sensors Mode-S transponder

503CAA

ICAO 24-bit transponder address · allocated to Lithuania

Currently assigned to LY-HJB · AEROSPATIALE AS-355 Ecureuil 2

Hex
503CAA
Octal
24036252
Decimal
5,258,410
Country
LT
Tail
LY-HJB
Type
AS55
No current signal · last broadcast 2d ago
Flights observed
3
Distinct callsigns
2
Country
LT
Last broadcast
2d ago

Last known position

Most recent position reported by Mode-S 503CAA.

Country allocation

The ICAO 24-bit address 503CAA falls within the block assigned to Lithuania (LT) by ICAO Annex 10, Volume III. Every aircraft registered in Lithuania 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
GJT7XU Gestion Aerea Ajecutiva 2 2026-05-16
GJT57X - 1 2026-05-27

Recent flights last 3

DateFlightRouteTakeoffLandingDuration
2026-05-27 GJT57X - May 27, 12:50 UTCMay 27, 13:10 UTC20m
2026-05-16 GJT7XU AYT → VNO May 16, 11:01 UTCMay 16, 11:16 UTC15m
2026-05-15 GJT7XU AYT → VNO May 15, 12:50 UTCMay 16, 11:16 UTC22h 25m

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 LY-HJB page for operator, model, and routing details .

Mode-S 503CAA frequently asked

What is Mode-S code 503CAA?
503CAA is an ICAO 24-bit transponder address. Allocated to Lithuania. Assigned to LY-HJB.
Where is Mode-S 503CAA registered?
Mode-S code 503CAA is allocated to Lithuania (LT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 503CAA broadcasting right now?
No active broadcast right now. Last signal was 2d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 503CAA, octal 24036252, decimal 5,258,410.
What flights does 503CAA operate?
Mode-S 503CAA has broadcast 2 distinct callsigns, including GJT7XU, GJT57X.