sensors Mode-S transponder

A55D31

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N445AA · AIRBUS A-321neo · operated by AMERICAN AIRLINES INC

Hex
A55D31
Octal
51256461
Decimal
10,837,297
Country
US
Tail
N445AA
Type
A21N
No current signal · last broadcast 2h ago
Flights observed
221
Distinct callsigns
20
Country
US
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S A55D31.

Country allocation

The ICAO 24-bit address A55D31 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 AAL2669 PHX → EWR May 29, 20:40 UTCMay 29, 23:05 UTC2h 25m
2026-05-29 AAL2669 PHX → EWR May 29, 16:25 UTCMay 29, 19:15 UTC2h 50m
2026-05-29 AAL2274 ORF → DFW May 29, 11:35 UTCMay 29, 14:25 UTC2h 50m
2026-05-29 AAL2587 DFW → ORF May 29, 00:50 UTCMay 29, 03:20 UTC2h 30m
2026-05-28 AAL3258 LAX → SFO May 28, 20:15 UTCMay 28, 23:20 UTC3h 5m
2026-05-28 AAL3258 LAX → SFO May 28, 20:12 UTCMay 28, 23:15 UTC3h 3m
2026-05-28 AAL1524 MIA → LAS May 28, 12:55 UTCMay 28, 18:30 UTC5h 35m
2026-05-28 AAL3276 PHL → LAX May 28, 05:55 UTCMay 28, 10:30 UTC4h 35m
2026-05-27 AAL266 LIH → LAX May 27, 23:10 UTCMay 28, 04:20 UTC5h 10m
2026-05-27 AAL266 LIH → LAX May 27, 22:59 UTCMay 28, 04:20 UTC5h 21m
2026-05-27 AAL119 DFW → OGG May 27, 15:50 UTCMay 27, 21:05 UTC5h 15m
2026-05-27 AAL119 DFW → OGG May 27, 15:46 UTCMay 27, 21:14 UTC5h 28m
2026-05-27 AAL3328 DFW → LAX May 27, 00:49 UTCMay 27, 05:45 UTC4h 55m
2026-05-26 AAL1456 SAT → ORD May 26, 18:24 UTCMay 26, 22:25 UTC4h 0m
2026-05-26 AAL2991 ORD → PHL May 26, 08:49 UTCMay 26, 13:35 UTC4h 46m
2026-05-26 AAL2991 ORD → PHL May 26, 08:50 UTCMay 26, 13:34 UTC4h 45m
2026-05-26 AAL395 SAN → PHL May 26, 01:24 UTCMay 26, 07:40 UTC6h 15m
2026-05-26 AAL395 SAN → PHL May 26, 01:21 UTCMay 26, 07:38 UTC6h 17m
2026-05-25 AAL3258 LAX → SFO May 25, 20:04 UTCMay 26, 00:00 UTC3h 55m
2026-05-25 AAL1524 MIA → LAS May 25, 12:45 UTCMay 25, 18:15 UTC5h 30m
2026-05-25 AAL1524 MIA → LAS May 25, 12:45 UTCMay 25, 18:16 UTC5h 31m
2026-05-24 AAL2722 RNO → DFW May 24, 23:00 UTCMay 24, 23:10 UTC10m
2026-05-24 AAL2722 RNO → DFW May 24, 18:30 UTCMay 24, 21:45 UTC3h 15m
2026-05-24 AAL2722 RNO → DFW May 24, 18:28 UTCMay 24, 23:05 UTC4h 37m
2026-05-24 AAL1949 SAN → PHX May 24, 13:40 UTCMay 24, 16:45 UTC3h 5m
2026-05-24 AAL2776 BOS → PHL May 24, 06:58 UTCMay 24, 10:22 UTC3h 24m
2026-05-24 AAL2776 BOS → PHL May 24, 07:00 UTCMay 24, 10:25 UTC3h 25m
2026-05-24 AAL1434 BOS → ORD May 24, 01:30 UTCMay 24, 05:35 UTC4h 5m
2026-05-23 AAL3258 LAX → SFO May 23, 20:25 UTCMay 23, 23:25 UTC3h 0m
2026-05-23 AAL3258 LAX → SFO May 23, 20:22 UTCMay 23, 23:19 UTC2h 57m
2026-05-23 AAL1524 MIA → LAS May 23, 13:25 UTCMay 23, 18:50 UTC5h 25m
2026-05-23 AAL1524 MIA → LAS May 23, 13:21 UTCMay 23, 18:55 UTC5h 34m
2026-05-23 AAL1333 SDF → MIA May 23, 05:15 UTCMay 23, 09:50 UTC4h 35m
2026-05-23 AAL1333 SDF → MIA May 23, 05:14 UTCMay 23, 09:49 UTC4h 35m
2026-05-22 AAL1489 CLT → EWR May 22, 20:35 UTCMay 23, 01:30 UTC4h 55m
2026-05-22 AAL2161 BOS → JFK May 22, 13:30 UTCMay 22, 18:20 UTC4h 50m
2026-05-22 AAL2426 MIA → SFO May 22, 01:00 UTCMay 22, 06:30 UTC5h 30m
2026-05-21 AAL2517 LAX → DFW May 21, 16:55 UTCMay 21, 22:35 UTC5h 40m
2026-05-21 AAL2184 PHL → MIA May 21, 12:25 UTCMay 21, 14:40 UTC2h 15m
2026-05-20 AAL3161 DFW → GJT May 20, 20:10 UTCMay 21, 00:20 UTC4h 10m
2026-05-20 AAL2940 PHX → PHL May 20, 14:20 UTCMay 20, 18:30 UTC4h 10m
2026-05-20 AAL980 ATL → DFW May 20, 07:46 UTCMay 20, 11:54 UTC4h 8m
2026-05-20 AAL980 ATL → DFW May 20, 07:50 UTCMay 20, 11:55 UTC4h 5m
2026-05-19 AAL246 JFK → FCO May 19, 03:45 UTCMay 19, 04:25 UTC40m
2026-05-18 AAL246 JFK → FCO May 18, 23:35 UTCMay 18, 23:45 UTC10m
2026-05-18 AAL246 JFK → FCO May 18, 21:45 UTCMay 18, 21:50 UTC5m
2026-05-18 AAL246 JFK → FCO May 18, 16:35 UTCMay 18, 17:05 UTC30m
2026-05-18 AAL2296 MSN → CLT May 18, 02:30 UTCMay 18, 07:35 UTC5h 5m
2026-05-17 AAL779 BOS → LAX May 17, 18:01 UTCMay 17, 22:30 UTC4h 30m
2026-05-17 AAL2236 LGA → DCA May 17, 11:55 UTCMay 17, 16:30 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 N445AA page for operator, model, and routing details .

Mode-S A55D31 frequently asked

What is Mode-S code A55D31?
A55D31 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N445AA.
Where is Mode-S A55D31 registered?
Mode-S code A55D31 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 A55D31 broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A55D31, octal 51256461, decimal 10,837,297.
What flights does A55D31 operate?
Mode-S A55D31 has broadcast 20 distinct callsigns, including AAL3258, AAL2585, AAL1524, AAL144, AAL3272.