sensors Mode-S transponder

51108D

ICAO 24-bit transponder address · allocated to Estonia

Currently assigned to ES-PWC · AGUSTA AW-139

Hex
51108D
Octal
24210215
Decimal
5,312,653
Country
EE
Tail
ES-PWC
Type
A139
No current signal · last broadcast 19h ago
Flights observed
5
Distinct callsigns
1
Country
EE
Last broadcast
19h ago

Last known position

Most recent position reported by Mode-S 51108D.

Country allocation

The ICAO 24-bit address 51108D 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 1 distinct

Callsign Airline Flights Last seen
ESPWC - 5 2026-04-14

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-14 ESPWC TLL → TLL Apr 14, 08:10 UTCApr 14, 09:00 UTC50m
2026-04-13 ESPWC - Apr 13, 11:55 UTCApr 13, 12:15 UTC20m
2026-04-13 ESPWC TLL → TLL Apr 13, 11:10 UTCApr 13, 12:15 UTC1h 5m
2026-04-13 ESPWC - Apr 13, 08:30 UTCApr 13, 09:05 UTC35m
2026-04-13 ESPWC - Apr 13, 07:55 UTCApr 13, 08:15 UTC20m

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-PWC page for operator, model, and routing details .

Mode-S 51108D frequently asked

What is Mode-S code 51108D?
51108D is an ICAO 24-bit transponder address. Allocated to Estonia. Assigned to ES-PWC.
Where is Mode-S 51108D registered?
Mode-S code 51108D is allocated to Estonia (EE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 51108D broadcasting right now?
No active broadcast right now. Last signal was 19h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 51108D, octal 24210215, decimal 5,312,653.
What flights does 51108D operate?
Mode-S 51108D has broadcast 1 distinct callsign, including ESPWC.