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sensors Mode-S transponder

4BD421

ICAO 24-bit transponder address · allocated to Turkey

Currently assigned to TC-UKK

Hex
4BD421
Octal
22752041
Decimal
4,969,505
Country
TR
Tail
TC-UKK
Type
BR23
No current signal · last broadcast 6d ago
Flights observed
108
Distinct callsigns
1
Country
TR
Last broadcast
6d ago

Last known position

Most recent position reported by Mode-S 4BD421.

Country allocation

The ICAO 24-bit address 4BD421 falls within the block assigned to Turkey (TR) by ICAO Annex 10, Volume III. Every aircraft registered in Turkey receives a permanent address from this block at the time of registration; the address stays with the airframe even if the aircraft is re-registered to a different operator within the country.

Callsign history 1 distinct

Callsign Airline Flights Last seen
TCUKK - 108 2026-07-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-11 TCUKK - Jul 11, 05:55 UTCJul 11, 06:45 UTC50m
2026-07-11 TCUKK - Jul 11, 03:15 UTCJul 11, 03:40 UTC25m
2026-07-10 TCUKK - Jul 10, 03:50 UTCJul 10, 07:40 UTC3h 50m
2026-07-08 TCUKK - Jul 8, 07:00 UTCJul 8, 08:50 UTC1h 50m
2026-07-07 TCUKK - Jul 7, 04:25 UTCJul 7, 07:25 UTC3h 0m
2026-07-07 TCUKK - Jul 7, 03:00 UTCJul 7, 03:55 UTC55m
2026-07-06 TCUKK - Jul 6, 06:50 UTCJul 6, 10:05 UTC3h 15m
2026-07-05 TCUKK - Jul 5, 03:40 UTCJul 5, 06:15 UTC2h 35m
2026-07-04 TCUKK - Jul 4, 03:40 UTCJul 4, 04:15 UTC35m
2026-07-02 TCUKK - Jul 2, 02:55 UTCJul 2, 05:35 UTC2h 40m
2026-06-29 TCUKK - Jun 29, 05:15 UTCJun 29, 06:34 UTC1h 20m
2026-06-29 TCUKK - Jun 29, 03:14 UTCJun 29, 04:34 UTC1h 20m
2026-06-27 TCUKK - Jun 27, 07:30 UTCJun 27, 09:00 UTC1h 30m
2026-06-27 TCUKK - Jun 27, 03:40 UTCJun 27, 05:39 UTC2h 0m
2026-06-26 TCUKK - Jun 26, 06:09 UTCJun 26, 06:39 UTC30m
2026-06-26 TCUKK - Jun 26, 04:34 UTCJun 26, 05:10 UTC35m
2026-06-26 TCUKK - Jun 26, 03:05 UTCJun 26, 03:54 UTC50m
2026-06-25 TCUKK - Jun 25, 09:14 UTCJun 25, 10:09 UTC55m
2026-06-25 TCUKK - Jun 25, 06:25 UTCJun 25, 06:55 UTC30m
2026-06-25 TCUKK - Jun 25, 04:45 UTCJun 25, 05:20 UTC35m
2026-06-25 TCUKK - Jun 25, 03:20 UTCJun 25, 03:59 UTC40m
2026-06-24 TCUKK - Jun 24, 07:05 UTCJun 24, 08:49 UTC1h 45m
2026-06-24 TCUKK - Jun 24, 05:05 UTCJun 24, 05:40 UTC35m
2026-06-24 TCUKK - Jun 24, 03:35 UTCJun 24, 04:34 UTC1h 0m
2026-06-23 TCUKK - Jun 23, 07:29 UTCJun 23, 09:09 UTC1h 40m
2026-06-23 TCUKK - Jun 23, 03:39 UTCJun 23, 05:24 UTC1h 45m
2026-06-22 TCUKK - Jun 22, 03:14 UTCJun 22, 03:35 UTC20m
2026-06-21 TCUKK - Jun 21, 12:14 UTCJun 21, 13:09 UTC55m
2026-06-21 TCUKK - Jun 21, 09:10 UTCJun 21, 10:04 UTC55m
2026-06-21 TCUKK - Jun 21, 06:04 UTCJun 21, 06:50 UTC45m
2026-06-21 TCUKK - Jun 21, 03:10 UTCJun 21, 03:19 UTC10m
2026-06-18 TCUKK - Jun 18, 03:10 UTCJun 18, 05:45 UTC2h 35m
2026-06-17 TCUKK - Jun 17, 13:00 UTCJun 17, 13:25 UTC25m
2026-06-17 TCUKK - Jun 17, 06:20 UTCJun 17, 07:20 UTC1h 0m
2026-06-17 TCUKK - Jun 17, 02:40 UTCJun 17, 04:45 UTC2h 5m
2026-06-16 TCUKK - Jun 16, 08:25 UTCJun 16, 09:10 UTC45m
2026-06-16 TCUKK - Jun 16, 07:15 UTCJun 16, 07:55 UTC40m
2026-06-16 TCUKK - Jun 16, 05:25 UTCJun 16, 05:55 UTC30m
2026-06-16 TCUKK - Jun 16, 04:00 UTCJun 16, 04:55 UTC55m
2026-06-15 TCUKK - Jun 15, 07:00 UTCJun 15, 08:49 UTC1h 50m
2026-06-15 TCUKK - Jun 15, 03:35 UTCJun 15, 05:45 UTC2h 10m
2026-06-12 TCUKK - Jun 12, 06:50 UTCJun 12, 07:25 UTC35m
2026-06-12 TCUKK - Jun 12, 04:45 UTCJun 12, 05:20 UTC35m
2026-06-11 TCUKK - Jun 11, 05:35 UTCJun 11, 06:00 UTC25m
2026-06-10 TCUKK - Jun 10, 06:35 UTCJun 10, 10:25 UTC3h 50m
2026-06-07 TCUKK - Jun 7, 11:35 UTCJun 7, 11:50 UTC15m
2026-06-04 TCUKK - Jun 4, 10:00 UTCJun 4, 12:00 UTC2h 0m
2026-06-03 TCUKK - Jun 3, 10:00 UTCJun 3, 15:05 UTC5h 5m
2026-06-02 TCUKK - Jun 2, 09:05 UTCJun 2, 09:15 UTC10m
2026-06-01 TCUKK - Jun 1, 05:50 UTCJun 1, 07:00 UTC1h 10m

About Mode-S

A Mode-S transponder code (also called an "ICAO 24-bit address" or "hex code") is a 6-character hexadecimal identifier permanently assigned to an aircraft when it's first registered. Unlike callsigns (which change with each flight) or registrations (which can change if an aircraft is sold internationally), the Mode-S address stays with the airframe for the life of the aircraft in that country.

Every ADS-B transmission from an aircraft includes its Mode-S address, making it the most reliable way to identify a specific airframe. Flight-tracking services like Apparatus use the Mode-S address as the primary key for tying position broadcasts, callsigns, and ownership records together.

Prefer a tail-number view? See the TC-UKK page for operator, model, and routing details .

Mode-S 4BD421 frequently asked

What is Mode-S code 4BD421?
4BD421 is an ICAO 24-bit transponder address. Allocated to Turkey. Assigned to TC-UKK.
Where is Mode-S 4BD421 registered?
Mode-S code 4BD421 is allocated to Turkey (TR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4BD421 broadcasting right now?
No active broadcast right now. Last signal was 6d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4BD421, octal 22752041, decimal 4,969,505.
What flights does 4BD421 operate?
Mode-S 4BD421 has broadcast 1 distinct callsign, including TCUKK.