Apparatus

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sensors Mode-S transponder

A2C1B6

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N277NN · EMBRAER ERJ-170-200 (long wing) · operated by AMERICAN AIRLINES INC

Hex
A2C1B6
Octal
50540666
Decimal
10,666,422
Country
US
Tail
N277NN
Type
E75L
Broadcasting now · callsign ENY3554 · 36,750 ft
Flights observed
771
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:10 UTC

Current position

A2C1B6 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A2C1B6 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
ENY4147 Envoy Air 9 2026-05-02
ENY3470 Envoy Air 9 2026-07-22
ENY3427 Envoy Air 8 2026-04-21
ENY4171 Envoy Air 7 2026-07-23
ENY4138 Envoy Air 6 2026-07-25
ENY4135 Envoy Air 6 2026-05-29
ENY3976 - 6 2026-07-13
ENY3781 Envoy Air 6 2026-05-17
ENY3742 - 6 2026-07-13
ENY3485 Envoy Air 6 2026-04-24
ENY3455 - 6 2026-07-17
ENY3435 - 6 2026-06-22
ENY3355 - 6 2026-06-29
ENY3338 Envoy Air 6 2026-05-27
ENY4308 Envoy Air 5 2026-06-12
ENY4106 Envoy Air 5 2026-07-22
ENY3980 - 5 2026-07-16
ENY3906 Envoy Air 5 2026-06-03
ENY3826 Envoy Air 5 2026-06-02
ENY3806 - 5 2026-06-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ENY3750 ORD → FSD Jul 26, 20:20 UTCJul 26, 21:10 UTC50m
2026-07-26 ENY3841 DFW → CHA Jul 26, 15:55 UTCJul 26, 17:55 UTC2h 0m
2026-07-26 ENY3841 DFW → CHA Jul 26, 12:45 UTCJul 26, 14:40 UTC1h 55m
2026-07-25 ENY3816 ORD → TYS Jul 25, 22:45 UTCJul 25, 23:55 UTC1h 10m
2026-07-25 ENY3816 ORD → TYS Jul 25, 20:50 UTCJul 25, 22:00 UTC1h 10m
2026-07-25 ENY4138 CHS → DCA Jul 25, 17:50 UTCJul 25, 19:10 UTC1h 20m
2026-07-25 ENY4138 CHS → DCA Jul 25, 15:20 UTCJul 25, 16:35 UTC1h 15m
2026-07-25 ENY3824 XNA → DCA Jul 25, 11:50 UTCJul 25, 13:55 UTC2h 5m
2026-07-25 ENY3452 DCA → XNA Jul 25, 00:15 UTCJul 25, 02:30 UTC2h 15m
2026-07-24 ENY3991 CLT → ATW Jul 24, 20:45 UTCJul 24, 22:05 UTC1h 20m
2026-07-24 ENY3991 CLT → ATW Jul 24, 20:45 UTCJul 24, 21:59 UTC1h 14m
2026-07-24 ENY3991 CLT → ATW Jul 24, 18:25 UTCJul 24, 19:55 UTC1h 30m
2026-07-24 ENY3997 TYS → DCA Jul 24, 15:20 UTCJul 24, 16:50 UTC1h 30m
2026-07-24 ENY3997 TYS → DCA Jul 24, 12:35 UTCJul 24, 14:05 UTC1h 30m
2026-07-24 ENY4056 DFW → OKC Jul 24, 10:40 UTCJul 24, 11:40 UTC1h 0m
2026-07-24 ENY3975 GRR → DFW Jul 24, 03:15 UTCJul 24, 04:00 UTC45m
2026-07-24 ENY4047 PHX → SLC Jul 24, 00:47 UTCJul 24, 01:56 UTC1h 9m
2026-07-24 ENY4047 PHX → SLC Jul 24, 00:50 UTCJul 24, 01:55 UTC1h 5m
2026-07-23 ENY3438 DFW → HRL Jul 23, 21:30 UTCJul 23, 23:25 UTC1h 55m
2026-07-23 ENY3438 DFW → HRL Jul 23, 18:20 UTCJul 23, 20:35 UTC2h 15m
2026-07-23 ENY4171 ORD → CVG Jul 23, 16:05 UTCJul 23, 17:25 UTC1h 20m
2026-07-23 ENY4171 ORD → CVG Jul 23, 16:04 UTCJul 23, 17:18 UTC1h 14m
2026-07-23 ENY4171 ORD → CVG Jul 23, 14:20 UTCJul 23, 15:20 UTC1h 0m
2026-07-23 ENY3807 CID → ORD Jul 23, 11:20 UTCJul 23, 13:00 UTC1h 40m
2026-07-22 ENY3408 MEM → ORD Jul 22, 22:47 UTCJul 23, 00:51 UTC2h 4m
2026-07-22 ENY3408 MEM → ORD Jul 22, 22:50 UTCJul 23, 00:55 UTC2h 5m
2026-07-22 ENY3470 MDT → ORD Jul 22, 20:25 UTCJul 22, 21:45 UTC1h 20m
2026-07-22 ENY3470 MDT → ORD Jul 22, 20:20 UTCJul 22, 21:44 UTC1h 24m
2026-07-22 ENY3470 MDT → ORD Jul 22, 17:00 UTCJul 22, 18:45 UTC1h 45m
2026-07-22 ENY4106 ORD → BOS Jul 22, 13:45 UTCJul 22, 15:30 UTC1h 45m
2026-07-22 ENY4107 - Jul 22, 11:10 UTCJul 22, 11:35 UTC25m
2026-07-22 ENY3450 SDF → BOS Jul 22, 02:30 UTCJul 22, 04:50 UTC2h 20m
2026-07-21 ENY3762 ORD → BWI Jul 21, 20:30 UTCJul 22, 01:00 UTC4h 30m
2026-07-21 ENY3794 - Jul 21, 18:00 UTCJul 21, 18:55 UTC55m
2026-07-21 ENY3794 SGF → DFW Jul 21, 17:55 UTCJul 21, 18:49 UTC54m
2026-07-21 ENY3794 - Jul 21, 16:00 UTCJul 21, 16:55 UTC55m
2026-07-21 ENY3401 STS → DFW Jul 21, 13:55 UTCJul 21, 14:35 UTC40m
2026-07-21 ENY3401 STS → DFW Jul 21, 13:52 UTCJul 21, 14:34 UTC42m
2026-07-21 ENY3401 STS → DFW Jul 21, 12:15 UTCJul 21, 12:50 UTC35m
2026-07-21 ENY3919 GRK → DFW Jul 21, 10:10 UTCJul 21, 10:45 UTC35m
2026-07-21 ENY3957 - Jul 21, 02:45 UTCJul 21, 03:10 UTC25m
2026-07-20 ENY3443 BOS → CMH Jul 20, 23:50 UTCJul 21, 01:00 UTC1h 10m
2026-07-20 ENY3443 BOS → CMH Jul 20, 21:40 UTCJul 20, 22:40 UTC1h 0m
2026-07-20 ENY4110 - Jul 20, 19:00 UTCJul 20, 19:55 UTC55m
2026-07-20 ENY4110 - Jul 20, 17:10 UTCJul 20, 18:05 UTC55m
2026-07-20 ENY3700 - Jul 20, 14:30 UTCJul 20, 15:45 UTC1h 15m
2026-07-20 ENY3700 - Jul 20, 12:30 UTCJul 20, 13:40 UTC1h 10m
2026-07-20 ENY3988 MSN → DCA Jul 20, 10:10 UTCJul 20, 10:50 UTC40m
2026-07-20 ENY4281 ORD → TUL Jul 20, 04:20 UTCJul 20, 05:45 UTC1h 25m
2026-07-20 ENY3454 - Jul 20, 00:40 UTCJul 20, 02:40 UTC2h 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 N277NN page for operator, model, and routing details .

Mode-S A2C1B6 frequently asked

What is Mode-S code A2C1B6?
A2C1B6 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N277NN.
Where is Mode-S A2C1B6 registered?
Mode-S code A2C1B6 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 A2C1B6 broadcasting right now?
Yes. Mode-S A2C1B6 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2C1B6, octal 50540666, decimal 10,666,422.
What flights does A2C1B6 operate?
Mode-S A2C1B6 has broadcast 20 distinct callsigns, including ENY4147, ENY3470, ENY3427, ENY4171, ENY4138.