sensors Mode-S transponder

4D21E9

ICAO 24-bit transponder address · allocated to Malta

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

Hex
4D21E9
Octal
23220751
Decimal
5,054,953
Country
MT
Tail
9H-QAA
Type
B738
No current signal · last broadcast 20m ago
Flights observed
313
Distinct callsigns
20
Country
MT
Last broadcast
20m ago

Last known position

Most recent position reported by Mode-S 4D21E9.

Country allocation

The ICAO 24-bit address 4D21E9 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
RYR738U Ryanair 4 2026-05-27
RYR6FR Ryanair 4 2026-05-27
RYR85AX Ryanair 3 2026-05-22
RYR80PC Ryanair 3 2026-05-24
RYR62BC Ryanair 3 2026-05-22
RYR5YX - 3 2026-04-13
RYR5914 Ryanair 3 2026-05-24
RYR4W Ryanair 3 2026-04-14
RYR348J Ryanair 3 2026-05-05
RYR9JQ Ryanair 2 2026-05-18
RYR97SR Ryanair 2 2026-05-21
RYR96RB Ryanair 2 2026-05-26
RYR8QW Ryanair 2 2026-05-23
RYR84JW Ryanair 2 2026-05-20
RYR8334 - 2 2026-04-13
RYR7YG Ryanair 2 2026-05-04
RYR7PC - 2 2026-04-14
RYR73KY Ryanair 2 2026-05-12
RYR70FA Ryanair 2 2026-05-20
RYR6K Ryanair 2 2026-05-06

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 RYR2PR FAO → LUX May 30, 19:50 UTCMay 30, 20:15 UTC25m
2026-05-30 RYR7KQ WMI → AGP May 30, 16:30 UTCMay 30, 18:40 UTC2h 10m
2026-05-30 RYR3JR SVQ → TSF May 30, 13:25 UTCMay 30, 15:40 UTC2h 15m
2026-05-30 RYR79JP FMO → AGP May 30, 09:15 UTCMay 30, 11:50 UTC2h 35m
2026-05-30 RYR3368 AGP → FMO May 30, 05:35 UTCMay 30, 08:15 UTC2h 40m
2026-05-29 RYR42SP BRI → AGP May 29, 20:50 UTCMay 29, 23:20 UTC2h 30m
2026-05-29 RYR7CZ KIR → MAN May 29, 17:15 UTCMay 29, 19:55 UTC2h 40m
2026-05-29 RYR1TQ AGA → MAD May 29, 13:25 UTCMay 29, 15:55 UTC2h 30m
2026-05-29 RYR96GG AGP → DUB May 29, 09:25 UTCMay 29, 12:25 UTC3h 0m
2026-05-29 RYR4461 FEZ → AGP May 29, 07:35 UTCMay 29, 08:20 UTC45m
2026-05-29 RYR81NH AGP → FEZ May 29, 06:05 UTCMay 29, 06:40 UTC35m
2026-05-28 RYR70XH CPH → VIE May 28, 21:15 UTCMay 28, 23:30 UTC2h 15m
2026-05-28 RYR15DG - May 28, 18:15 UTCMay 28, 18:40 UTC25m
2026-05-28 RYR2681 NAP → PMO May 28, 16:45 UTCMay 28, 17:15 UTC30m
2026-05-28 RYR4NR AGP → SCQ May 28, 12:55 UTCMay 28, 15:30 UTC2h 35m
2026-05-28 RYR1316 NAP → LIS May 28, 07:45 UTCMay 28, 10:25 UTC2h 40m
2026-05-27 RYR7YM ARN → FKB May 27, 19:55 UTCMay 27, 20:45 UTC50m
2026-05-27 RYR56RK NAP → MXP May 27, 18:00 UTCMay 27, 19:00 UTC1h 0m
2026-05-27 RYR6FR ALC → BRS May 27, 16:15 UTCMay 27, 16:50 UTC35m
2026-05-27 RYR738U NAP → PMO May 27, 15:00 UTCMay 27, 15:30 UTC30m
2026-05-27 RYR4046 KRK → NAP May 27, 07:00 UTCMay 27, 08:20 UTC1h 20m
2026-05-27 RYR7TU BVA → DUB May 27, 04:34 UTCMay 27, 06:09 UTC1h 35m
2026-05-26 RYR28RV - May 26, 18:50 UTCMay 26, 19:30 UTC40m
2026-05-26 RYR96RB NAP → VCE May 26, 17:09 UTCMay 26, 17:59 UTC50m
2026-05-26 RYR8VV STN → ACE May 26, 14:50 UTCMay 26, 16:15 UTC1h 25m
2026-05-26 RYR30AM - May 26, 12:20 UTCMay 26, 13:50 UTC1h 30m
2026-05-26 RYR53JH CPH → NAP May 26, 08:39 UTCMay 26, 11:00 UTC2h 20m
2026-05-26 RYR3DP EIN → RAK May 26, 05:25 UTCMay 26, 07:45 UTC2h 20m
2026-05-25 RYR801W MXP → NAP May 25, 19:05 UTCMay 25, 20:04 UTC1h 0m
2026-05-25 RYR5U - May 25, 17:05 UTCMay 25, 18:10 UTC1h 5m
2026-05-25 RYR653C MRS → NAP May 25, 14:45 UTCMay 25, 15:55 UTC1h 10m
2026-05-25 RYR1QM LCJ → DUB May 25, 12:35 UTCMay 25, 13:55 UTC1h 20m
2026-05-25 RYR6833 EIN → NAP May 25, 08:10 UTCMay 25, 10:10 UTC2h 0m
2026-05-25 RYR3QR BGY → VLC May 25, 05:15 UTCMay 25, 07:00 UTC1h 45m
2026-05-24 RYR1775 MLA → FKB May 24, 19:15 UTCMay 24, 20:25 UTC1h 10m
2026-05-24 RYR39AX NAP → MLA May 24, 17:05 UTCMay 24, 17:50 UTC45m
2026-05-24 RYR18WL WRO → NAP May 24, 14:30 UTCMay 24, 15:55 UTC1h 25m
2026-05-24 RYR4WZ FMM → OPO May 24, 11:55 UTCMay 24, 13:30 UTC1h 35m
2026-05-24 RYR5914 MXP → NAP May 24, 09:35 UTCMay 24, 10:45 UTC1h 10m
2026-05-24 RYR80PC NAP → MXP May 24, 06:55 UTCMay 24, 08:00 UTC1h 5m
2026-05-23 RYR1NU MRS → FAO May 23, 17:55 UTCMay 23, 20:20 UTC2h 26m
2026-05-23 RYR4ZQ NUE → BNX May 23, 14:25 UTCMay 23, 16:55 UTC2h 30m
2026-05-23 RYR8QW MME → PMI May 23, 12:20 UTCMay 23, 13:00 UTC40m
2026-05-23 RYR26NW NAP → CTA May 23, 10:50 UTCMay 23, 11:20 UTC30m
2026-05-23 RYR99LP BVA → NAP May 23, 07:45 UTCMay 23, 09:30 UTC1h 45m
2026-05-23 RYR94PK STN → ALC May 23, 04:45 UTCMay 23, 06:50 UTC2h 5m
2026-05-22 RYR1QK BER → TFS May 22, 18:25 UTCMay 22, 19:20 UTC55m
2026-05-22 RYR50DB NAP → VRN May 22, 16:40 UTCMay 22, 17:40 UTC1h 0m
2026-05-22 RYR62BC PRG → NAP May 22, 14:20 UTCMay 22, 15:40 UTC1h 20m
2026-05-22 RYR85AX NAP → PRG May 22, 12:10 UTCMay 22, 13:35 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-QAA page for operator, model, and routing details .

Mode-S 4D21E9 frequently asked

What is Mode-S code 4D21E9?
4D21E9 is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-QAA.
Where is Mode-S 4D21E9 registered?
Mode-S code 4D21E9 is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D21E9 broadcasting right now?
No active broadcast right now. Last signal was 20m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D21E9, octal 23220751, decimal 5,054,953.
What flights does 4D21E9 operate?
Mode-S 4D21E9 has broadcast 20 distinct callsigns, including RYR738U, RYR6FR, RYR85AX, RYR80PC, RYR62BC.