sensors Mode-S transponder

4D21F2

ICAO 24-bit transponder address · allocated to Malta

Currently assigned to 9H-QAJ · BOEING 737-800

Hex
4D21F2
Octal
23220762
Decimal
5,054,962
Country
MT
Tail
9H-QAJ
Type
B738
No current signal · last broadcast 8h ago
Flights observed
552
Distinct callsigns
20
Country
MT
Last broadcast
8h ago

Last known position

Most recent position reported by Mode-S 4D21F2.

Country allocation

The ICAO 24-bit address 4D21F2 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 20 distinct

Callsign Airline Flights Last seen
RYR6AX - 6 2026-04-16
RYR11FB - 6 2026-04-16
RYR99TR - 5 2026-04-17
RYR4CT - 4 2026-04-13
RYR448 Ryanair 4 2026-06-14
RYR32AE - 4 2026-06-14
RYR29BC - 4 2026-06-29
RYR17XU - 4 2026-06-29
RYR96VR - 3 2026-07-11
RYR95KE Ryanair 3 2026-06-18
RYR898 Ryanair 3 2026-06-15
RYR74SB Ryanair 3 2026-06-12
RYR720F - 3 2026-06-30
RYR6BM - 3 2026-07-11
RYR5G Ryanair 3 2026-05-17
RYR59QZ Ryanair 3 2026-06-12
RYR57HT - 3 2026-06-18
RYR56DW Ryanair 3 2026-05-17
RYR562P Ryanair 3 2026-06-15
RYR3VU Ryanair 3 2026-05-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 RYR1NK - Jul 14, 22:00 UTCJul 14, 22:50 UTC49m
2026-07-14 RYR8274 FAO → OPO Jul 14, 20:35 UTCJul 14, 21:15 UTC40m
2026-07-14 RYR81SU - Jul 14, 17:15 UTCJul 14, 19:45 UTC2h 30m
2026-07-14 RYR22EY FAO → LTN Jul 14, 12:45 UTCJul 14, 15:10 UTC2h 25m
2026-07-14 RYR1WB - Jul 14, 08:50 UTCJul 14, 11:50 UTC3h 0m
2026-07-14 RYR39QA FAO → NRN Jul 14, 05:35 UTCJul 14, 08:05 UTC2h 30m
2026-07-13 RYR9CD NWI → FAO Jul 13, 18:25 UTCJul 13, 21:05 UTC2h 40m
2026-07-13 RYR952H FAO → NWI Jul 13, 14:45 UTCJul 13, 17:10 UTC2h 25m
2026-07-13 RYR6LY - Jul 13, 11:00 UTCJul 13, 13:50 UTC2h 50m
2026-07-13 RYR78UE - Jul 13, 07:15 UTCJul 13, 09:50 UTC2h 35m
2026-07-12 RYR52NP - Jul 12, 17:45 UTCJul 12, 21:35 UTC3h 50m
2026-07-12 RYR6WJ VNO → TRN Jul 12, 13:10 UTCJul 12, 16:35 UTC3h 25m
2026-07-12 RYR3VD MAN → FAO Jul 12, 09:10 UTCJul 12, 11:55 UTC2h 45m
2026-07-12 RYR63PR FAO → MAN Jul 12, 05:45 UTCJul 12, 08:10 UTC2h 25m
2026-07-11 RYR96VR ABZ → FAO Jul 11, 18:05 UTCJul 11, 21:10 UTC3h 5m
2026-07-11 RYR6BM FAO → ABZ Jul 11, 14:00 UTCJul 11, 16:50 UTC2h 50m
2026-07-11 RYR47NY BOH → FAO Jul 11, 09:50 UTCJul 11, 12:10 UTC2h 20m
2026-07-11 RYR80XD FAO → BOH Jul 11, 06:40 UTCJul 11, 08:50 UTC2h 10m
2026-07-10 RYR21PC ORK → FAO Jul 10, 20:10 UTCJul 10, 22:20 UTC2h 10m
2026-07-10 RYR31FW - Jul 10, 16:55 UTCJul 10, 19:05 UTC2h 10m
2026-07-10 RYR47NY BOH → FAO Jul 10, 13:45 UTCJul 10, 15:55 UTC2h 10m
2026-07-10 RYR80XD FAO → BOH Jul 10, 10:35 UTCJul 10, 12:50 UTC2h 15m
2026-07-10 RYR322N - Jul 10, 08:55 UTCJul 10, 09:45 UTC50m
2026-07-10 RYR17JX - Jul 10, 07:15 UTCJul 10, 08:05 UTC50m
2026-07-09 RYR8JH - Jul 9, 19:05 UTCJul 9, 21:45 UTC2h 40m
2026-07-09 RYR96PA FAO → NCL Jul 9, 15:40 UTCJul 9, 18:20 UTC2h 40m
2026-07-09 RYR96VR ABZ → FAO Jul 9, 11:15 UTCJul 9, 14:20 UTC3h 5m
2026-07-09 RYR6BM FAO → ABZ Jul 9, 06:05 UTCJul 9, 09:10 UTC3h 5m
2026-07-08 RYR22FC VIE → FAO Jul 8, 18:50 UTCJul 8, 21:50 UTC3h 0m
2026-07-08 RYR776Q FAO → VIE Jul 8, 14:45 UTCJul 8, 17:55 UTC3h 10m
2026-07-08 RYR9CD - Jul 8, 10:40 UTCJul 8, 13:15 UTC2h 35m
2026-07-08 RYR952H FAO → NWI Jul 8, 07:00 UTCJul 8, 09:40 UTC2h 40m
2026-07-07 RYR3HC - Jul 7, 19:10 UTCJul 7, 21:35 UTC2h 25m
2026-07-07 RYR21FN FAO → CRL Jul 7, 15:55 UTCJul 7, 18:25 UTC2h 30m
2026-07-07 RYR8EA EIN → MAN Jul 7, 12:30 UTCJul 7, 15:00 UTC2h 30m
2026-07-07 RYR9131 FAO → MAN Jul 7, 09:00 UTCJul 7, 11:35 UTC2h 35m
2026-07-07 RYR322N OPO → FAO Jul 7, 07:20 UTCJul 7, 08:10 UTC50m
2026-07-07 RYR17JX FAO → OPO Jul 7, 05:30 UTCJul 7, 06:15 UTC45m
2026-07-06 RYR69UN LPL → FAO Jul 6, 20:10 UTCJul 6, 22:35 UTC2h 25m
2026-07-06 RYR94BQ FAO → LPL Jul 6, 16:45 UTCJul 6, 19:15 UTC2h 30m
2026-07-06 RYR10QM - Jul 6, 04:40 UTCJul 6, 07:05 UTC2h 25m
2026-07-05 RYR80ND - Jul 5, 18:50 UTCJul 5, 21:00 UTC2h 10m
2026-07-05 RYR8342 - Jul 5, 15:45 UTCJul 5, 17:30 UTC1h 45m
2026-07-05 RYR8443 ALC → ARN Jul 5, 13:00 UTCJul 5, 14:55 UTC1h 55m
2026-07-05 RYR27ZC - Jul 5, 09:40 UTCJul 5, 11:30 UTC1h 50m
2026-07-05 RYR48XY - Jul 5, 07:00 UTCJul 5, 08:35 UTC1h 35m
2026-07-05 RYR93QL - Jul 5, 04:45 UTCJul 5, 05:55 UTC1h 10m
2026-07-04 RYR7H - Jul 4, 19:00 UTCJul 4, 20:15 UTC1h 15m
2026-07-04 RYR12YP - Jul 4, 17:05 UTCJul 4, 18:15 UTC1h 10m
2026-07-04 RYR6B - Jul 4, 14:00 UTCJul 4, 16:20 UTC2h 20m

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

Mode-S 4D21F2 frequently asked

What is Mode-S code 4D21F2?
4D21F2 is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-QAJ.
Where is Mode-S 4D21F2 registered?
Mode-S code 4D21F2 is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D21F2 broadcasting right now?
No active broadcast right now. Last signal was 8h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D21F2, octal 23220762, decimal 5,054,962.
What flights does 4D21F2 operate?
Mode-S 4D21F2 has broadcast 20 distinct callsigns, including RYR6AX, RYR11FB, RYR99TR, RYR4CT, RYR448.