Apparatus

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sensors Mode-S transponder

A1B4AB

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N209NN · EMBRAER ERJ-170-200 (long wing) · operated by AMERICAN AIRLINES INC

Hex
A1B4AB
Octal
50332253
Decimal
10,597,547
Country
US
Tail
N209NN
Type
E75L
No current signal · last broadcast Jul 26, 22:45 UTC
Flights observed
453
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:45 UTC

Last known position

Most recent position reported by Mode-S A1B4AB.

Country allocation

The ICAO 24-bit address A1B4AB 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
ENY3464 Envoy Air 7 2026-07-21
ENY3516 Envoy Air 6 2026-07-22
ENY3469 Envoy Air 6 2026-07-23
ENY4188 - 5 2026-07-08
ENY4157 Envoy Air 5 2026-05-02
ENY4007 Envoy Air 5 2026-05-17
ENY3794 - 5 2026-07-04
ENY3729 Envoy Air 5 2026-07-25
ENY3701 - 5 2026-07-15
ENY4230 Envoy Air 4 2026-04-14
ENY4162 Envoy Air 4 2026-04-16
ENY4064 - 4 2026-07-01
ENY4061 - 4 2026-07-10
ENY3924 - 4 2026-07-15
ENY3879 - 4 2026-07-20
ENY3862 Envoy Air 4 2026-04-13
ENY3673 - 4 2026-07-08
ENY3603 - 4 2026-07-05
ENY3503 Envoy Air 4 2026-07-07
ENY3426 - 4 2026-07-16

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ENY4087 CLT → XNA Jul 26, 22:25 UTCJul 26, 22:45 UTC20m
2026-07-26 ENY3562 CWA → ORD Jul 26, 18:55 UTCJul 26, 19:35 UTC40m
2026-07-26 ENY3562 CWA → ORD Jul 26, 17:15 UTCJul 26, 17:50 UTC35m
2026-07-26 ENY3871 BOS → ORD Jul 26, 14:05 UTCJul 26, 16:05 UTC2h 0m
2026-07-26 ENY3871 BOS → ORD Jul 26, 14:02 UTCJul 26, 15:51 UTC1h 49m
2026-07-26 ENY3693 DFW → XNA Jul 26, 03:40 UTCJul 26, 04:30 UTC50m
2026-07-26 ENY3787 IND → DCA Jul 26, 01:10 UTCJul 26, 02:25 UTC1h 15m
2026-07-25 ENY3787 IND → DCA Jul 25, 23:05 UTCJul 26, 00:00 UTC55m
2026-07-25 ENY3999 DTW → DCA Jul 25, 20:35 UTCJul 25, 21:25 UTC50m
2026-07-25 ENY3999 DTW → DCA Jul 25, 18:30 UTCJul 25, 19:15 UTC45m
2026-07-25 ENY3576 ORD → FAR Jul 25, 15:55 UTCJul 25, 17:05 UTC1h 10m
2026-07-25 ENY3576 ORD → FAR Jul 25, 14:00 UTCJul 25, 15:00 UTC1h 0m
2026-07-25 ENY3930 GRR → MIA Jul 25, 11:10 UTCJul 25, 12:05 UTC55m
2026-07-25 ENY3900 EWR → ORD Jul 25, 02:50 UTCJul 25, 03:30 UTC40m
2026-07-25 ENY3729 CMH → MIA Jul 25, 01:15 UTCJul 25, 01:50 UTC35m
2026-07-25 ENY3729 CMH → MIA Jul 25, 01:14 UTCJul 25, 01:48 UTC34m
2026-07-24 ENY3729 CMH → MIA Jul 24, 23:55 UTCJul 25, 00:35 UTC40m
2026-07-24 ENY3676 MIA → CVG Jul 24, 21:50 UTCJul 24, 22:55 UTC1h 5m
2026-07-24 ENY3676 MIA → CVG Jul 24, 21:44 UTCJul 24, 22:47 UTC1h 3m
2026-07-24 ENY3676 MIA → CVG Jul 24, 17:55 UTCJul 24, 19:20 UTC1h 25m
2026-07-24 ENY3486 AZO → ORD Jul 24, 15:25 UTCJul 24, 16:25 UTC1h 0m
2026-07-24 ENY3486 AZO → ORD Jul 24, 13:35 UTCJul 24, 14:30 UTC55m
2026-07-24 ENY3601 GRR → MIA Jul 24, 11:10 UTCJul 24, 11:40 UTC30m
2026-07-24 ENY3601 GRR → MIA Jul 24, 11:06 UTCJul 24, 11:39 UTC33m
2026-07-24 ENY3666 JAX → ORD Jul 24, 03:55 UTCJul 24, 04:20 UTC25m
2026-07-24 ENY3657 FWA → DFW Jul 24, 01:40 UTCJul 24, 02:40 UTC1h 0m
2026-07-23 ENY3657 FWA → DFW Jul 23, 23:50 UTCJul 24, 00:30 UTC40m
2026-07-23 ENY3593 DCA → BOS Jul 23, 22:00 UTCJul 23, 22:50 UTC50m
2026-07-23 ENY3593 DCA → BOS Jul 23, 21:55 UTCJul 23, 22:46 UTC51m
2026-07-23 ENY3593 DCA → BOS Jul 23, 20:10 UTCJul 23, 21:05 UTC55m
2026-07-23 ENY3469 ORD → DSM Jul 23, 17:35 UTCJul 23, 19:10 UTC1h 35m
2026-07-23 ENY3469 ORD → DSM Jul 23, 17:34 UTCJul 23, 19:04 UTC1h 30m
2026-07-23 ENY3469 ORD → DSM Jul 23, 15:05 UTCJul 23, 16:25 UTC1h 20m
2026-07-23 ENY3867 BWI → ORD Jul 23, 12:20 UTCJul 23, 13:20 UTC1h 0m
2026-07-23 ENY3868 DCA → CVG Jul 23, 01:35 UTCJul 23, 02:20 UTC45m
2026-07-22 ENY3535 MIA → AUS Jul 22, 23:20 UTCJul 23, 00:05 UTC45m
2026-07-22 ENY3535 MIA → AUS Jul 22, 23:19 UTCJul 23, 00:01 UTC42m
2026-07-22 ENY3533 DFW → OKC Jul 22, 21:40 UTCJul 22, 22:10 UTC30m
2026-07-22 ENY3516 ORD → DSM Jul 22, 18:50 UTCJul 22, 20:00 UTC1h 10m
2026-07-22 ENY3516 ORD → DSM Jul 22, 18:44 UTCJul 22, 19:58 UTC1h 14m
2026-07-22 ENY3516 ORD → DSM Jul 22, 16:40 UTCJul 22, 17:50 UTC1h 10m
2026-07-22 ENY3737 SBP → PHX Jul 22, 14:50 UTCJul 22, 15:15 UTC25m
2026-07-22 ENY3911 CMH → DCA Jul 22, 03:05 UTCJul 22, 04:35 UTC1h 30m
2026-07-22 ENY4091 ORD → PIA Jul 22, 00:45 UTCJul 22, 02:00 UTC1h 15m
2026-07-21 ENY4091 ORD → PIA Jul 21, 21:45 UTCJul 21, 22:55 UTC1h 10m
2026-07-21 ENY3464 ORD → ALB Jul 21, 19:35 UTCJul 21, 20:35 UTC1h 0m
2026-07-21 ENY3464 ORD → ALB Jul 21, 19:34 UTCJul 21, 20:31 UTC57m
2026-07-21 ENY3464 ORD → ALB Jul 21, 17:40 UTCJul 21, 18:30 UTC50m
2026-07-21 ENY4033 XNA → PHX Jul 21, 13:35 UTCJul 21, 15:45 UTC2h 10m
2026-07-20 ENY4086 PHX → XNA Jul 20, 23:20 UTCJul 21, 01:45 UTC2h 24m

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 N209NN page for operator, model, and routing details .

Mode-S A1B4AB frequently asked

What is Mode-S code A1B4AB?
A1B4AB is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N209NN.
Where is Mode-S A1B4AB registered?
Mode-S code A1B4AB 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 A1B4AB broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 22:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1B4AB, octal 50332253, decimal 10,597,547.
What flights does A1B4AB operate?
Mode-S A1B4AB has broadcast 20 distinct callsigns, including ENY3464, ENY3516, ENY3469, ENY4188, ENY4157.