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sensors Mode-S transponder

A21C4C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N235NN · EMBRAER ERJ-170-200 (long wing) · operated by AMERICAN AIRLINES INC

Hex
A21C4C
Octal
50416114
Decimal
10,624,076
Country
US
Tail
N235NN
Type
E75L
No current signal · last broadcast Jul 26, 22:25 UTC
Flights observed
725
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:25 UTC

Last known position

Most recent position reported by Mode-S A21C4C.

Country allocation

The ICAO 24-bit address A21C4C falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States 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
ENY3609 - 9 2026-07-17
ENY3939 - 8 2026-06-22
ENY3560 Envoy Air 8 2026-05-29
ENY3484 - 8 2026-06-27
ENY3415 Envoy Air 8 2026-04-26
ENY3368 - 8 2026-06-23
ENY4236 Envoy Air 7 2026-04-26
ENY4010 - 7 2026-06-29
ENY3569 - 7 2026-06-18
ENY3562 - 7 2026-07-10
ENY3509 Envoy Air 7 2026-04-26
ENY4177 - 6 2026-07-13
ENY3563 Envoy Air 6 2026-06-02
ENY3429 Envoy Air 6 2026-07-25
ENY4289 - 5 2026-04-16
ENY4235 Envoy Air 5 2026-04-27
ENY4137 - 5 2026-06-27
ENY4021 - 5 2026-07-04
ENY3997 - 5 2026-07-07
ENY3908 Envoy Air 5 2026-05-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ENY3777 MCI → DFW Jul 26, 21:35 UTCJul 26, 22:20 UTC45m
2026-07-26 ENY3777 MCI → DFW Jul 26, 20:05 UTCJul 26, 20:45 UTC40m
2026-07-26 ENY3399 SDF → DFW Jul 26, 16:40 UTCJul 26, 18:30 UTC1h 50m
2026-07-26 ENY3399 SDF → DFW Jul 26, 13:35 UTCJul 26, 15:25 UTC1h 50m
2026-07-26 ENY3830 PIT → ORD Jul 26, 01:45 UTCJul 26, 02:30 UTC45m
2026-07-25 ENY3830 PIT → ORD Jul 25, 23:55 UTCJul 26, 00:45 UTC50m
2026-07-25 ENY3429 AUS → ORD Jul 25, 19:45 UTCJul 25, 22:05 UTC2h 20m
2026-07-25 ENY3429 AUS → ORD Jul 25, 16:10 UTCJul 25, 18:30 UTC2h 20m
2026-07-25 ENY3941 CVG → ORD Jul 25, 13:15 UTCJul 25, 14:20 UTC1h 5m
2026-07-25 ENY3941 CVG → ORD Jul 25, 13:14 UTCJul 25, 14:14 UTC1h 0m
2026-07-25 ENY3903 ORD → MSN Jul 25, 02:05 UTCJul 25, 03:00 UTC55m
2026-07-24 ENY3502 MSO → DFW Jul 24, 22:55 UTCJul 25, 00:35 UTC1h 40m
2026-07-24 ENY3502 MSO → DFW Jul 24, 19:45 UTCJul 24, 21:15 UTC1h 30m
2026-07-24 ENY3478 AMA → DFW Jul 24, 17:00 UTCJul 24, 18:05 UTC1h 5m
2026-07-24 ENY3478 AMA → DFW Jul 24, 14:35 UTCJul 24, 15:35 UTC1h 0m
2026-07-24 ENY3521 ORD → SDF Jul 24, 11:25 UTCJul 24, 13:20 UTC1h 55m
2026-07-24 ENY4208 DFW → GJT Jul 24, 02:30 UTCJul 24, 04:35 UTC2h 5m
2026-07-24 ENY3803 DFW → MSY Jul 24, 00:05 UTCJul 24, 01:05 UTC1h 0m
2026-07-24 ENY3803 DFW → MSY Jul 24, 00:02 UTCJul 24, 00:57 UTC55m
2026-07-23 ENY3803 DFW → MSY Jul 23, 21:55 UTCJul 23, 22:50 UTC55m
2026-07-23 ENY3967 DFW → DGO Jul 23, 19:25 UTCJul 23, 20:30 UTC1h 5m
2026-07-23 ENY3967 DFW → DGO Jul 23, 17:40 UTCJul 23, 18:40 UTC1h 0m
2026-07-23 ENY3968 MSY → DFW Jul 23, 15:50 UTCJul 23, 16:35 UTC45m
2026-07-23 ENY3968 MSY → DFW Jul 23, 15:43 UTCJul 23, 16:29 UTC46m
2026-07-23 ENY3968 MSY → DFW Jul 23, 14:05 UTCJul 23, 14:45 UTC40m
2026-07-23 ENY3886 CLT → CVG Jul 23, 10:40 UTCJul 23, 12:40 UTC2h 0m
2026-07-23 ENY3886 CLT → CVG Jul 23, 10:35 UTCJul 23, 12:34 UTC1h 59m
2026-07-23 ENY3876 EIS → MIA Jul 23, 03:00 UTCJul 23, 03:50 UTC50m
2026-07-23 ENY3743 ABQ → AUS Jul 23, 00:25 UTCJul 23, 01:50 UTC1h 25m
2026-07-22 ENY3743 ABQ → AUS Jul 22, 22:05 UTCJul 22, 23:25 UTC1h 20m
2026-07-22 ENY3820 - Jul 22, 12:50 UTCJul 22, 13:50 UTC1h 0m
2026-07-22 ENY3820 - Jul 22, 11:10 UTCJul 22, 11:55 UTC45m
2026-07-21 ENY3487 - Jul 21, 22:40 UTCJul 22, 01:10 UTC2h 30m
2026-07-21 ENY3950 ORD → CVG Jul 21, 20:40 UTCJul 21, 21:20 UTC40m
2026-07-21 ENY3961 - Jul 21, 18:30 UTCJul 21, 19:25 UTC55m
2026-07-21 ENY4163 - Jul 21, 15:10 UTCJul 21, 17:35 UTC2h 25m
2026-07-21 ENY4163 MIA → CMH Jul 21, 15:07 UTCJul 21, 17:33 UTC2h 26m
2026-07-21 ENY3367 FAY → DFW Jul 21, 11:05 UTCJul 21, 13:30 UTC2h 25m
2026-07-21 ENY3367 FAY → DFW Jul 21, 11:02 UTCJul 21, 13:29 UTC2h 27m
2026-07-21 ENY3380 DCA → MSY Jul 21, 01:40 UTCJul 21, 04:15 UTC2h 35m
2026-07-20 ENY9865 ORD → TYS Jul 20, 22:45 UTCJul 20, 23:30 UTC45m
2026-07-17 ENY3518 - Jul 17, 16:24 UTCJul 17, 17:35 UTC1h 10m
2026-07-17 ENY3609 - Jul 17, 14:15 UTCJul 17, 15:10 UTC55m
2026-07-17 ENY3609 JAX → MIA Jul 17, 14:14 UTCJul 17, 15:07 UTC53m
2026-07-17 ENY3609 - Jul 17, 12:35 UTCJul 17, 13:25 UTC50m
2026-07-17 ENY3858 TLH → MIA Jul 17, 10:10 UTCJul 17, 11:25 UTC1h 15m
2026-07-17 ENY3585 - Jul 17, 02:39 UTCJul 17, 03:39 UTC1h 0m
2026-07-16 ENY4082 - Jul 16, 23:49 UTCJul 17, 01:35 UTC1h 45m
2026-07-16 ENY3931 CHS → ORD Jul 16, 21:00 UTCJul 16, 22:40 UTC1h 40m
2026-07-16 ENY3931 CHS → ORD Jul 16, 20:58 UTCJul 16, 22:39 UTC1h 41m

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 N235NN page for operator, model, and routing details .

Mode-S A21C4C frequently asked

What is Mode-S code A21C4C?
A21C4C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N235NN.
Where is Mode-S A21C4C registered?
Mode-S code A21C4C is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is A21C4C broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 22:25 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A21C4C, octal 50416114, decimal 10,624,076.
What flights does A21C4C operate?
Mode-S A21C4C has broadcast 20 distinct callsigns, including ENY3609, ENY3939, ENY3560, ENY3484, ENY3415.