(air traffic control) nickname for BAC192 is
'speedbird'.
Here is a flight headed for London from Dallas and before it is out of Texas into Arkansas, the flight is booking at 725 MPH (living up to it's name of
speedbird, for sure.). That caused me to look at the estimated arrival time. It had already picked up 23 minutes early status. Before the flight made it into Illinois it had settled down to just under 700 mph but continued to book toward Maine, staying inside USA air space until it left Maine's borders.
I went to bed thinking that the jet stream was more close to 155 mph at the altitude and that the flight would most likely land in London early rather than late. I have never seen a commercial flight hit 725 mph, but in the 50s I can remember that boom caused my breaking the sound barrier. There were thunderstorms under the flight as it moved across Arkansas, into Missouri and across southern Illinois, Indiana and into Cleveland Center Airspace. It might have hit the sound barrier and the thunderstorms would have been a pretty good cover. The flight had made that 887 miles in a little over an hour from Dallas departure.
While drinking my coffee this morning, I checked to see just how early it did land in London. 8 hours, 43 minutes with 10 minutes early. The graphs did show the drop in altitue and an increase in the air speed to match that 725 mph speed. Who said that a jet stream tail wind isn't that much of a factor for travel? It was fun to just watch that flight slicing through the air at 725 mph. Sheer excitement.
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Winds at the surface were 40 mph today with higher gust. They blew in dust from west Texas and DFW had a ground stop for a bit. |