Flightradar24 question

[Octane]

I was tracking a Bizjet with known registration but private destination and owner details. I predicted the destination but it disappeared off Flightradar24 completely. Would this suggest security precautions due VVIP flight?
Thanks

[SpringHeeledJack]

Maybe they turn off M-LAT or whatever under a certain altitude for their own reasons, whatever they may be ? I notice that certain aircraft are visible on some tracker, yet on others empty space. Who knows why, not me, but I'm sure someone will be along with a detailed explanation soon enough :-)

[jmmoric]

One of the most insecure systems ever invented.....

[Dave Gittins]

Tracking systems are a compete mystery to me. Remember being in Barbados a few years ago when FR 24 had some flights and Planefinder had others and some appeared on both. Never found out why.

Similarly last week in Madeira looking at Shipfinder, Cruise Ship Tracker and FleetMon to see what was coming into harbour and it was a compete arbitrary mix what appears on what tracker and occasionally 100,000 tones would appear with no warning at all.

[DaveReidUK]

Maybe they turn off M-LAT or whatever under a certain altitude for their own reasons, whatever they may be ?

Multilateration is progressively more difficult to achieve as altitude decreases, as it depends on the aircraft's transmissions being received simultaneously by several different ground stations, and that requires line-of-sight from each of them.

One of the most insecure systems ever invented.....

Are you talking about MLat? Or ADS-B/Mode S in general ?

[jmmoric]

Are you talking about MLat? Or ADS-B/Mode S in general ?

ADS-B...

MLAT is great :)

[N707ZS]

Perhaps the jet landed at an airport not covered by a contributor to FR24. At Teesside airport a contributor turns his equipment off so aircraft disappear once they get to a certain height.

[DaveReidUK]

ADS-B...

MLAT is great :)

Fair enough.

In my experience ADS-B is pretty good, too, but if yours is mostly via FR24 I can understand your misgivings.

[377 Pete]

...but it disappeared off Flightradar24 completely. Would this suggest security precautions due VVIP flight?
Thanks

FR24 will block A/C info ( Mode-s hexcode, tail#, reg., owner/operator info, etc.) on request, but in this case, I think line-of-sight with a ground station was lost, which is very common in areas where there are sparse volunteer ground stations.

[Octane]

FR24 will block A/C info ( Mode-s hexcode, tail#, reg., owner/operator info, etc.) on request, but in this case, I think line-of-sight with a ground station was lost, which is very common in areas where there are sparse volunteer ground stations.

The other aircraft in the vicinity on the same route remained on screen until landing. That's why I was wondering if it was a security reason to hide the destination..

Thank you for your replies :-)

[DaveReidUK]

The other aircraft in the vicinity on the same route remained on screen until landing.

It's likely then (see explanations above) that the aircraft that remained on your screen was sending ADS-B data (and hence only needed to be picked up by one station on the ground to establish its position) and the aircraft that disappeared was only sending Mode S (and therefore could only be plotted while being picked up simultaneously by several ground stations).

Nothing to do with being blocked (in that case, FR24 wouldn't show the aircraft at all).

[Peter47]

In my experience FR24 is not bad with passenger flights but poorer with biz jets and cargo flights. With the last flights often appear multiple times often with unknown against some of them. I don['t know if anyone knows what the problem is. It could be a lack of data from airline and airport sources and confusion with triangular (or more complicated) patterns where a sector may carry the number of the inbound or outbound flight.

[N707ZS]

The flight tracker seems to have gone off line this morning after slowing down, is it everyone watching Ukraine.

[DaveReidUK]

The flight tracker seems to have gone off line this morning after slowing down, is it everyone watching Ukraine.

Unsurprisingly, it would appear so.

[N707ZS]

Thanks Dave, first finger pointed at Virgin, too many kids on the internet for school holidays, but no the speed test was ok.

[horatio_b]

The FAA have an option (LADD) for flight tracking data to be blocked on application, usually from owners of N-registered executive jets
Ironically, ADS-B, which states it does not block anything, has an LADD filter which allows the display of just these aircraft which are blocked by FR24 and other trackers.

[SpringHeeledJack]

When I looked a while ago Cloudflare was giving me a 7-minute waiting time for FR24 b before seeing the site and moments later I was blocked just like that! As mentioned they must be overwhelmed today as perhaps the most well known of the trackers.

[DaveReidUK]

Ironically, ADS-B, which states it does not block anything, has an LADD filter which allows the display of just these aircraft which are blocked by FR24 and other trackers.

ADS-B contains no built-in filters. Any aircraft transmitting ADS-B can be picked up by any ADS-B receiver within range. Or are you referring to filters at the flight trackers?

[horatio_b]

On the right hand side of the adsbexchange.com display there are a number of optional filters. One will restrict to military aircraft. Another "LADD" will only show aircraft blocked by FR24 etc. This filter will probably only show half a dozen aircraft over the whole of Europe.

[DaveReidUK]

Thanks for the clarification, makes sense now.

[SpringHeeledJack]

At the moment we are able to see military aircraft NOT belonging to Russia in the conflict zone. well most of them, as I'm sure some are incognito.

Is it that all Russian airframes are operating with jammers, or some other blocking tech ? There are several surveillance airframes going up and down the western border of Ukraine and Belarus, so they will know what's what in terms of the sky.

[DaveReidUK]

At the moment we are able to see military aircraft NOT belonging to Russia in the conflict zone. well most of them, as I'm sure some are incognito.

Is it that all Russian airframes are operating with jammers, or some other blocking tech ? There are several surveillance airframes going up and down the western border of Ukraine and Belarus, so they will know what's what in terms of the sky.

Several possible reasons, some or all of which may apply:

1) Russian aircraft flying combat missions don't feel the need to switch their transponders on

2) FR24 feeders in Ukraine have more pressing things on their minds at present

3) FR24 is voluntarily suppressing some information

Don't forget that, despite the name, FlightRadar24 isn't radar at all, it's essentially datacomms and relies on the participation of the targets.

[SpringHeeledJack]

All salient points, though I was referring to trackers, rather than just FR24. Regarding the Russian aircraft wouldn't they require some form of transponder, even if just a secure signal to show command where the chess pieces were, so to speak ?

[DaveReidUK]

Russian aircraft will almost certainly have IFF so they can avoid shooting each other down.

Whether they send anything on the frequency that FR24 feeders' receivers are hard-tuned to is another question, and even if they do, they certainly won't be broadcasting their position for the world to see.