Apparatus

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sensors Mode-S transponder

A657BF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N508AY · AIRBUS A-321 · operated by AMERICAN AIRLINES INC

Hex
A657BF
Octal
51453677
Decimal
10,901,439
Country
US
Tail
N508AY
Type
A321
Transponder active on ground
Flights observed
505
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:45 UTC

Last known position

Most recent position reported by Mode-S A657BF.

Country allocation

The ICAO 24-bit address A657BF 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
AAL2529 American Airlines 7 2026-06-17
AAL1943 American Airlines 7 2026-05-08
AAL608 - 6 2026-07-12
AAL2485 - 6 2026-06-30
AAL2325 American Airlines 6 2026-05-20
AAL1012 American Airlines 6 2026-04-17
AAL420 - 5 2026-07-19
AAL2904 - 5 2026-07-08
AAL2379 American Airlines 5 2026-07-21
AAL2127 American Airlines 5 2026-07-25
AAL2041 - 5 2026-07-02
AAL783 - 4 2026-06-19
AAL617 - 4 2026-07-04
AAL3238 American Airlines 4 2026-04-22
AAL2834 American Airlines 4 2026-04-21
AAL2826 American Airlines 4 2026-05-21
AAL2746 - 4 2026-07-19
AAL1861 - 4 2026-07-12
AAL1613 American Airlines 4 2026-04-22
AAL1266 - 4 2026-07-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 AAL1031 PHX → SJC Jul 26, 21:15 UTCJul 26, 21:45 UTC30m
2026-07-26 AAL2836 JFK → LAS Jul 26, 18:30 UTCJul 26, 19:40 UTC1h 10m
2026-07-26 AAL2836 JFK → LAS Jul 26, 15:50 UTCJul 26, 17:15 UTC1h 25m
2026-07-26 AAL1002 CVG → CLT Jul 26, 12:15 UTCJul 26, 13:45 UTC1h 30m
2026-07-26 AAL1002 CVG → CLT Jul 26, 12:11 UTCJul 26, 13:46 UTC1h 35m
2026-07-26 AAL1426 PHX → BOS Jul 26, 03:00 UTCJul 26, 04:55 UTC1h 55m
2026-07-25 AAL2442 ORD → FLL Jul 25, 23:50 UTCJul 26, 01:20 UTC1h 30m
2026-07-25 AAL2442 ORD → FLL Jul 25, 23:48 UTCJul 26, 01:19 UTC1h 31m
2026-07-25 AAL2442 ORD → FLL Jul 25, 21:05 UTCJul 25, 22:30 UTC1h 25m
2026-07-25 AAL2127 LGA → DCA Jul 25, 18:20 UTCJul 25, 19:35 UTC1h 15m
2026-07-25 AAL2127 LGA → DCA Jul 25, 18:18 UTCJul 25, 19:29 UTC1h 11m
2026-07-25 AAL2127 LGA → DCA Jul 25, 16:00 UTCJul 25, 17:05 UTC1h 5m
2026-07-25 AAL2362 DFW → SAN Jul 25, 13:35 UTCJul 25, 14:15 UTC40m
2026-07-25 AAL2362 DFW → SAN Jul 25, 11:50 UTCJul 25, 12:15 UTC25m
2026-07-25 AAL349 LGA → ORD Jul 25, 09:20 UTCJul 25, 10:20 UTC1h 0m
2026-07-22 AAL1962 CLT → PIT Jul 22, 03:05 UTCJul 22, 04:05 UTC1h 0m
2026-07-22 AAL1962 CLT → PIT Jul 22, 02:59 UTCJul 22, 04:01 UTC1h 2m
2026-07-21 AAL2379 DFW → SFO Jul 21, 23:40 UTCJul 22, 00:10 UTC30m
2026-07-21 AAL2379 DFW → SFO Jul 21, 21:40 UTCJul 21, 22:15 UTC35m
2026-07-21 AAL611 FLL → PHL Jul 21, 13:55 UTCJul 21, 20:05 UTC6h 10m
2026-07-21 AAL2842 SFO → MIA Jul 21, 10:20 UTCJul 21, 11:35 UTC1h 15m
2026-07-21 AAL2842 SFO → MIA Jul 21, 10:15 UTCJul 21, 11:30 UTC1h 15m
2026-07-21 AAL2323 ORD → MIA Jul 21, 02:30 UTCJul 21, 05:15 UTC2h 45m
2026-07-20 AAL3124 - Jul 20, 20:05 UTCJul 21, 01:05 UTC4h 59m
2026-07-20 AAL399Q - Jul 20, 16:55 UTCJul 20, 17:35 UTC40m
2026-07-20 AAL1771 - Jul 20, 01:40 UTCJul 20, 03:45 UTC2h 5m
2026-07-19 AAL420 - Jul 19, 23:50 UTCJul 20, 00:20 UTC30m
2026-07-19 AAL420 DEN → DFW Jul 19, 21:36 UTCJul 19, 23:31 UTC1h 55m
2026-07-19 AAL420 - Jul 19, 21:40 UTCJul 19, 23:45 UTC2h 5m
2026-07-19 AAL420 - Jul 19, 18:35 UTCJul 19, 20:05 UTC1h 30m
2026-07-19 AAL2746 - Jul 19, 14:15 UTCJul 19, 17:00 UTC2h 45m
2026-07-19 AAL2746 LAX → DFW Jul 19, 14:12 UTCJul 19, 16:59 UTC2h 47m
2026-07-19 AAL669 - Jul 19, 03:25 UTCJul 19, 08:10 UTC4h 45m
2026-07-19 AAL669 MIA → LAX Jul 19, 03:22 UTCJul 19, 08:03 UTC4h 41m
2026-07-18 AAL3124 - Jul 18, 20:10 UTCJul 19, 00:50 UTC4h 40m
2026-07-18 AAL2827 - Jul 18, 16:00 UTCJul 18, 18:30 UTC2h 30m
2026-07-18 AAL2827 DFW → LAX Jul 18, 15:55 UTCJul 18, 18:30 UTC2h 35m
2026-07-18 AAL599 MCO → DFW Jul 18, 11:40 UTCJul 18, 13:55 UTC2h 15m
2026-07-18 AAL1783 - Jul 18, 01:00 UTCJul 18, 02:09 UTC1h 10m
2026-07-18 AAL1783 CLT → MCO Jul 18, 00:58 UTCJul 18, 02:07 UTC1h 9m
2026-07-17 AAL1085 - Jul 17, 15:40 UTCJul 17, 22:20 UTC6h 40m
2026-07-17 AAL1266 - Jul 17, 12:04 UTCJul 17, 13:35 UTC1h 30m
2026-07-17 AAL1455 - Jul 17, 01:55 UTCJul 17, 02:54 UTC1h 0m
2026-07-16 AAL2286 PDX → DFW Jul 16, 20:49 UTCJul 17, 00:14 UTC3h 25m
2026-07-16 AAL2286 - Jul 16, 16:19 UTCJul 16, 19:40 UTC3h 20m
2026-07-16 AAL2555 BOS → DFW Jul 16, 11:20 UTCJul 16, 14:35 UTC3h 15m
2026-07-16 AAL1843 - Jul 16, 03:15 UTCJul 16, 04:55 UTC1h 40m
2026-07-15 AAL2496 - Jul 15, 23:35 UTCJul 16, 01:55 UTC2h 20m
2026-07-15 AAL2496 - Jul 15, 20:05 UTCJul 15, 22:40 UTC2h 35m
2026-07-15 AAL1310 - Jul 15, 13:05 UTCJul 15, 17:40 UTC4h 35m

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 N508AY page for operator, model, and routing details .

Mode-S A657BF frequently asked

What is Mode-S code A657BF?
A657BF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N508AY.
Where is Mode-S A657BF registered?
Mode-S code A657BF 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 A657BF broadcasting right now?
Mode-S A657BF is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A657BF, octal 51453677, decimal 10,901,439.
What flights does A657BF operate?
Mode-S A657BF has broadcast 20 distinct callsigns, including AAL2529, AAL1943, AAL608, AAL2485, AAL2325.