sensors Mode-S transponder

4A4CA1

ICAO 24-bit transponder address · allocated to Romania

Currently assigned to YR-SEA · AIRBUS A-320

Hex
4A4CA1
Octal
22446241
Decimal
4,869,281
Country
RO
Tail
YR-SEA
Type
A320
Broadcasting now · callsign HYM044P · 34,000 ft
Flights observed
5
Distinct callsigns
5
Country
RO
Last broadcast
1h ago

Current position

4A4CA1 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 4A4CA1 falls within the block assigned to Romania (RO) by ICAO Annex 10, Volume III. Every aircraft registered in Romania 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 5 distinct

Callsign Airline Flights Last seen
SEK1214 - 1 2026-07-15
SEK1213 - 1 2026-07-15
SEK1212 - 1 2026-07-12
SEK1211 - 1 2026-07-12
HYM044P - 1 2026-07-16

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-07-16 HYM044P - Jul 16, 19:40 UTCJul 16, 20:15 UTC35m
2026-07-15 SEK1214 - Jul 15, 13:15 UTCJul 15, 16:00 UTC2h 45m
2026-07-15 SEK1213 - Jul 15, 08:15 UTCJul 15, 10:35 UTC2h 20m
2026-07-12 SEK1212 - Jul 12, 11:55 UTCJul 12, 15:40 UTC3h 45m
2026-07-12 SEK1211 - Jul 12, 07:20 UTCJul 12, 09:50 UTC2h 30m

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 YR-SEA page for operator, model, and routing details .

Mode-S 4A4CA1 frequently asked

What is Mode-S code 4A4CA1?
4A4CA1 is an ICAO 24-bit transponder address. Allocated to Romania. Assigned to YR-SEA.
Where is Mode-S 4A4CA1 registered?
Mode-S code 4A4CA1 is allocated to Romania (RO). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4A4CA1 broadcasting right now?
Yes. Mode-S 4A4CA1 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4A4CA1, octal 22446241, decimal 4,869,281.
What flights does 4A4CA1 operate?
Mode-S 4A4CA1 has broadcast 5 distinct callsigns, including SEK1214, SEK1213, SEK1212, SEK1211, HYM044P.