Probably innocent, but curious...

RFSnoop

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Recently, on flightradar24, I noticed an image that looked like two overlapping aircraft on a northerly heading near the SC coast. The image attracted my attention when it continued to appear to be two aircraft overlapping for some time. The flightradar24 data indicated both were the exact same model aircraft (Cessna 210), but with different N-numbers. The N-numbers for each aircraft were similar except for two digits being reversed. Their serial numbers were completely different. Looking up the N-numbers in the FAA Registry, both came back as invalid. Looking up the serial numbers in the FAA Registry, the same aircraft model came back for both, with the two N-numbers as shown in flightradar24 data, but with different owners. I was reluctant to post this because I have let the N-numbers and serial numbers get away from me, but curiosity got the better of me. Any ideas?
 

NC1

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Hmmm. Conflicting information that leads to dead ends. It almost seems the two planes didn't want anybody to positively identify them.

Makes you think of drug running or human trafficking going on when things like that happen.
But there is always one of those *reasonable* explanations, of course.
 

ATCTech

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Did you happen to look at the FR24 data source for each target (ADS-B, MLAT, ATC Radar) and the Mode-S codes for each? It's very possible it was one aircraft but FR24 deciphering it as two discrete airframes from multiple methods - not uncommon, for example one from Mode-S (MLAT derived) or ADS-B and the other from the octal FAA radar track data. I always use FR24 in ADS-B mode only for that very reason and manually select other data sources only when necessary. (It's in the Options -> Visibility section but you probably know that already.)

Cheers!
 

Ravenkeeper

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Recently, on flightradar24, I noticed an image that looked like two overlapping aircraft on a northerly heading near the SC coast. The image attracted my attention when it continued to appear to be two aircraft overlapping for some time. The flightradar24 data indicated both were the exact same model aircraft (Cessna 210), but with different N-numbers. The N-numbers for each aircraft were similar except for two digits being reversed. Their serial numbers were completely different. Looking up the N-numbers in the FAA Registry, both came back as invalid. Looking up the serial numbers in the FAA Registry, the same aircraft model came back for both, with the two N-numbers as shown in flightradar24 data, but with different owners. I was reluctant to post this because I have let the N-numbers and serial numbers get away from me, but curiosity got the better of me. Any ideas?
Did you zoom in on them? They may have been in close formation with each other.
 

Ubbe

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I have seen something similar a couple of years ago. Two aircrafts with almost identical N numbers flying extremly close to each other. After a couple of hours they split and went in different directions. At that time I thought it was a delivery flight of new airplanes as their N numbers could not be found in the databases.

/Ubbe
 

RFSnoop

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Makes you think of drug running or human trafficking going on when things like that happen.
But there is always one of those *reasonable* explanations, of course.
I did not want my imagination to run away with me, but I admit I couldn't help but wonder if something suspicious was going on.
 

RFSnoop

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Did you happen to look at the FR24 data source for each target (ADS-B, MLAT, ATC Radar) and the Mode-S codes for each? It's very possible it was one aircraft but FR24 deciphering it as two discrete airframes from multiple methods - not uncommon, for example one from Mode-S (MLAT derived) or ADS-B and the other from the octal FAA radar track data. I always use FR24 in ADS-B mode only for that very reason and manually select other data sources only when necessary. (It's in the Options -> Visibility section but you probably know that already.)

Cheers!
I am new to FR24 and my knowledge of it very basic. I will check out the data mentioned in your post and try to educate myself as I fumble around. Thank you!
 

RFSnoop

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Did you zoom in on them? They may have been in close formation with each other.
I did zoom in on "them" but probably not enough. At no time did I see two discrete images, it always appeared like two aircraft squashed together. The aircraft descriptions, course, altitude, and airspeed remained identical.
 

ecps92

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What were the Tail #'s as well as the ADSB Hex Codes

Recently, on flightradar24, I noticed an image that looked like two overlapping aircraft on a northerly heading near the SC coast. The image attracted my attention when it continued to appear to be two aircraft overlapping for some time. The flightradar24 data indicated both were the exact same model aircraft (Cessna 210), but with different N-numbers. The N-numbers for each aircraft were similar except for two digits being reversed. Their serial numbers were completely different. Looking up the N-numbers in the FAA Registry, both came back as invalid. Looking up the serial numbers in the FAA Registry, the same aircraft model came back for both, with the two N-numbers as shown in flightradar24 data, but with different owners. I was reluctant to post this because I have let the N-numbers and serial numbers get away from me, but curiosity got the better of me. Any ideas?
 

RFSnoop

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Do you have a date and the approximate time ?
Sorry, my wife and I are traveling and that got lost in the shuffle. I cannot pin it down closer than, I think, a morning between 9/9 and 9/12. If I had not been distracted by other things, I would have have posted about it while I could provide the time and aircraft info.
 

RFSnoop

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I have seen something similar a couple of years ago. Two aircrafts with almost identical N numbers flying extremly close to each other. After a couple of hours they split and went in different directions. At that time I thought it was a delivery flight of new airplanes as their N numbers could not be found in the databases.

/Ubbe
That is a plausible explanation for what you saw, and probably something equally uninteresting applies to my mystery.
 

AirScan

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I think, a morning between 9/9 and 9/12.
Using the FR24 playback option the only C210, northbound, morning, near SC coast, between those dates, I could find was N732MW. Does that ring a bell ? Only shows one target though. Maybe the playback option reconciles the data somehow when multiple sources are used vs the live mode ?


C210.jpg
 

RFSnoop

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...N732MW. Does that ring a bell ? ...
No, what I can remember of the N-numbers is that the last two numerals of one was 0? and the other was ?0. The digit represented by "?" was the same on both aircraft. I say "both" aircraft, but I really doubt there were two aircraft with the same description, the curious similarity of N-numbers, in the same vicinity, same course, etc. It seems more likely to me that it was one aircraft misidentified somehow as two. No?
 
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AirScan

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It seems more likely to me that it was one aircraft misidentified somehow as two. No?
I agree that's most likely. I'm curious what it would look like in playback mode, but that is the only northbound C210 I could find between the 9th and 12th. Are you sure it was a C210 and when you say in the morning what time no earlier than, and any more detail on the location ? I'll check a couple more days out either side.
 

ATCTech

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Please open whatever browser you're using for FR24 and check the settings/visibility group and let us know what options are selected. As I said initially, if more than one option is selected then the display of dual targets from the same aircraft is not unusual. The "ident" displayed by FR24 can be derived from both what's entered by the flight crew (which is not seen by ATC, hence idents like "BROKE" or "FLY4FREE") or from the ATC flight plan. Only checking the Mode-S code of each target against the civil aircraft registration idents in the FAA database will determine the real registrations at play here. If the Mode-S codes were the same then it's 99.9% likely it was one aircraft displayed twice.

ATC flight data processing systems still use the assigned 4 digit Mode-C transponder octal code for correlating radar targets against flight plans so when 2 aircraft squawk the same Mode-C code it's flagged to ATC immediately. The aircraft-sourced Mode-S data tag is ignored.

Cheers!
 
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AirScan

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Probably this then. Playback always shows it as one aircraft. It descends out of coverage range for awhile and the target is lost, then reappears again as the aircraft climbs back up. Perhaps during this time the weaker signal scrambled the FR24 system somehow ?


C210.jpg
 

RFSnoop

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...Are you sure it was a C210 and when you say in the morning what time no earlier than, and any more detail on the location ?
Definitely a C210,. I'm thinking 9:00 - 11:00 AM local. When I was looking at it, it was northbound, just inshore, between Georgetown and Myrtle Beach, SC.
 
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