sensors Mode-S transponder

51113C

ICAO 24-bit transponder address · allocated to Estonia

Currently assigned to ES-NTA · ATR-42-500

Hex
51113C
Octal
24210474
Decimal
5,312,828
Country
EE
Tail
ES-NTA
Type
AT45
No current signal · last broadcast 16h ago
Flights observed
5
Distinct callsigns
4
Country
EE
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S 51113C.

Country allocation

The ICAO 24-bit address 51113C 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 4 distinct

Callsign Airline Flights Last seen
NYX201 NyxAir 2 2026-04-14
NYX208 - 1 2026-04-13
NYX207 NyxAir 1 2026-04-13
NYX202 - 1 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-14 NYX201 TLL → URE Apr 14, 05:45 UTCApr 14, 06:10 UTC25m
2026-04-13 NYX208 - Apr 13, 16:35 UTCApr 13, 17:00 UTC25m
2026-04-13 NYX207 TLL → URE Apr 13, 15:25 UTCApr 13, 15:50 UTC25m
2026-04-13 NYX202 - Apr 13, 05:55 UTCApr 13, 06:20 UTC25m
2026-04-13 NYX201 - Apr 13, 04:40 UTCApr 13, 05:00 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-NTA page for operator, model, and routing details .

Mode-S 51113C frequently asked

What is Mode-S code 51113C?
51113C is an ICAO 24-bit transponder address. Allocated to Estonia. Assigned to ES-NTA.
Where is Mode-S 51113C registered?
Mode-S code 51113C is allocated to Estonia (EE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 51113C broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 51113C, octal 24210474, decimal 5,312,828.
What flights does 51113C operate?
Mode-S 51113C has broadcast 4 distinct callsigns, including NYX201, NYX208, NYX207, NYX202.