sensors Mode-S transponder

4A2023

ICAO 24-bit transponder address · allocated to Romania

Currently assigned to YR-HAC · AIRBUS A-320

Hex
4A2023
Octal
22420043
Decimal
4,857,891
Country
RO
Tail
YR-HAC
Type
A320
No current signal · last broadcast 6h ago
Flights observed
172
Distinct callsigns
20
Country
RO
Last broadcast
6h ago

Last known position

Most recent position reported by Mode-S 4A2023.

Country allocation

The ICAO 24-bit address 4A2023 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 20 distinct

Callsign Airline Flights Last seen
HLJ5GH - 17 2026-07-12
HLJ5AF - 17 2026-07-12
HLJ4AE - 17 2026-07-08
HLJ1CD - 17 2026-07-08
HLJ1AG - 12 2026-07-09
HLJ4AK - 11 2026-07-12
HLJ2NP - 11 2026-07-12
HLJ5AH - 10 2026-07-07
HLJ6AJ - 8 2026-07-11
HLJ1LP - 7 2026-07-11
HLJ5BC - 6 2026-07-09
HLJ6BD - 5 2026-07-07
HLJ133 - 3 2026-06-29
HLJ132 - 3 2026-06-29
HLJ7SZ - 2 2026-07-08
HLJ6WW - 2 2026-07-08
HLJ220 - 2 2026-07-10
HLJ219 - 2 2026-07-10
HLJ153 - 2 2026-06-25
HLJ152 - 2 2026-06-25

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-12 HLJ4AK - Jul 12, 15:35 UTCJul 12, 17:45 UTC2h 10m
2026-07-12 HLJ2NP - Jul 12, 12:01 UTCJul 12, 13:55 UTC1h 55m
2026-07-12 HLJ5AF - Jul 12, 07:40 UTCJul 12, 10:01 UTC2h 20m
2026-07-12 HLJ5GH PRG → NBE Jul 12, 04:10 UTCJul 12, 06:20 UTC2h 10m
2026-07-11 HLJ6AJ - Jul 11, 09:45 UTCJul 11, 12:15 UTC2h 30m
2026-07-11 HLJ1LP PRG → DBB Jul 11, 04:10 UTCJul 11, 07:30 UTC3h 20m
2026-07-10 HLJ4AK MIR → PRG Jul 10, 14:20 UTCJul 10, 16:35 UTC2h 15m
2026-07-10 HLJ219 - Jul 10, 11:00 UTCJul 10, 13:00 UTC2h 0m
2026-07-10 HLJ220 - Jul 10, 07:30 UTCJul 10, 09:40 UTC2h 10m
2026-07-10 HLJ2NP - Jul 10, 04:20 UTCJul 10, 06:20 UTC2h 0m
2026-07-09 HLJ5AF - Jul 9, 17:15 UTCJul 9, 19:25 UTC2h 10m
2026-07-09 HLJ1AG - Jul 9, 14:05 UTCJul 9, 16:15 UTC2h 10m
2026-07-09 HLJ1AG - Jul 9, 12:45 UTCJul 9, 13:05 UTC20m
2026-07-09 HLJ5BC - Jul 9, 09:10 UTCJul 9, 11:10 UTC2h 0m
2026-07-09 HLJ5GH - Jul 9, 05:15 UTCJul 9, 07:10 UTC1h 55m
2026-07-08 HLJ4AE - Jul 8, 15:30 UTCJul 8, 18:00 UTC2h 30m
2026-07-08 HLJ7SZ - Jul 8, 11:40 UTCJul 8, 13:50 UTC2h 10m
2026-07-08 HLJ6WW - Jul 8, 07:50 UTCJul 8, 10:20 UTC2h 30m
2026-07-08 HLJ1CD PRG → DJE Jul 8, 04:15 UTCJul 8, 06:35 UTC2h 20m
2026-07-07 HLJ4AE DJE → PRG Jul 7, 16:35 UTCJul 7, 19:10 UTC2h 35m
2026-07-07 HLJ5AH - Jul 7, 13:05 UTCJul 7, 15:25 UTC2h 20m
2026-07-07 HLJ5AH - Jul 7, 11:05 UTCJul 7, 11:30 UTC25m
2026-07-07 HLJ6BD - Jul 7, 07:35 UTCJul 7, 10:00 UTC2h 25m
2026-07-07 HLJ1CD - Jul 7, 04:10 UTCJul 7, 06:20 UTC2h 10m
2026-07-06 HLJ5AF NBE → PRG Jul 6, 16:35 UTCJul 6, 18:45 UTC2h 10m
2026-07-06 HLJ1AG - Jul 6, 12:40 UTCJul 6, 14:35 UTC1h 55m
2026-07-06 HLJ1AG - Jul 6, 10:55 UTCJul 6, 11:25 UTC30m
2026-07-06 HLJ5BC - Jul 6, 08:00 UTCJul 6, 09:55 UTC1h 55m
2026-07-06 HLJ5GH - Jul 6, 04:20 UTCJul 6, 06:15 UTC1h 55m
2026-07-05 HLJ4AK - Jul 5, 15:40 UTCJul 5, 17:50 UTC2h 10m
2026-07-05 HLJ2NP - Jul 5, 11:55 UTCJul 5, 14:00 UTC2h 5m
2026-07-05 HLJ5AF - Jul 5, 07:50 UTCJul 5, 09:50 UTC2h 0m
2026-07-05 HLJ5GH - Jul 5, 04:15 UTCJul 5, 06:25 UTC2h 10m
2026-07-04 HLJ5AF NBE → PRG Jul 4, 17:15 UTCJul 4, 19:25 UTC2h 10m
2026-07-04 HLJ5GH PRG → NBE Jul 4, 13:50 UTCJul 4, 16:00 UTC2h 10m
2026-07-04 HLJ4AE - Jul 4, 08:40 UTCJul 4, 11:05 UTC2h 25m
2026-07-04 HLJ1CD - Jul 4, 04:50 UTCJul 4, 07:05 UTC2h 15m
2026-07-03 HLJ4AK - Jul 3, 14:45 UTCJul 3, 17:10 UTC2h 25m
2026-07-03 HLJ219 - Jul 3, 11:40 UTCJul 3, 13:30 UTC1h 50m
2026-07-03 HLJ220 - Jul 3, 07:40 UTCJul 3, 09:55 UTC2h 15m
2026-07-03 HLJ2NP - Jul 3, 04:20 UTCJul 3, 06:10 UTC1h 50m
2026-07-02 HLJ5AF - Jul 2, 17:05 UTCJul 2, 19:05 UTC2h 0m
2026-07-02 HLJ1AG - Jul 2, 13:45 UTCJul 2, 15:40 UTC1h 55m
2026-07-02 HLJ1AG - Jul 2, 12:35 UTCJul 2, 12:45 UTC10m
2026-07-02 HLJ5BC - Jul 2, 09:25 UTCJul 2, 11:15 UTC1h 50m
2026-07-02 HLJ5GH - Jul 2, 05:15 UTCJul 2, 07:15 UTC2h 0m
2026-07-01 HLJ4AE DJE → PRG Jul 1, 16:35 UTCJul 1, 18:55 UTC2h 20m
2026-07-01 HLJ7SZ PED → DJE Jul 1, 12:10 UTCJul 1, 14:40 UTC2h 30m
2026-07-01 HLJ6WW - Jul 1, 08:15 UTCJul 1, 10:35 UTC2h 20m
2026-07-01 HLJ1CD - Jul 1, 04:25 UTCJul 1, 06:40 UTC2h 15m

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

Mode-S 4A2023 frequently asked

What is Mode-S code 4A2023?
4A2023 is an ICAO 24-bit transponder address. Allocated to Romania. Assigned to YR-HAC.
Where is Mode-S 4A2023 registered?
Mode-S code 4A2023 is allocated to Romania (RO). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4A2023 broadcasting right now?
No active broadcast right now. Last signal was 6h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4A2023, octal 22420043, decimal 4,857,891.
What flights does 4A2023 operate?
Mode-S 4A2023 has broadcast 20 distinct callsigns, including HLJ5GH, HLJ5AF, HLJ4AE, HLJ1CD, HLJ1AG.