sensors Mode-S transponder

4D2503

ICAO 24-bit transponder address

Currently assigned to 9H-VVR · BOEING 737 MAX 8

Hex
4D2503
Octal
23222403
Decimal
5,055,747
Tail
9H-VVR
Type
B38M
No current signal · last broadcast 53m ago
Flights observed
6
Distinct callsigns
6
Country
-
Last broadcast
53m ago

Last known position

Most recent position reported by Mode-S 4D2503.

Callsign history 6 distinct

Callsign Airline Flights Last seen
RYR9PG Ryanair 1 2026-06-09
RYR77CN Ryanair 1 2026-06-09
RYR5XX Ryanair 1 2026-06-09
RYR4JQ Ryanair 1 2026-06-09
RYR3U Ryanair 1 2026-06-08
RYR3QE Ryanair 1 2026-06-09

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-06-09 RYR77CN BER → STN Jun 9, 20:05 UTCJun 9, 20:45 UTC40m
2026-06-09 RYR9PG STN → ORK Jun 9, 15:00 UTCJun 9, 18:20 UTC3h 20m
2026-06-09 RYR5XX BER → PSA Jun 9, 12:30 UTCJun 9, 14:05 UTC1h 35m
2026-06-09 RYR3QE PMO → BGY Jun 9, 08:50 UTCJun 9, 11:20 UTC2h 30m
2026-06-09 RYR4JQ EDI → BUD Jun 9, 04:40 UTCJun 9, 07:30 UTC2h 50m
2026-06-08 RYR3U STN → GRO Jun 8, 16:30 UTCJun 8, 17:55 UTC1h 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 9H-VVR page for operator, model, and routing details .

Mode-S 4D2503 frequently asked

What is Mode-S code 4D2503?
4D2503 is an ICAO 24-bit transponder address. Assigned to 9H-VVR.
Is 4D2503 broadcasting right now?
No active broadcast right now. Last signal was 53m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D2503, octal 23222403, decimal 5,055,747.
What flights does 4D2503 operate?
Mode-S 4D2503 has broadcast 6 distinct callsigns, including RYR9PG, RYR77CN, RYR5XX, RYR4JQ, RYR3U.