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
Broadcasting now · callsign RYR41CG · 37,000 ft
Flights observed
605
Distinct callsigns
20
Country
MT
Last broadcast
Jul 26, 21:55 UTC

Current position

4D21F2 is currently broadcasting. Map zoomed to live position.

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
RYR6WJ Ryanair 6 2026-07-26
RYR6AX - 6 2026-04-16
RYR52NP Ryanair 6 2026-07-26
RYR11FB - 6 2026-04-16
RYR99TR - 5 2026-04-17
RYR9CD - 4 2026-07-22
RYR96VR Ryanair 4 2026-07-25
RYR95KE - 4 2026-07-17
RYR6BM - 4 2026-07-25
RYR63PR Ryanair 4 2026-07-26
RYR57HT - 4 2026-07-17
RYR4CT - 4 2026-04-13
RYR448 Ryanair 4 2026-06-14
RYR3VD Ryanair 4 2026-07-26
RYR32AE - 4 2026-06-14
RYR29BC - 4 2026-06-29
RYR17XU - 4 2026-06-29
RYR952H Ryanair 3 2026-07-20
RYR898 Ryanair 3 2026-06-15
RYR81SU - 3 2026-07-24

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 RYR52NP WMI → FAO Jul 26, 18:10 UTCJul 26, 21:50 UTC3h 40m
2026-07-26 RYR6WJ VNO → TRN Jul 26, 13:30 UTCJul 26, 17:10 UTC3h 40m
2026-07-26 RYR3VD EDI → BER Jul 26, 10:00 UTCJul 26, 12:15 UTC2h 15m
2026-07-26 RYR63PR CRL → BLQ Jul 26, 06:15 UTCJul 26, 09:05 UTC2h 51m
2026-07-25 RYR96VR ABZ → FAO Jul 25, 18:15 UTCJul 25, 21:00 UTC2h 45m
2026-07-25 RYR6BM FAO → ABZ Jul 25, 13:55 UTCJul 25, 17:10 UTC3h 15m
2026-07-25 RYR4W MAH → DUB Jul 25, 09:00 UTCJul 25, 11:15 UTC2h 15m
2026-07-25 RYR59JH FAO → STN Jul 25, 05:25 UTCJul 25, 07:45 UTC2h 20m
2026-07-24 RYR16SQ - Jul 24, 19:10 UTCJul 24, 21:50 UTC2h 40m
2026-07-24 RYR68MH - Jul 24, 15:40 UTCJul 24, 18:20 UTC2h 40m
2026-07-24 RYR81SU LTN → FAO Jul 24, 10:55 UTCJul 24, 13:25 UTC2h 30m
2026-07-24 RYR22EY FAO → LTN Jul 24, 07:45 UTCJul 24, 09:55 UTC2h 10m
2026-07-23 RYR52NP - Jul 23, 18:50 UTCJul 23, 22:25 UTC3h 35m
2026-07-23 RYR6WJ VNO → TRN Jul 23, 13:55 UTCJul 23, 17:50 UTC3h 55m
2026-07-23 RYR53AX SNN → FAO Jul 23, 09:50 UTCJul 23, 12:15 UTC2h 25m
2026-07-23 RYR2FM - Jul 23, 06:30 UTCJul 23, 08:40 UTC2h 10m
2026-07-22 RYR22FC DUB → CCF Jul 22, 18:50 UTCJul 22, 22:05 UTC3h 15m
2026-07-22 RYR776Q FAO → VIE Jul 22, 14:35 UTCJul 22, 17:35 UTC3h 0m
2026-07-22 RYR9CD - Jul 22, 11:10 UTCJul 22, 13:10 UTC2h 0m
2026-07-21 1NK OPO → FAO Jul 21, 21:35 UTCJul 21, 22:30 UTC55m
2026-07-21 RYR8274 - Jul 21, 19:50 UTCJul 21, 20:45 UTC55m
2026-07-21 RYR81SU - Jul 21, 16:35 UTCJul 21, 19:00 UTC2h 25m
2026-07-21 RYR22EY FAO → LTN Jul 21, 13:00 UTCJul 21, 15:20 UTC2h 20m
2026-07-21 RYR1WB NDR → CRL Jul 21, 08:45 UTCJul 21, 11:20 UTC2h 35m
2026-07-21 RYR39QA FAO → NRN Jul 21, 05:25 UTCJul 21, 08:00 UTC2h 35m
2026-07-20 RYR9CD NWI → FAO Jul 20, 18:00 UTCJul 20, 20:30 UTC2h 30m
2026-07-20 RYR952H FAO → NWI Jul 20, 14:40 UTCJul 20, 17:10 UTC2h 30m
2026-07-20 RYR5A CPH → BUD Jul 20, 10:55 UTCJul 20, 13:45 UTC2h 50m
2026-07-20 RYR3JU EMA → LIG Jul 20, 07:25 UTCJul 20, 09:55 UTC2h 30m
2026-07-20 RYR6246 - Jul 20, 04:45 UTCJul 20, 05:20 UTC35m
2026-07-19 RYR52NP - Jul 19, 20:20 UTCJul 20, 00:10 UTC3h 50m
2026-07-19 RYR81 POZ → WMI Jul 19, 18:50 UTCJul 19, 19:25 UTC35m
2026-07-19 RYR6WJ VNO → TRN Jul 19, 13:10 UTCJul 19, 17:15 UTC4h 5m
2026-07-19 RYR3VD EDI → BER Jul 19, 09:25 UTCJul 19, 12:00 UTC2h 35m
2026-07-19 RYR63PR FAO → MAN Jul 19, 05:55 UTCJul 19, 08:25 UTC2h 30m
2026-07-18 RYR96CQ - Jul 18, 18:40 UTCJul 18, 21:15 UTC2h 35m
2026-07-18 RYR9452 DUB → TSF Jul 18, 15:20 UTCJul 18, 17:55 UTC2h 35m
2026-07-18 RYR322N OPO → FAO Jul 18, 13:35 UTCJul 18, 14:30 UTC55m
2026-07-18 RYR17JX FAO → OPO Jul 18, 12:05 UTCJul 18, 12:45 UTC40m
2026-07-18 RYR54LC ORK → FAO Jul 18, 08:35 UTCJul 18, 10:55 UTC2h 20m
2026-07-18 RYR8DY FAO → ORK Jul 18, 05:25 UTCJul 18, 07:30 UTC2h 5m
2026-07-17 RYR9459 - Jul 17, 21:25 UTCJul 17, 22:20 UTC55m
2026-07-17 RYR9458 - Jul 17, 19:40 UTCJul 17, 20:29 UTC50m
2026-07-17 RYR95KE - Jul 17, 16:29 UTCJul 17, 18:50 UTC2h 20m
2026-07-17 RYR57HT - Jul 17, 13:29 UTCJul 17, 15:29 UTC2h 0m
2026-07-17 RYR893Y NQY → FAO Jul 17, 09:25 UTCJul 17, 11:30 UTC2h 5m
2026-07-17 RYR96FD FAO → NQY Jul 17, 06:29 UTCJul 17, 08:25 UTC1h 55m
2026-07-16 RYR52NP - Jul 16, 18:19 UTCJul 16, 22:19 UTC4h 0m
2026-07-16 RYR6WJ VNO → TRN Jul 16, 13:54 UTCJul 16, 17:30 UTC3h 35m
2026-07-16 RYR53AX - Jul 16, 10:04 UTCJul 16, 12:25 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?
Yes. Mode-S 4D21F2 is currently airborne.
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 RYR6WJ, RYR6AX, RYR52NP, RYR11FB, RYR99TR.