sensors Mode-S transponder

4D21F0

ICAO 24-bit transponder address · allocated to Malta

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

Hex
4D21F0
Octal
23220760
Decimal
5,054,960
Country
MT
Tail
9H-QAH
Type
B738
No current signal · last broadcast Jul 26, 20:40 UTC
Flights observed
538
Distinct callsigns
20
Country
MT
Last broadcast
Jul 26, 20:40 UTC

Last known position

Most recent position reported by Mode-S 4D21F0.

Country allocation

The ICAO 24-bit address 4D21F0 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
RYR59CJ - 10 2026-07-16
RYR1795 - 10 2026-07-16
RYR8415 - 7 2026-07-17
RYR675G - 7 2026-07-17
RYR3ZQ - 7 2026-07-17
RYR36HX Ryanair 7 2026-07-17
RYR86TK - 6 2026-06-17
RYR5CW Ryanair 6 2026-06-14
RYR30CK Ryanair 6 2026-06-29
RYR2AU - 6 2026-06-28
RYR4UU Ryanair 5 2026-04-18
RYR42CL - 5 2026-06-17
RYR36PW Ryanair 5 2026-06-29
RYR99PH Ryanair 4 2026-06-19
RYR79TR - 4 2026-07-15
RYR7868 - 4 2026-07-15
RYR6499 Ryanair 4 2026-06-19
RYR550E - 4 2026-07-15
RYR4NH - 4 2026-06-28
RYR30KM Ryanair 4 2026-06-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 RYR5AD CTA → PSA Jul 26, 19:25 UTCJul 26, 20:40 UTC1h 15m
2026-07-26 RYR28SP PSA → CTA Jul 26, 15:20 UTCJul 26, 16:25 UTC1h 5m
2026-07-26 RYR2GP AGP → EIN Jul 26, 12:55 UTCJul 26, 14:05 UTC1h 10m
2026-07-26 RYR564P PSA → BDS Jul 26, 10:40 UTCJul 26, 11:40 UTC1h 0m
2026-07-26 RYR1KD NUE → FNC Jul 26, 08:15 UTCJul 26, 09:25 UTC1h 10m
2026-07-26 RYR6204 PSA → CTA Jul 26, 05:35 UTCJul 26, 06:55 UTC1h 21m
2026-07-25 RYR5ZK MAN → DUB Jul 25, 21:00 UTCJul 25, 22:30 UTC1h 30m
2026-07-25 RYR44SX RAK → BRU Jul 25, 10:50 UTCJul 25, 18:30 UTC7h 40m
2026-07-24 RYR49HH SNN → BUD Jul 24, 20:40 UTCJul 25, 09:05 UTC12h 25m
2026-07-24 RYR40DY RAK → NRN Jul 24, 16:30 UTCJul 24, 19:45 UTC3h 15m
2026-07-24 RYR60HU EIN → RAK Jul 24, 11:45 UTCJul 24, 14:50 UTC3h 5m
2026-07-23 RYR50JL RAK → EIN Jul 23, 22:30 UTCJul 24, 10:50 UTC12h 20m
2026-07-23 RYR7RW - Jul 23, 20:40 UTCJul 23, 21:35 UTC55m
2026-07-23 RYR7TT - Jul 23, 17:45 UTCJul 23, 18:45 UTC1h 0m
2026-07-23 RYR9QJ - Jul 23, 15:05 UTCJul 23, 16:10 UTC1h 5m
2026-07-23 RYR96XU - Jul 23, 11:20 UTCJul 23, 12:50 UTC1h 30m
2026-07-23 RYR227G TRN → MAD Jul 23, 07:50 UTCJul 23, 09:30 UTC1h 40m
2026-07-23 RYR158V - Jul 23, 05:05 UTCJul 23, 07:00 UTC1h 55m
2026-07-22 RYR59YY - Jul 22, 19:00 UTCJul 22, 21:05 UTC2h 5m
2026-07-22 RYR830B MAD → LPL Jul 22, 16:05 UTCJul 22, 18:10 UTC2h 5m
2026-07-22 RYR29KK MAH → MAD Jul 22, 13:35 UTCJul 22, 14:45 UTC1h 10m
2026-07-22 RYR36GA - Jul 22, 11:35 UTCJul 22, 12:30 UTC55m
2026-07-22 RYR5NY FAO → MAN Jul 22, 04:10 UTCJul 22, 10:25 UTC6h 15m
2026-07-21 RYR6RH - Jul 21, 21:00 UTCJul 21, 22:10 UTC1h 10m
2026-07-21 RYR49WQ ESU → CRL Jul 21, 19:00 UTCJul 21, 19:55 UTC55m
2026-07-21 RYR908N BLQ → MAD Jul 21, 15:25 UTCJul 21, 17:40 UTC2h 15m
2026-07-21 RYR88NB MAD → BLQ Jul 21, 12:40 UTCJul 21, 14:25 UTC1h 45m
2026-07-21 RYR57TV - Jul 21, 08:00 UTCJul 21, 10:20 UTC2h 20m
2026-07-21 RYR5834 EDI → BGY Jul 21, 05:00 UTCJul 21, 07:05 UTC2h 5m
2026-07-20 RYR7UY BRS → DUB Jul 20, 22:55 UTCJul 20, 23:40 UTC45m
2026-07-20 RYR8AT STN → ORB Jul 20, 21:00 UTCJul 20, 22:00 UTC1h 0m
2026-07-20 RYR4VX BDS → EIN Jul 20, 17:45 UTCJul 20, 19:50 UTC2h 5m
2026-07-20 RYR49AV MAD → FCO Jul 20, 14:30 UTCJul 20, 16:20 UTC1h 50m
2026-07-20 RYR4FD BGY → MAD Jul 20, 10:50 UTCJul 20, 13:00 UTC2h 10m
2026-07-20 RYR2MP - Jul 20, 08:00 UTCJul 20, 09:35 UTC1h 35m
2026-07-20 RYR31VW - Jul 20, 06:00 UTCJul 20, 06:45 UTC45m
2026-07-20 RYR7DU BRS → GNB Jul 20, 04:10 UTCJul 20, 05:05 UTC55m
2026-07-19 RYR48YA - Jul 19, 20:30 UTCJul 19, 22:25 UTC1h 55m
2026-07-19 RYR59JH FAO → STN Jul 19, 16:25 UTCJul 19, 18:55 UTC2h 30m
2026-07-19 RYR4W - Jul 19, 13:00 UTCJul 19, 15:35 UTC2h 35m
2026-07-19 RYR1BL SUF → TRS Jul 19, 10:00 UTCJul 19, 11:45 UTC1h 45m
2026-07-19 RYR87SW - Jul 19, 07:35 UTCJul 19, 08:55 UTC1h 20m
2026-07-18 RYR80EA SNN → STN Jul 18, 22:20 UTCJul 18, 23:20 UTC1h 0m
2026-07-18 RYR576P - Jul 18, 20:30 UTCJul 18, 21:30 UTC1h 0m
2026-07-18 RYR86NE BCN → STN Jul 18, 17:45 UTCJul 18, 19:35 UTC1h 50m
2026-07-18 RYR46PL - Jul 18, 14:55 UTCJul 18, 16:40 UTC1h 45m
2026-07-18 RYR23YL - Jul 18, 12:25 UTCJul 18, 14:05 UTC1h 40m
2026-07-18 RYR834F STN → GOT Jul 18, 09:50 UTCJul 18, 11:15 UTC1h 25m
2026-07-18 RYR7NT RIX → CGN Jul 18, 07:35 UTCJul 18, 09:00 UTC1h 25m
2026-07-18 RYR51KK - Jul 18, 05:10 UTCJul 18, 06:25 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-QAH page for operator, model, and routing details .

Mode-S 4D21F0 frequently asked

What is Mode-S code 4D21F0?
4D21F0 is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-QAH.
Where is Mode-S 4D21F0 registered?
Mode-S code 4D21F0 is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D21F0 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 20:40 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D21F0, octal 23220760, decimal 5,054,960.
What flights does 4D21F0 operate?
Mode-S 4D21F0 has broadcast 20 distinct callsigns, including RYR59CJ, RYR1795, RYR8415, RYR675G, RYR3ZQ.