sensors Mode-S transponder

503CB9

ICAO 24-bit transponder address · allocated to Lithuania

Currently assigned to LY-JMS · BOEING 737-500

Hex
503CB9
Octal
24036271
Decimal
5,258,425
Country
LT
Tail
LY-JMS
Type
B735
No current signal · last broadcast 1d ago
Flights observed
7
Distinct callsigns
5
Country
LT
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 503CB9.

Country allocation

The ICAO 24-bit address 503CB9 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 5 distinct

Callsign Airline Flights Last seen
KLJ6290 - 2 2026-04-14
KLJ6249 - 2 2026-04-15
KLJ6289 - 1 2026-04-13
KLJ6288 - 1 2026-04-13
KLJ6250 - 1 2026-04-17

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-17 KLJ6250 - Apr 17, 09:20 UTCApr 17, 11:15 UTC1h 55m
2026-04-15 KLJ6249 - Apr 15, 15:05 UTCApr 15, 16:15 UTC1h 10m
2026-04-15 KLJ6249 - Apr 15, 14:01 UTCApr 15, 14:55 UTC54m
2026-04-14 KLJ6290 - Apr 14, 18:55 UTCApr 14, 19:20 UTC25m
2026-04-14 KLJ6290 - Apr 14, 17:20 UTCApr 14, 18:45 UTC1h 25m
2026-04-13 KLJ6289 - Apr 13, 23:05 UTCApr 13, 23:35 UTC30m
2026-04-13 KLJ6288 - Apr 13, 10:45 UTCApr 13, 11:25 UTC40m

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

Mode-S 503CB9 frequently asked

What is Mode-S code 503CB9?
503CB9 is an ICAO 24-bit transponder address. Allocated to Lithuania. Assigned to LY-JMS.
Where is Mode-S 503CB9 registered?
Mode-S code 503CB9 is allocated to Lithuania (LT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 503CB9 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 503CB9, octal 24036271, decimal 5,258,425.
What flights does 503CB9 operate?
Mode-S 503CB9 has broadcast 5 distinct callsigns, including KLJ6290, KLJ6249, KLJ6289, KLJ6288, KLJ6250.