What's the furthest away you've seen a plane, using FR24 to confirm the distance?

[neil9327]

I was in the 2nd-floor restaurant of John Lewis in Southampton yesterday at around 5pm, soon after sunset, Far away to the west was a distant jetsteam of an approaching plane, and FR24 on my netbook showed that it was an eastbound 747 just to the west of Exeter. 100 miles away.

What's the furthest away you've ever seen a plane. Any "higher bids" than 100 miles?

[Mike]

I live in Stockholm with great visibility i western direction and can see aircraft close to Swedish/Norwegian border, almost 350 km away, about 220 miles.

[Mike]

Fungus: If I understand the thread starter correct he/she was asking for the aircraft you have seen with your eyes, not the receiver

If you talk about receiver coverage, we have an antenna on the top of a ski mountain in Sweden that covers up to almost 500 km / 300 miles.

[Goldfynche]

From my home in Ilford Essex, about 9 miles from the centre of London. I have seen aircraft as far away as Canterbury in Kent.
I think this falls short of a hundred miles but in the right conditions, I believe one should be able to see aircraft actually crossing the English channel.

[neil9327]

I live in Stockholm with great visibility i western direction and can see aircraft close to Swedish/Norwegian border, almost 350 km away, about 220 miles.

Wow I think you've won the prize.

I've done some calculations, and found that for a plane flying at 35000 feet, observed from sea level, that plane will be theoretically visible on the horizon when it is located 229 miles away, and not visible further away because it will be below the horizon.
This is because of the curvature of the earth.

Calculation below:
Assuming that the earth is a perfect sphere (OK I know it's not..) of:

radius r = 6378 Km (from google)
height of plane h = 35000 feet = 10.668Km

The three lines between the centre of the earth, the observer, and the plane form a right angled triangle.
So using pythagoras, if d is the distance from the plane to the observer:

r^2 + d^2 = (r + h)^2

For the above figures this gives d = 369 Km = 229 miles.

The plane you saw must have been right on the horizon..


And following on from this, if you are observing from another plane also at 35000 feet, the theoretical distance will be doubled to 458 miles.
..of course you won't have access to FR24 unless you have an internet connection up there.

[jlsmith]

From my train near London Bridge, on a very clear morning recently, I could see planes crossing onto mainland Europe over Holland/Belgium which I think would be about 150 miles as the crow flies.

[Mike]

Wow I think you've won the prize.

I've done some calculations, and found that for a plane flying at 35000 feet, observed from sea level, that plane will be theoretically visible on the horizon when it is located 229 miles away, and not visible further away because it will be below the horizon.
This is because of the curvature of the earth.

Calculation below:
Assuming that the earth is a perfect sphere (OK I know it's not..) of:

radius r = 6378 Km (from google)
height of plane h = 35000 feet = 10.668Km

The three lines between the centre of the earth, the observer, and the plane form a right angled triangle.
So using pythagoras, if d is the distance from the plane to the observer:

r^2 + d^2 = (r + h)^2

For the above figures this gives d = 369 Km = 229 miles.

The plane you saw must have been right on the horizon..


And following on from this, if you are observing from another plane also at 35000 feet, the theoretical distance will be doubled to 458 miles.
..of course you won't have access to FR24 unless you have an internet connection up there.

I'm not observing from sea level, my house has the best location in the area. It's located about 70-80 meters above sea level, with completely free visibility i western direction. And the B747 I was following last summer, was flying on FL400 if I remember correct.

[neil9327]

I'm not observing from sea level, my house has the best location in the area. It's located about 70-80 meters above sea level, with completely free visibility i western direction. And the B747 I was following last summer, was flying on FL400 if I remember correct.

Well that's still pretty impressive.
At FL400 40,000 feet the maximum distance is 245 miles + 11 miles for the 80 meters = 256 miles.

[Anmer]

Bear in mind that an aircraft at 40,000 feet, 250 miles away would appear a few millimetres above the ground at the horizon. Even if it were contrailing I wouldn't expect to eyeball it.

However, a Mode-S receiver should be able to "see" the transmitted data and plot it on a map.

[Goldfynche]

And that is my problem. My horizon is invariably local neighbouring rooftops. But on the next clear sunny day I shall make a point of observing contrails heading away from me.
When I was in Scotland recently, not far from Stirling. Some of the contrails I saw were definitely south of the border.

[watcher]

The other day from here in Colchester i could visually still see the contrail of a plane which was in the Isle of Wight region...so about 120 miles i suppose.

[TCASAlert]

From my home in Mansfield, Nottinghamshire, on a very clear day I can see aircraft just before they hand over to Amsterdam ACC from Scottish Control, when they are overhead the North Sea to the north of Cromer, Norfolk. This is around 110 miles away. Looking to the west, I can generally see aircraft trailing as they cross the coast to the north of Liverpool, around 90 miles away. Theoretically, I should be able to see aircraft just off the Dutch coast, but it's never been that clear across that distance :-)

[Ognjen]

376.1 nm.jpg Far enough?

[Mike]

Here is my coverage About 350-400 km i western direction.



BTW, we plan to activate this coverage maps for feeders with the new software

[Ognjen]

Sorry Mike, I know this is off topic, but I did not quite understod how I can get new software?