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
Broadcasting now · callsign AAL2766 · 34,025 ft
Flights observed
245
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Current position

A657BF is currently broadcasting. Map zoomed to live position.

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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 AAL1475 CLE → PHL May 29, 20:55 UTCMay 29, 22:30 UTC1h 35m
2026-05-29 AAL1475 CLE → PHL May 29, 17:50 UTCMay 29, 19:20 UTC1h 30m
2026-05-29 AAL1351 IND → PHL May 29, 12:50 UTCMay 29, 15:55 UTC3h 6m
2026-05-29 AAL2513 CLT → CMH May 29, 04:55 UTCMay 29, 05:00 UTC5m
2026-05-28 AAL2513 CLT → CMH May 28, 22:15 UTCMay 29, 01:25 UTC3h 10m
2026-05-28 AAL1846 MEM → CLT May 28, 17:55 UTCMay 28, 20:05 UTC2h 10m
2026-05-28 AAL889 PHX → AUS May 28, 15:35 UTCMay 28, 16:45 UTC1h 10m
2026-05-28 AAL1266 MSY → CLT May 28, 12:20 UTCMay 28, 13:45 UTC1h 25m
2026-05-28 AAL608 PHL → MCO May 28, 03:20 UTCMay 28, 04:50 UTC1h 30m
2026-05-28 AAL608 PHL → MCO May 28, 03:14 UTCMay 28, 04:52 UTC1h 38m
2026-05-27 AAL2529 ORD → MCO May 27, 20:30 UTCMay 28, 01:20 UTC4h 50m
2026-05-27 AAL2529 ORD → MCO May 27, 20:29 UTCMay 28, 01:21 UTC4h 52m
2026-05-27 AAL2529 ORD → MCO May 27, 14:30 UTCMay 27, 19:05 UTC4h 35m
2026-05-27 AAL2751 DFW → PHL May 27, 06:49 UTCMay 27, 10:35 UTC3h 45m
2026-05-26 AAL1031 PHX → SJC May 26, 22:20 UTCMay 27, 02:24 UTC4h 5m
2026-05-26 AAL980 ATL → DFW May 26, 16:01 UTCMay 26, 19:13 UTC3h 12m
2026-05-26 AAL980 ATL → DFW May 26, 11:15 UTCMay 26, 19:15 UTC8h 0m
2026-05-26 AAL1861 AUS → PHX May 26, 00:00 UTCMay 26, 01:30 UTC1h 30m
2026-05-25 AAL1861 AUS → PHX May 25, 21:04 UTCMay 25, 22:44 UTC1h 40m
2026-05-25 AAL2836 JFK → LAS May 25, 18:15 UTCMay 25, 19:35 UTC1h 20m
2026-05-25 AAL844 CLT → AUS May 25, 01:55 UTCMay 25, 03:20 UTC1h 25m
2026-05-24 AAL2762 ORD → MBJ May 24, 18:30 UTCMay 24, 21:15 UTC2h 45m
2026-05-24 AAL2762 ORD → MBJ May 24, 14:35 UTCMay 24, 17:00 UTC2h 25m
2026-05-24 AAL2928 MTY → JFK May 24, 12:10 UTCMay 24, 12:50 UTC40m
2026-05-24 AAL972 DFW → AUS May 24, 02:50 UTCMay 24, 03:20 UTC30m
2026-05-23 AAL2041 CLT → MSP May 23, 22:20 UTCMay 24, 01:05 UTC2h 45m
2026-05-23 AAL2041 CLT → MSP May 23, 22:15 UTCMay 24, 01:02 UTC2h 47m
2026-05-23 AAL2041 CLT → MSP May 23, 18:25 UTCMay 23, 21:00 UTC2h 35m
2026-05-23 AAL2746 MSY → PHL May 23, 14:10 UTCMay 23, 16:50 UTC2h 40m
2026-05-22 AAL2055 SFO → MIA May 22, 23:30 UTCMay 23, 03:55 UTC4h 24m
2026-05-22 AAL1179 ORD → SNA May 22, 14:05 UTCMay 22, 21:15 UTC7h 10m
2026-05-22 AAL1063 PHL → DEN May 22, 10:45 UTCMay 22, 11:35 UTC50m
2026-05-22 AAL1063 PHL → DEN May 22, 10:39 UTCMay 22, 11:27 UTC48m
2026-05-22 AAL993 CVG → CLT May 22, 02:20 UTCMay 22, 03:20 UTC1h 0m
2026-05-22 AAL993 CVG → CLT May 22, 02:15 UTCMay 22, 03:02 UTC47m
2026-05-21 AAL1067 DEN → DFW May 21, 20:15 UTCMay 22, 00:05 UTC3h 50m
2026-05-21 AAL1067 DEN → DFW May 21, 19:20 UTCMay 21, 23:54 UTC4h 34m
2026-05-21 AAL823 UVF → CLT May 21, 14:00 UTCMay 21, 17:05 UTC3h 5m
2026-05-21 AAL823 UVF → CLT May 21, 13:56 UTCMay 21, 17:51 UTC3h 55m
2026-05-21 AAL2760 DCA → MIA May 21, 11:10 UTCMay 21, 11:45 UTC35m
2026-05-21 AAL2826 ORD → PHX May 21, 01:05 UTCMay 21, 01:30 UTC25m
2026-05-21 AAL2826 ORD → PHX May 21, 01:00 UTCMay 21, 01:34 UTC34m
2026-05-20 AAL2214 AUS → DFW May 20, 22:15 UTCMay 20, 23:15 UTC1h 0m
2026-05-20 AAL2214 AUS → DFW May 20, 20:05 UTCMay 20, 20:55 UTC50m
2026-05-20 AAL2325 LAX → PHL May 20, 17:00 UTCMay 20, 18:15 UTC1h 15m
2026-05-20 AAL2325 LAX → PHL May 20, 16:55 UTCMay 20, 18:12 UTC1h 17m
2026-05-20 AAL2325 LAX → PHL May 20, 14:30 UTCMay 20, 15:35 UTC1h 5m
2026-05-20 AAL2538 DCA → SYR May 20, 11:35 UTCMay 20, 12:50 UTC1h 15m
2026-05-20 AAL2022 CLT → TPA May 20, 00:20 UTCMay 20, 01:30 UTC1h 10m
2026-05-20 AAL2022 CLT → TPA May 20, 00:16 UTCMay 20, 01:32 UTC1h 16m

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?
Yes. Mode-S A657BF is currently airborne.
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 AAL1943, AAL2325, AAL1012, AAL608, AAL3238.