TAS vs GS

[grandfred29 180]

Good day

 

I am flying from Rome to London, minutes ago, a traffic was flying parallel to me, more faster although. We were a fl340, on FR24 i checked her ground speed was 440 knts, that correspond to my TAS speed, at the same Time, my GS was 310 knots, a32N msfs 2020.

It is normal ?

Thanks

[JRBarrett 3,121]

Ground speed is affected by wind. If you have a 120 direct knot tailwind, your ground speed will be TAS + 120. If you had a 120 knot direct headwind, your groundspeed would be TAS - 120.

The upper level winds generally blow west to east and can be extremely strong in winter. One of our company aircraft did a flight to California on Monday from New York. Heading west, their ground speed was averaging 350 knots, and the flight took over 6.5 hours. On Tuesday they returned. The eastbound flight had a ground speed averaging over 540 knots. At one point, it exceeded 600 knots! The return trip took just 3 hours and 16 minutes.

The ground speed you get in MSFS will depend on whether you are using Live Weather or not, and how accurate the wind speed prediction is for your location and altitude. I assume the other flight you were tracking was a real aircraft since you mentioned FR24?

[grandfred29 180]

I know that, it's not the problem.

Yes flightradar24. Same direction same level, FR24 use ground speed but as i said this speed correspond to my TAS not my GS. So something isn't right here.

 

Edited March 3, 2022 by grandfred29

[kiek 1,229]

3 hours ago, grandfred29 said:

 So something isn't right here.

You should look into MSFS for the problem because FR24 and PSXT are real live data, they are to be trusted.

[JRBarrett 3,121]

5 hours ago, grandfred29 said:

I know that, it's not the problem.

Yes flightradar24. Same direction same level, FR24 use ground speed but as i said this speed correspond to my TAS not my GS. So something isn't right here.

 

In order to have the same groundspeed while flying parallel to a real aircraft displayed in FR24, you would have to have exactly the same simulated wind in MSFS as the real wind affecting the real aircraft. It would have to be the same direction and the same velocity That depends on how accurate Live Weather is at the particular location in the sim where you are flying.

If your ground speed was 310 knots and your true airspeed was 440 knots, it means that (in MSFS) you had a 130 knot headwind.

The A320N in MSFS has a wind display - it should show the direction and velocity of the wind affecting your aircraft.