sensors Mode-S transponder

503D3D

ICAO 24-bit transponder address · allocated to Lithuania

Currently assigned to LY-UNO · BOEING 737-800

Hex
503D3D
Octal
24036475
Decimal
5,258,557
Country
LT
Tail
LY-UNO
Type
B738
Broadcasting now · callsign SZN305 · 37,000 ft
Flights observed
11
Distinct callsigns
6
Country
LT
Last broadcast
22h ago

Current position

503D3D is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 503D3D 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 6 distinct

Callsign Airline Flights Last seen
SZN405 - 3 2026-04-14
SZN1005 - 3 2026-04-13
SZN209 Air Senegal 2 2026-04-13
SZN332 - 1 2026-04-13
SZN331 - 1 2026-04-13
SZN105 - 1 2026-04-12

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 SZN405 - Apr 14, 09:10 UTCApr 14, 09:35 UTC25m
2026-04-14 SZN405 - Apr 14, 07:10 UTCApr 14, 09:05 UTC1h 55m
2026-04-14 SZN405 - Apr 14, 06:35 UTCApr 14, 07:10 UTC35m
2026-04-13 SZN209 DSS → CKY Apr 13, 22:05 UTCApr 13, 22:40 UTC35m
2026-04-13 SZN1005 - Apr 13, 20:05 UTCApr 13, 20:25 UTC20m
2026-04-13 SZN1005 CSK → BJL Apr 13, 18:15 UTCApr 13, 18:30 UTC15m
2026-04-13 SZN1005 - Apr 13, 15:45 UTCApr 13, 16:05 UTC20m
2026-04-13 SZN332 - Apr 13, 12:50 UTCApr 13, 13:20 UTC30m
2026-04-13 SZN331 - Apr 13, 05:55 UTCApr 13, 06:15 UTC20m
2026-04-12 SZN209 DSS → CKY Apr 12, 19:05 UTCApr 12, 19:45 UTC40m
2026-04-12 SZN105 - Apr 12, 17:15 UTCApr 12, 17:30 UTC15m

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

Mode-S 503D3D frequently asked

What is Mode-S code 503D3D?
503D3D is an ICAO 24-bit transponder address. Allocated to Lithuania. Assigned to LY-UNO.
Where is Mode-S 503D3D registered?
Mode-S code 503D3D is allocated to Lithuania (LT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 503D3D broadcasting right now?
Yes. Mode-S 503D3D is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 503D3D, octal 24036475, decimal 5,258,557.
What flights does 503D3D operate?
Mode-S 503D3D has broadcast 6 distinct callsigns, including SZN405, SZN1005, SZN209, SZN332, SZN331.