Apparatus

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sensors Mode-S transponder

A18B71

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N199UW · AIRBUS A-321 · operated by AMERICAN AIRLINES INC

Hex
A18B71
Octal
50305561
Decimal
10,586,993
Country
US
Tail
N199UW
Type
A321
Broadcasting now · callsign AAL2677 · 34,000 ft
Flights observed
555
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:35 UTC

Current position

A18B71 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A18B71 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
AAL3001 - 9 2026-06-30
AAL1999 - 8 2026-06-19
AAL3064 American Airlines 6 2026-07-03
AAL2279 American Airlines 5 2026-06-11
AAL1663 American Airlines 5 2026-07-25
AAL1483 American Airlines 5 2026-04-27
AAL573 American Airlines 4 2026-05-21
AAL461 American Airlines 4 2026-05-22
AAL3139 American Airlines 4 2026-06-10
AAL2990 American Airlines 4 2026-07-23
AAL2890 American Airlines 4 2026-05-16
AAL2826 - 4 2026-07-03
AAL2602 - 4 2026-07-03
AAL2582 American Airlines 4 2026-04-27
AAL2482 American Airlines 4 2026-05-30
AAL2466 - 4 2026-07-10
AAL2411 American Airlines 4 2026-05-14
AAL2369 American Airlines 4 2026-04-17
AAL1896 American Airlines 4 2026-06-09
AAL1865 - 4 2026-07-15

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 AAL973 JFK → GIG Jul 26, 16:35 UTCJul 26, 21:35 UTC5h 0m
2026-07-26 AAL3187 LGA → DCA Jul 26, 13:15 UTCJul 26, 15:05 UTC1h 50m
2026-07-26 AAL3187 LGA → DCA Jul 26, 11:35 UTCJul 26, 11:50 UTC15m
2026-07-26 AAL514 DFW → CLT Jul 26, 08:50 UTCJul 26, 09:00 UTC10m
2026-07-26 AAL514 DFW → CLT Jul 26, 04:40 UTCJul 26, 07:15 UTC2h 36m
2026-07-26 AAL1662 DFW → PHL Jul 26, 00:40 UTCJul 26, 02:55 UTC2h 15m
2026-07-25 AAL1662 DFW → PHL Jul 25, 21:25 UTCJul 25, 23:35 UTC2h 10m
2026-07-25 AAL2607 CHS → PHL Jul 25, 17:50 UTCJul 25, 19:55 UTC2h 5m
2026-07-25 AAL2607 CHS → PHL Jul 25, 13:55 UTCJul 25, 16:05 UTC2h 10m
2026-07-25 AAL1663 PHL → BDL Jul 25, 00:35 UTCJul 25, 02:45 UTC2h 10m
2026-07-25 AAL1663 PHL → BDL Jul 25, 00:32 UTCJul 25, 02:41 UTC2h 9m
2026-07-24 AAL3220 SBP → PHX Jul 24, 19:00 UTCJul 24, 22:55 UTC3h 55m
2026-07-24 AAL1274 MCO → AUS Jul 24, 13:55 UTCJul 24, 17:35 UTC3h 40m
2026-07-24 AAL1274 MCO → AUS Jul 24, 13:53 UTCJul 24, 17:33 UTC3h 40m
2026-07-24 AAL2319 DFW → MSY Jul 24, 06:00 UTCJul 24, 07:50 UTC1h 50m
2026-07-24 AAL2319 DFW → MSY Jul 24, 05:57 UTCJul 24, 07:49 UTC1h 52m
2026-07-24 AAL1711 ORD → PVD Jul 24, 01:20 UTCJul 24, 04:20 UTC3h 0m
2026-07-23 AAL2860 SFO → PHX Jul 23, 22:15 UTCJul 23, 23:45 UTC1h 30m
2026-07-23 AAL2990 CLT → BOS Jul 23, 16:45 UTCJul 23, 18:40 UTC1h 55m
2026-07-23 AAL2990 CLT → BOS Jul 23, 16:40 UTCJul 23, 18:40 UTC2h 0m
2026-07-23 AAL484 CLT → EWR Jul 23, 12:17 UTCJul 23, 15:22 UTC3h 5m
2026-07-23 AAL484 CLT → EWR Jul 23, 12:20 UTCJul 23, 15:20 UTC3h 0m
2026-07-23 AAL1446 BDL → CLT Jul 23, 03:01 UTCJul 23, 06:20 UTC3h 19m
2026-07-23 AAL1446 BDL → CLT Jul 23, 03:05 UTCJul 23, 06:25 UTC3h 20m
2026-07-22 AAL1663 PHL → BDL Jul 22, 23:30 UTCJul 23, 01:30 UTC2h 0m
2026-07-22 AAL1994 DFW → TPA Jul 22, 20:25 UTCJul 22, 21:25 UTC1h 0m
2026-07-22 AAL2869 AUS → LAX Jul 22, 18:05 UTCJul 22, 19:05 UTC1h 0m
2026-07-22 AAL1678 - Jul 22, 13:05 UTCJul 22, 16:45 UTC3h 40m
2026-07-22 AAL559 PHX → SAN Jul 22, 03:35 UTCJul 22, 04:25 UTC50m
2026-07-21 AAL2982 PWM → DCA Jul 21, 22:15 UTCJul 22, 02:15 UTC4h 0m
2026-07-21 AAL345 CLT → MSP Jul 21, 15:15 UTCJul 21, 18:15 UTC3h 0m
2026-07-21 AAL345 CLT → MSP Jul 21, 15:10 UTCJul 21, 20:15 UTC5h 5m
2026-07-21 AAL738 LGA → IAH Jul 21, 05:45 UTCJul 21, 10:35 UTC4h 50m
2026-07-21 AAL738 LGA → IAH Jul 21, 05:42 UTCJul 21, 10:40 UTC4h 58m
2026-07-21 AAL2076 YHZ → PHL Jul 21, 01:30 UTCJul 21, 04:00 UTC2h 30m
2026-07-20 AAL1024 - Jul 20, 18:40 UTCJul 20, 23:50 UTC5h 10m
2026-07-20 AAL1996 - Jul 20, 13:45 UTCJul 20, 16:25 UTC2h 40m
2026-07-20 AAL1996 DFW → LAX Jul 20, 13:42 UTCJul 20, 16:25 UTC2h 43m
2026-07-20 AAL2458 SAN → DFW Jul 20, 03:50 UTCJul 20, 06:30 UTC2h 40m
2026-07-19 AAL2458 DFW → SAN Jul 19, 23:40 UTCJul 20, 02:10 UTC2h 30m
2026-07-19 AAL1215 - Jul 19, 15:45 UTCJul 19, 21:40 UTC5h 55m
2026-07-19 AAL1902 ELP → DFW Jul 19, 12:10 UTCJul 19, 13:55 UTC1h 45m
2026-07-19 AAL1543 ORD → SAN Jul 19, 06:20 UTCJul 19, 09:55 UTC3h 35m
2026-07-19 AAL2458 - Jul 19, 00:10 UTCJul 19, 02:40 UTC2h 30m
2026-07-18 AAL2195 SLC → DFW Jul 18, 14:10 UTCJul 18, 16:20 UTC2h 10m
2026-07-18 AAL2195 SLC → DFW Jul 18, 14:09 UTCJul 18, 16:24 UTC2h 15m
2026-07-18 AAL558 - Jul 18, 00:15 UTCJul 18, 02:35 UTC2h 20m
2026-07-17 AAL1973 - Jul 17, 19:09 UTCJul 17, 22:25 UTC3h 15m
2026-07-17 AAL1973 DFW → YYC Jul 17, 14:35 UTCJul 17, 17:44 UTC3h 10m
2026-07-17 AAL3180 - Jul 17, 10:05 UTCJul 17, 12:19 UTC2h 15m

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 N199UW page for operator, model, and routing details .

Mode-S A18B71 frequently asked

What is Mode-S code A18B71?
A18B71 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N199UW.
Where is Mode-S A18B71 registered?
Mode-S code A18B71 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 A18B71 broadcasting right now?
Yes. Mode-S A18B71 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A18B71, octal 50305561, decimal 10,586,993.
What flights does A18B71 operate?
Mode-S A18B71 has broadcast 20 distinct callsigns, including AAL3001, AAL1999, AAL3064, AAL2279, AAL1663.