Apparatus

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sensors Mode-S transponder

51104C

ICAO 24-bit transponder address · allocated to Estonia

Currently assigned to ES-PWB · AGUSTA AW-139

Hex
51104C
Octal
24210114
Decimal
5,312,588
Country
EE
Tail
ES-PWB
Type
A139
No current signal · last broadcast 8d ago
Flights observed
88
Distinct callsigns
2
Country
EE
Last broadcast
8d ago

Last known position

Most recent position reported by Mode-S 51104C.

Country allocation

The ICAO 24-bit address 51104C falls within the block assigned to Estonia (EE) by ICAO Annex 10, Volume III. Every aircraft registered in Estonia 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 2 distinct

Callsign Airline Flights Last seen
ESPWB - 87 2026-07-26
AGUST61 - 1 2026-06-16

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ESPWB - Jul 26, 05:40 UTCJul 26, 06:10 UTC30m
2026-07-26 ESPWB - Jul 26, 04:45 UTCJul 26, 05:05 UTC20m
2026-07-25 ESPWB - Jul 25, 22:10 UTCJul 25, 22:30 UTC20m
2026-07-25 ESPWB - Jul 25, 20:50 UTCJul 25, 21:10 UTC20m
2026-07-25 ESPWB TLL → TLL Jul 25, 10:55 UTCJul 25, 12:25 UTC1h 30m
2026-07-24 ESPWB - Jul 24, 11:40 UTCJul 24, 12:10 UTC30m
2026-07-24 ESPWB - Jul 24, 09:35 UTCJul 24, 09:55 UTC20m
2026-07-24 ESPWB TLL → TLL Jul 24, 08:00 UTCJul 24, 08:55 UTC55m
2026-07-22 ESPWB - Jul 22, 02:35 UTCJul 22, 02:55 UTC20m
2026-07-22 ESPWB - Jul 22, 01:40 UTCJul 22, 02:00 UTC20m
2026-07-21 ESPWB TLL → TLL Jul 21, 11:35 UTCJul 21, 12:50 UTC1h 15m
2026-07-20 ESPWB TLL → TLL Jul 20, 15:35 UTCJul 20, 16:25 UTC50m
2026-07-20 ESPWB - Jul 20, 12:10 UTCJul 20, 13:40 UTC1h 30m
2026-07-19 ESPWB - Jul 19, 22:15 UTCJul 19, 22:55 UTC40m
2026-07-19 ESPWB - Jul 19, 20:10 UTCJul 19, 20:30 UTC20m
2026-07-19 ESPWB - Jul 19, 14:00 UTCJul 19, 14:20 UTC20m
2026-07-19 ESPWB - Jul 19, 12:45 UTCJul 19, 13:05 UTC20m
2026-07-19 ESPWB TLL → TLL Jul 19, 08:05 UTCJul 19, 09:05 UTC1h 0m
2026-07-18 ESPWB - Jul 18, 14:30 UTCJul 18, 15:10 UTC40m
2026-07-18 ESPWB - Jul 18, 10:55 UTCJul 18, 11:50 UTC55m
2026-07-18 ESPWB TLL → TLL Jul 18, 08:55 UTCJul 18, 09:50 UTC55m
2026-07-17 ESPWB TLL → TLL Jul 17, 14:20 UTCJul 17, 15:40 UTC1h 20m
2026-07-17 ESPWB - Jul 17, 08:40 UTCJul 17, 09:15 UTC35m
2026-07-16 ESPWB - Jul 16, 18:34 UTCJul 16, 18:55 UTC20m
2026-07-16 ESPWB - Jul 16, 10:55 UTCJul 16, 12:09 UTC1h 15m
2026-07-15 ESPWB - Jul 15, 20:35 UTCJul 15, 21:20 UTC45m
2026-07-15 ESPWB TLL → TLL Jul 15, 08:00 UTCJul 15, 09:00 UTC1h 0m
2026-07-14 ESPWB - Jul 14, 12:20 UTCJul 14, 13:20 UTC1h 0m
2026-07-14 ESPWB TLL → TLL Jul 14, 09:25 UTCJul 14, 10:25 UTC1h 0m
2026-07-14 ESPWB TLL → TLL Jul 14, 07:30 UTCJul 14, 08:30 UTC1h 0m
2026-07-13 ESPWB TLL → TLL Jul 13, 12:10 UTCJul 13, 13:05 UTC55m
2026-07-12 ESPWB TLL → TLL Jul 12, 20:45 UTCJul 12, 21:50 UTC1h 5m
2026-07-12 ESPWB - Jul 12, 16:55 UTCJul 12, 17:30 UTC35m
2026-07-12 ESPWB - Jul 12, 13:10 UTCJul 12, 15:50 UTC2h 40m
2026-07-11 ESPWB - Jul 11, 15:00 UTCJul 11, 16:05 UTC1h 5m
2026-07-11 ESPWB TLL → TLL Jul 11, 10:40 UTCJul 11, 11:40 UTC1h 0m
2026-07-11 ESPWB TLL → TLL Jul 11, 08:01 UTCJul 11, 09:10 UTC1h 10m
2026-07-10 ESPWB TLL → TLL Jul 10, 13:55 UTCJul 10, 15:20 UTC1h 25m
2026-07-10 ESPWB TLL → TLL Jul 10, 11:40 UTCJul 10, 13:05 UTC1h 25m
2026-07-10 ESPWB - Jul 10, 08:40 UTCJul 10, 09:50 UTC1h 10m
2026-07-09 ESPWB TLL → TLL Jul 9, 20:55 UTCJul 9, 22:10 UTC1h 15m
2026-07-09 ESPWB - Jul 9, 16:05 UTCJul 9, 16:50 UTC45m
2026-07-09 ESPWB TLL → TLL Jul 9, 08:50 UTCJul 9, 09:50 UTC1h 0m
2026-07-09 ESPWB - Jul 9, 04:25 UTCJul 9, 04:50 UTC25m
2026-07-09 ESPWB - Jul 9, 02:40 UTCJul 9, 02:55 UTC15m
2026-07-08 ESPWB CHE → TLL Jul 8, 08:10 UTCJul 8, 09:25 UTC1h 15m
2026-07-07 ESPWB - Jul 7, 13:00 UTCJul 7, 13:15 UTC15m
2026-07-07 ESPWB - Jul 7, 10:10 UTCJul 7, 10:55 UTC45m
2026-07-07 ESPWB TLL → TLL Jul 7, 07:55 UTCJul 7, 09:25 UTC1h 30m
2026-07-06 ESPWB TLL → TLL Jul 6, 13:25 UTCJul 6, 14:25 UTC1h 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 ES-PWB page for operator, model, and routing details .

Mode-S 51104C frequently asked

What is Mode-S code 51104C?
51104C is an ICAO 24-bit transponder address. Allocated to Estonia. Assigned to ES-PWB.
Where is Mode-S 51104C registered?
Mode-S code 51104C is allocated to Estonia (EE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 51104C broadcasting right now?
No active broadcast right now. Last signal was 8d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 51104C, octal 24210114, decimal 5,312,588.
What flights does 51104C operate?
Mode-S 51104C has broadcast 2 distinct callsigns, including ESPWB, AGUST61.