sensors Mode-S transponder

4D21EC

ICAO 24-bit transponder address · allocated to Malta

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

Hex
4D21EC
Octal
23220754
Decimal
5,054,956
Country
MT
Tail
9H-QAD
Type
B738
Broadcasting now · callsign RYR423B · 20,775 ft
Flights observed
308
Distinct callsigns
20
Country
MT
Last broadcast
59m ago

Current position

4D21EC is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 4D21EC 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
RYR8336 Ryanair 16 2026-05-30
RYR12RM Ryanair 16 2026-05-30
RYR423B Ryanair 11 2026-05-25
RYR1WX Ryanair 11 2026-05-25
RYR957B Ryanair 9 2026-05-29
RYR49CP - 9 2026-05-29
RYR9489 Ryanair 8 2026-05-29
RYR882R - 8 2026-05-29
RYR78YM Ryanair 7 2026-05-29
RYR35MU Ryanair 7 2026-05-29
RYR88SE Ryanair 6 2026-05-28
RYR5411 Ryanair 6 2026-05-28
RYR8593 Ryanair 5 2026-05-26
RYR8592 Ryanair 5 2026-05-26
RYR4MD Ryanair 4 2026-04-29
RYR33BL Ryanair 4 2026-04-29
RYR99FP Ryanair 3 2026-05-01
RYR8603 Ryanair 3 2026-05-25
RYR8602 Ryanair 3 2026-05-25
RYR8599 Ryanair 3 2026-05-28

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 RYR8336 STN → CGN May 30, 06:55 UTCMay 30, 08:20 UTC1h 25m
2026-05-30 RYR12RM SVQ → MRS May 30, 04:40 UTCMay 30, 06:05 UTC1h 25m
2026-05-29 RYR882R - May 29, 20:40 UTCMay 29, 22:00 UTC1h 20m
2026-05-29 RYR957B LIG → STN May 29, 18:20 UTCMay 29, 19:30 UTC1h 10m
2026-05-29 RYR49CP MXP → REG May 29, 16:05 UTCMay 29, 17:35 UTC1h 30m
2026-05-29 RYR9489 EMA → PMI May 29, 13:35 UTCMay 29, 15:05 UTC1h 30m
2026-05-29 RYR35MU PSA → REG May 29, 11:40 UTCMay 29, 12:45 UTC1h 5m
2026-05-29 RYR78YM REG → PSA May 29, 09:15 UTCMay 29, 10:25 UTC1h 10m
2026-05-29 RYR8336 STN → CGN May 29, 06:40 UTCMay 29, 08:05 UTC1h 25m
2026-05-29 RYR12RM SVQ → MRS May 29, 04:10 UTCMay 29, 05:35 UTC1h 25m
2026-05-28 RYR5411 STN → REG May 28, 19:15 UTCMay 28, 21:45 UTC2h 30m
2026-05-28 RYR88SE REG → STN May 28, 15:25 UTCMay 28, 18:15 UTC2h 50m
2026-05-28 RYR8336 STN → CGN May 28, 12:40 UTCMay 28, 14:10 UTC1h 30m
2026-05-28 RYR12RM SVQ → MRS May 28, 10:05 UTCMay 28, 11:40 UTC1h 35m
2026-05-28 RYR8598 BCN → REG May 28, 07:45 UTCMay 28, 09:25 UTC1h 40m
2026-05-28 RYR8599 REG → BCN May 28, 04:35 UTCMay 28, 06:20 UTC1h 45m
2026-05-27 RYR9659 MXP → REG May 27, 18:45 UTCMay 27, 20:15 UTC1h 30m
2026-05-27 RYR9658 REG → MXP May 27, 15:25 UTCMay 27, 16:55 UTC1h 30m
2026-05-27 RYR8526 BER → STN May 27, 12:05 UTCMay 27, 14:20 UTC2h 15m
2026-05-27 RYR8527 STN → HAM May 27, 08:55 UTCMay 27, 11:20 UTC2h 25m
2026-05-27 RYR35MU PSA → REG May 27, 06:55 UTCMay 27, 08:05 UTC1h 10m
2026-05-27 RYR78YM REG → PSA May 27, 04:49 UTCMay 27, 05:55 UTC1h 5m
2026-05-26 RYR8336 STN → CGN May 26, 19:50 UTCMay 26, 21:20 UTC1h 30m
2026-05-26 RYR12RM SVQ → MRS May 26, 17:30 UTCMay 26, 18:55 UTC1h 25m
2026-05-26 RYR35MU PSA → REG May 26, 15:29 UTCMay 26, 16:45 UTC1h 15m
2026-05-26 RYR78YM REG → PSA May 26, 13:29 UTCMay 26, 14:35 UTC1h 5m
2026-05-26 RYR8592 BLQ → REG May 26, 11:05 UTCMay 26, 12:20 UTC1h 15m
2026-05-26 RYR8593 REG → BLQ May 26, 09:04 UTCMay 26, 10:20 UTC1h 15m
2026-05-26 RYR49CP MXP → REG May 26, 06:49 UTCMay 26, 08:19 UTC1h 30m
2026-05-26 RYR9489 EMA → PMI May 26, 04:20 UTCMay 26, 05:45 UTC1h 25m
2026-05-25 RYR882R - May 25, 18:05 UTCMay 25, 19:25 UTC1h 19m
2026-05-25 RYR957B LIG → STN May 25, 15:55 UTCMay 25, 17:10 UTC1h 15m
2026-05-25 RYR1WX PSA → BUD May 25, 13:10 UTCMay 25, 14:45 UTC1h 35m
2026-05-25 RYR423B REG → TRN May 25, 10:40 UTCMay 25, 12:05 UTC1h 25m
2026-05-25 RYR8602 STN → LUX May 25, 07:25 UTCMay 25, 09:30 UTC2h 5m
2026-05-25 RYR8603 NRN → VLC May 25, 04:20 UTCMay 25, 06:35 UTC2h 15m
2026-05-24 RYR8336 STN → CGN May 24, 19:10 UTCMay 24, 20:30 UTC1h 20m
2026-05-24 RYR12RM SVQ → MRS May 24, 16:25 UTCMay 24, 17:55 UTC1h 30m
2026-05-24 RYR1WX PSA → BUD May 24, 14:00 UTCMay 24, 15:25 UTC1h 25m
2026-05-24 RYR423B REG → TRN May 24, 11:40 UTCMay 24, 13:05 UTC1h 25m
2026-05-24 RYR5411 STN → REG May 24, 07:55 UTCMay 24, 10:30 UTC2h 35m
2026-05-24 RYR88SE REG → STN May 24, 04:10 UTCMay 24, 06:55 UTC2h 45m
2026-05-23 RYR275C BVA → REG May 23, 18:25 UTCMay 23, 20:35 UTC2h 10m
2026-05-23 RYR4521 MAN → CIA May 23, 14:55 UTCMay 23, 17:15 UTC2h 20m
2026-05-23 RYR1WX PSA → BUD May 23, 11:25 UTCMay 23, 12:55 UTC1h 30m
2026-05-23 RYR423B REG → TRN May 23, 09:05 UTCMay 23, 10:35 UTC1h 30m
2026-05-23 RYR8336 STN → CGN May 23, 06:50 UTCMay 23, 08:15 UTC1h 25m
2026-05-23 RYR12RM SVQ → MRS May 23, 04:25 UTCMay 23, 06:00 UTC1h 35m
2026-05-22 RYR882R - May 22, 21:05 UTCMay 22, 22:15 UTC1h 10m
2026-05-22 RYR957B LIG → STN May 22, 18:35 UTCMay 22, 19:50 UTC1h 15m

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

Mode-S 4D21EC frequently asked

What is Mode-S code 4D21EC?
4D21EC is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-QAD.
Where is Mode-S 4D21EC registered?
Mode-S code 4D21EC is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D21EC broadcasting right now?
Yes. Mode-S 4D21EC is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D21EC, octal 23220754, decimal 5,054,956.
What flights does 4D21EC operate?
Mode-S 4D21EC has broadcast 20 distinct callsigns, including RYR8336, RYR12RM, RYR423B, RYR1WX, RYR957B.