sensors Mode-S transponder

4D221B

ICAO 24-bit transponder address · allocated to Malta

Currently assigned to 9H-MPR · AGUSTA AW-109 Grand

Hex
4D221B
Octal
23221033
Decimal
5,055,003
Country
MT
Tail
9H-MPR
Type
A109
No current signal · last broadcast 3h ago
Flights observed
5
Distinct callsigns
3
Country
MT
Last broadcast
3h ago

Last known position

Most recent position reported by Mode-S 4D221B.

Country allocation

The ICAO 24-bit address 4D221B falls within the block assigned to Malta (MT) by ICAO Annex 10, Volume III. Every aircraft registered in Malta 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 3 distinct

Callsign Airline Flights Last seen
RYR98YP Ryanair 1 2026-05-19
RYR39MV Ryanair 1 2026-04-30
RYR3254 Ryanair 1 2026-05-23

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-05-23 RYR3254 BCN → XRY May 23, 14:55 UTCMay 23, 15:05 UTC10m
2026-05-22 - - May 22, 05:40 UTCMay 22, 05:50 UTC10m
2026-05-19 RYR98YP STN → MLA May 19, 14:20 UTCMay 19, 14:30 UTC10m
2026-05-04 - - May 4, 18:10 UTCMay 4, 18:20 UTC10m
2026-04-30 RYR39MV STN → AGP Apr 30, 19:40 UTCApr 30, 19:50 UTC10m

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

Mode-S 4D221B frequently asked

What is Mode-S code 4D221B?
4D221B is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-MPR.
Where is Mode-S 4D221B registered?
Mode-S code 4D221B is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D221B broadcasting right now?
No active broadcast right now. Last signal was 3h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D221B, octal 23221033, decimal 5,055,003.
What flights does 4D221B operate?
Mode-S 4D221B has broadcast 3 distinct callsigns, including RYR98YP, RYR39MV, RYR3254.