sensors Mode-S transponder

4D2251

ICAO 24-bit transponder address · allocated to Malta

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

Hex
4D2251
Octal
23221121
Decimal
5,055,057
Country
MT
Tail
9H-QCK
Type
B738
No current signal · last broadcast 1h ago
Flights observed
300
Distinct callsigns
20
Country
MT
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S 4D2251.

Country allocation

The ICAO 24-bit address 4D2251 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
RYR49EJ Ryanair 4 2026-04-16
RYR5ZK - 3 2026-04-14
RYR5WW Ryanair 3 2026-05-13
RYR1LC Ryanair 3 2026-05-13
RYR9341 - 2 2026-04-16
RYR90QC Ryanair 2 2026-05-25
RYR8RB Ryanair 2 2026-04-15
RYR8CV - 2 2026-04-15
RYR83AU Ryanair 2 2026-04-17
RYR7SH Ryanair 2 2026-05-08
RYR7B Ryanair 2 2026-04-30
RYR75WK Ryanair 2 2026-05-17
RYR71JV Ryanair 2 2026-05-30
RYR70CB Ryanair 2 2026-05-25
RYR6LW - 2 2026-04-16
RYR6CU Ryanair 2 2026-05-26
RYR66DT Ryanair 2 2026-04-17
RYR61VB Ryanair 2 2026-05-20
RYR61NG Ryanair 2 2026-05-04
RYR5ZC Ryanair 2 2026-05-30

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 RYR96WH - May 30, 14:55 UTCMay 30, 16:15 UTC1h 20m
2026-05-30 RYR5ZC PSA → PIK May 30, 11:20 UTCMay 30, 13:35 UTC2h 15m
2026-05-30 RYR71JV MAN → PMI May 30, 07:35 UTCMay 30, 09:45 UTC2h 10m
2026-05-29 RYR3737 ORK → BHX May 29, 07:15 UTCMay 29, 09:00 UTC1h 45m
2026-05-28 RYR99AP MAN → CCF May 28, 14:00 UTCMay 28, 15:40 UTC1h 40m
2026-05-28 RYR88FE RMU → MAN May 28, 09:30 UTCMay 28, 12:00 UTC2h 30m
2026-05-28 RYR99RH MAD → CTA May 28, 05:55 UTCMay 28, 08:15 UTC2h 20m
2026-05-27 RYR2QB ARN → STN May 27, 19:50 UTCMay 27, 20:40 UTC50m
2026-05-27 RYR92LR MAN → BVA May 27, 18:10 UTCMay 27, 19:00 UTC50m
2026-05-27 RYR86UV - May 27, 14:50 UTCMay 27, 17:10 UTC2h 20m
2026-05-27 RYR3MG VLC → FMM May 27, 11:50 UTCMay 27, 13:50 UTC2h 0m
2026-05-27 RYR1NN CTA → TRN May 27, 08:20 UTCMay 27, 10:40 UTC2h 20m
2026-05-27 RYR9QX NCL → LPA May 27, 05:04 UTCMay 27, 07:20 UTC2h 16m
2026-05-26 RYR90FP KRK → MAN May 26, 21:20 UTCMay 26, 23:39 UTC2h 20m
2026-05-26 RYR31CC MAN → KRK May 26, 18:24 UTCMay 26, 20:24 UTC2h 0m
2026-05-26 RYR390A EIN → MAN May 26, 16:15 UTCMay 26, 17:25 UTC1h 10m
2026-05-26 RYR6CU FCO → PMI May 26, 14:24 UTCMay 26, 15:24 UTC1h 0m
2026-05-26 RYR6AR STN → KGS May 26, 11:09 UTCMay 26, 13:29 UTC2h 20m
2026-05-26 RYR6RP DUB → GOT May 26, 07:40 UTCMay 26, 09:59 UTC2h 20m
2026-05-25 RYR7261 BRI → MAD May 25, 20:34 UTCMay 25, 23:04 UTC2h 30m
2026-05-25 RYR60ZJ MAN → AGP May 25, 17:05 UTCMay 25, 19:35 UTC2h 29m
2026-05-25 RYR5ZC PSA → PIK May 25, 13:35 UTCMay 25, 15:45 UTC2h 10m
2026-05-25 RYR71JV MAN → PMI May 25, 09:50 UTCMay 25, 12:00 UTC2h 10m
2026-05-25 RYR90QC DUB → PFO May 25, 07:45 UTCMay 25, 08:45 UTC1h 0m
2026-05-25 RYR70CB GRO → EIN May 25, 05:55 UTCMay 25, 06:55 UTC1h 0m
2026-05-24 RYR91XZ ALC → STN May 24, 17:35 UTCMay 24, 20:10 UTC2h 35m
2026-05-24 RYR163D TRN → SVQ May 24, 13:55 UTCMay 24, 16:15 UTC2h 20m
2026-05-24 RYR55RY CPH → MAN May 24, 11:20 UTCMay 24, 12:45 UTC1h 25m
2026-05-24 RYR2KZ AGP → BFS May 24, 08:40 UTCMay 24, 10:00 UTC1h 20m
2026-05-24 RYR90QC DUB → PFO May 24, 06:45 UTCMay 24, 07:40 UTC55m
2026-05-24 RYR70CB GRO → EIN May 24, 04:55 UTCMay 24, 05:55 UTC1h 0m
2026-05-23 RYR6968 CPH → MAN May 23, 20:45 UTCMay 23, 22:15 UTC1h 30m
2026-05-23 RYR10MA TRN → DUB May 23, 18:25 UTCMay 23, 19:50 UTC1h 25m
2026-05-23 RYR41VQ VCE → MAN May 23, 15:15 UTCMay 23, 17:15 UTC2h 0m
2026-05-23 RYR73EJ MAN → VCE May 23, 12:20 UTCMay 23, 14:15 UTC1h 55m
2026-05-23 RYR3CE NAP → TLS May 23, 09:00 UTCMay 23, 11:05 UTC2h 5m
2026-05-23 RYR39TP MAN → OPO May 23, 05:50 UTCMay 23, 07:50 UTC2h 0m
2026-05-22 RYR63PR CRL → BLQ May 22, 19:50 UTCMay 22, 22:15 UTC2h 25m
2026-05-22 RYR3VD EDI → BER May 22, 15:15 UTCMay 22, 17:55 UTC2h 40m
2026-05-22 RYR390A EIN → MAN May 22, 12:55 UTCMay 22, 13:55 UTC1h 0m
2026-05-22 RYR6CU FCO → PMI May 22, 11:00 UTCMay 22, 11:55 UTC55m
2026-05-22 RYR56VX - May 22, 09:15 UTCMay 22, 10:00 UTC45m
2026-05-22 RYR3TX SOF → EIN May 22, 07:35 UTCMay 22, 08:20 UTC45m
2026-05-21 RYR21WJ DUB → MAN May 21, 21:20 UTCMay 21, 21:50 UTC30m
2026-05-21 RYR3AC WMI → BGY May 21, 19:05 UTCMay 21, 20:25 UTC1h 20m
2026-05-21 RYR40VL DUB → AMS May 21, 17:00 UTCMay 21, 18:05 UTC1h 5m
2026-05-21 RYR40ND BVA → DUB May 21, 14:20 UTCMay 21, 15:30 UTC1h 10m
2026-05-21 RYR50DA DUB → BVA May 21, 12:30 UTCMay 21, 13:30 UTC1h 0m
2026-05-21 RYR7ZW RZE → LTN May 21, 10:30 UTCMay 21, 11:25 UTC55m
2026-05-21 RYR5UJ BLQ → BOD May 21, 08:20 UTCMay 21, 09:20 UTC1h 0m

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

Mode-S 4D2251 frequently asked

What is Mode-S code 4D2251?
4D2251 is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-QCK.
Where is Mode-S 4D2251 registered?
Mode-S code 4D2251 is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D2251 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D2251, octal 23221121, decimal 5,055,057.
What flights does 4D2251 operate?
Mode-S 4D2251 has broadcast 20 distinct callsigns, including RYR49EJ, RYR5ZK, RYR5WW, RYR1LC, RYR9341.