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sensors Mode-S transponder

3C4A21

ICAO 24-bit transponder address · allocated to Germany

Currently assigned to D-ABQA · DE HAVILLAND DHC-8-400 Dash 8

Hex
3C4A21
Octal
17045041
Decimal
3,951,137
Country
DE
Tail
D-ABQA
Type
DH8D
Broadcasting now · callsign DLH797 · 34,000 ft
Flights observed
158
Distinct callsigns
20
Country
DE
Last broadcast
6d ago

Current position

3C4A21 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 3C4A21 falls within the block assigned to Germany (DE) by ICAO Annex 10, Volume III. Every aircraft registered in Germany 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 20 distinct

Callsign Airline Flights Last seen
DLH753 Lufthansa 21 2026-07-19
DLH471 Lufthansa 14 2026-05-27
DLH470 Lufthansa 13 2026-05-27
DLH500 Lufthansa 12 2026-07-22
DLH761 Lufthansa 11 2026-07-25
DLH760 Lufthansa 11 2026-07-25
DLH478 Lufthansa 10 2026-07-24
DLH752 - 8 2026-07-19
DLH501 Lufthansa 8 2026-07-23
DLH479 Lufthansa 8 2026-07-24
DLH796 - 7 2026-07-13
DLH797 - 6 2026-07-13
DLH7JF - 5 2026-07-05
DLH107 - 5 2026-07-05
DLH6EE - 3 2026-06-30
DLH4MW Lufthansa 3 2026-06-30
DLH797D Lufthansa 2 2026-06-03
DLH729 Lufthansa 2 2026-07-22
DLH590 Lufthansa 2 2026-07-26
DLH728 Lufthansa 1 2026-07-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 DLH590 FRA → NBO Jul 26, 17:20 UTCJul 26, 17:30 UTC10m
2026-07-26 DLH590 FRA → NBO Jul 26, 09:55 UTCJul 26, 12:30 UTC2h 35m
2026-07-25 DLH761 DEL → FRA Jul 25, 21:40 UTCJul 26, 05:15 UTC7h 35m
2026-07-25 DLH760 FRA → DEL Jul 25, 12:05 UTCJul 25, 19:10 UTC7h 5m
2026-07-24 DLH479 YUL → FRA Jul 24, 22:45 UTCJul 25, 04:55 UTC6h 10m
2026-07-24 DLH478 FRA → YUL Jul 24, 13:00 UTCJul 24, 20:15 UTC7h 15m
2026-07-23 DLH501 GIG → MUC Jul 23, 19:30 UTCJul 24, 06:05 UTC10h 35m
2026-07-22 DLH500 MUC → GIG Jul 22, 20:45 UTCJul 23, 07:45 UTC11h 0m
2026-07-22 DLH729 PVG → FRA Jul 22, 12:20 UTCJul 22, 16:45 UTC4h 25m
2026-07-21 DLH729 PVG → FRA Jul 21, 16:20 UTCJul 22, 16:15 UTC23h 55m
2026-07-21 DLH728 FRA → PVG Jul 21, 14:20 UTCJul 22, 13:40 UTC23h 20m
2026-07-20 DLH761 DEL → FRA Jul 20, 21:40 UTCJul 21, 05:45 UTC8h 4m
2026-07-20 DLH760 FRA → DEL Jul 20, 12:30 UTCJul 20, 19:15 UTC6h 45m
2026-07-19 DLH753 HYD → FRA Jul 19, 12:20 UTCJul 20, 07:00 UTC18h 40m
2026-07-19 DLH752 FRA → FRA Jul 19, 12:05 UTCJul 20, 07:00 UTC18h 55m
2026-07-18 DLH753 HYD → FRA Jul 18, 12:20 UTCJul 19, 06:55 UTC18h 35m
2026-07-18 DLH753 HYD → FRA Jul 18, 11:55 UTCJul 19, 06:55 UTC19h 0m
2026-07-17 DLH501 - Jul 17, 19:45 UTCJul 18, 06:25 UTC10h 41m
2026-07-17 DLH500 MUC → GIG Jul 17, 08:04 UTCJul 17, 08:20 UTC15m
2026-07-16 DLH500 MUC → GIG Jul 16, 22:05 UTCJul 17, 07:14 UTC9h 10m
2026-07-16 DLH500 MUC → GIG Jul 16, 20:49 UTCJul 16, 22:00 UTC1h 10m
2026-07-15 DLH479 YUL → FRA Jul 15, 22:55 UTCJul 16, 05:30 UTC6h 35m
2026-07-15 DLH478 - Jul 15, 12:50 UTCJul 15, 19:55 UTC7h 5m
2026-07-14 DLH479 YUL → FRA Jul 14, 22:30 UTCJul 15, 05:05 UTC6h 34m
2026-07-14 DLH478 FRA → YUL Jul 14, 13:00 UTCJul 14, 20:00 UTC7h 0m
2026-07-13 DLH797 - Jul 13, 18:10 UTCJul 14, 04:30 UTC10h 20m
2026-07-13 DLH797 - Jul 13, 16:05 UTCJul 13, 16:20 UTC15m
2026-07-13 DLH796 - Jul 13, 06:30 UTCJul 13, 07:05 UTC35m
2026-07-12 DLH796 - Jul 12, 20:05 UTCJul 12, 23:40 UTC3h 35m
2026-07-11 DLH501 - Jul 11, 19:30 UTCJul 12, 05:55 UTC10h 25m
2026-07-10 DLH500 - Jul 10, 20:40 UTCJul 11, 08:10 UTC11h 30m
2026-07-08 DLH479 YUL → FRA Jul 8, 22:20 UTCJul 9, 04:55 UTC6h 35m
2026-07-08 DLH478 FRA → YUL Jul 8, 12:40 UTCJul 8, 19:50 UTC7h 10m
2026-07-07 DLH797 HKG → FRA Jul 7, 18:05 UTCJul 8, 04:10 UTC10h 5m
2026-07-07 DLH797 HKG → FRA Jul 7, 16:00 UTCJul 7, 16:20 UTC20m
2026-07-06 DLH796 FRA → HKG Jul 6, 20:00 UTCJul 7, 06:55 UTC10h 55m
2026-07-06 DLH4N - Jul 6, 15:40 UTCJul 6, 16:15 UTC35m
2026-07-06 DLH5YE - Jul 6, 13:30 UTCJul 6, 14:05 UTC35m
2026-07-06 DLH1RF - Jul 6, 10:25 UTCJul 6, 11:05 UTC40m
2026-07-06 DLH4LC - Jul 6, 08:30 UTCJul 6, 09:05 UTC35m
2026-07-05 DLH107 - Jul 5, 12:35 UTCJul 5, 13:15 UTC40m
2026-07-05 DLH7JF - Jul 5, 10:45 UTCJul 5, 11:15 UTC30m
2026-07-04 DLH753 - Jul 4, 12:20 UTCJul 5, 06:25 UTC18h 5m
2026-07-04 DLH752 FRA → HYD Jul 4, 11:30 UTCJul 5, 06:25 UTC18h 55m
2026-07-03 DLH761 - Jul 3, 21:50 UTCJul 4, 05:40 UTC7h 50m
2026-07-03 DLH760 FRA → DEL Jul 3, 11:55 UTCJul 3, 18:50 UTC6h 55m
2026-07-02 DLH753 - Jul 2, 12:20 UTCJul 3, 06:45 UTC18h 25m
2026-07-02 DLH753 - Jul 2, 11:35 UTCJul 3, 06:45 UTC19h 10m
2026-07-02 DLH761 - Jul 2, 00:25 UTCJul 2, 08:10 UTC7h 45m
2026-07-01 DLH760 FRA → DEL Jul 1, 15:00 UTCJul 1, 22:00 UTC7h 0m

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 D-ABQA page for operator, model, and routing details .

Mode-S 3C4A21 frequently asked

What is Mode-S code 3C4A21?
3C4A21 is an ICAO 24-bit transponder address. Allocated to Germany. Assigned to D-ABQA.
Where is Mode-S 3C4A21 registered?
Mode-S code 3C4A21 is allocated to Germany (DE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 3C4A21 broadcasting right now?
Yes. Mode-S 3C4A21 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 3C4A21, octal 17045041, decimal 3,951,137.
What flights does 3C4A21 operate?
Mode-S 3C4A21 has broadcast 20 distinct callsigns, including DLH753, DLH471, DLH470, DLH500, DLH761.