Apparatus

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sensors Mode-S transponder

A51F0F

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N429WN · BOEING 737-700 · operated by SOUTHWEST AIRLINES CO

Hex
A51F0F
Octal
51217417
Decimal
10,821,391
Country
US
Tail
N429WN
Type
B737
No current signal · last broadcast Jul 26, 20:05 UTC
Flights observed
749
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 20:05 UTC

Last known position

Most recent position reported by Mode-S A51F0F.

Country allocation

The ICAO 24-bit address A51F0F 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
SWA1655 Southwest Airlines 8 2026-04-17
SWA2278 Southwest Airlines 7 2026-04-14
SWA800 Southwest Airlines 6 2026-07-19
SWA3816 - 6 2026-07-02
SWA3335 Southwest Airlines 6 2026-05-27
SWA121 - 6 2026-07-01
SWA955 - 5 2026-06-22
SWA519 - 5 2026-06-22
SWA4272 Southwest Airlines 5 2026-05-29
SWA375 Southwest Airlines 5 2026-07-23
SWA345 - 5 2026-07-04
SWA1375 Southwest Airlines 5 2026-05-04
SWA11 Southwest Airlines 5 2026-06-16
SWA686 Southwest Airlines 4 2026-07-25
SWA4866 - 4 2026-07-17
SWA4516 - 4 2026-07-17
SWA4290 Southwest Airlines 4 2026-07-21
SWA38 Southwest Airlines 4 2026-06-03
SWA3226 - 4 2026-07-18
SWA297 - 4 2026-06-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SWA109 PVR → HOU Jul 26, 14:45 UTCJul 26, 20:05 UTC5h 20m
2026-07-26 SWA4456 SJC → PDX Jul 26, 11:50 UTCJul 26, 13:20 UTC1h 30m
2026-07-26 SWA559 SAN → SJC Jul 26, 00:35 UTCJul 26, 02:55 UTC2h 20m
2026-07-25 SWA686 DCA → MDW Jul 25, 22:15 UTCJul 25, 23:40 UTC1h 25m
2026-07-25 SWA686 DCA → MDW Jul 25, 19:45 UTCJul 25, 21:10 UTC1h 25m
2026-07-25 SWA686 DCA → MDW Jul 25, 18:10 UTCJul 25, 18:50 UTC40m
2026-07-25 SWA686 DCA → MDW Jul 25, 15:50 UTCJul 25, 17:15 UTC1h 25m
2026-07-25 SWA4632 ONT → OAK Jul 25, 13:30 UTCJul 25, 14:50 UTC1h 20m
2026-07-25 SWA4553 MDW → SDF Jul 25, 02:40 UTCJul 25, 03:25 UTC45m
2026-07-25 SWA4415 PHX → CLE Jul 25, 01:00 UTCJul 25, 01:45 UTC45m
2026-07-24 SWA1316 SJC → BOI Jul 24, 23:05 UTCJul 24, 23:55 UTC50m
2026-07-24 SWA1316 SJC → BOI Jul 24, 20:35 UTCJul 24, 22:15 UTC1h 40m
2026-07-24 SWA1478 MCI → MCO Jul 24, 18:30 UTCJul 24, 19:30 UTC1h 0m
2026-07-24 SWA4027 SMF → GEG Jul 24, 16:27 UTCJul 24, 17:30 UTC1h 3m
2026-07-24 SWA4027 SMF → GEG Jul 24, 16:30 UTCJul 24, 17:35 UTC1h 5m
2026-07-24 SWA3233 TPA → CMH Jul 24, 03:45 UTCJul 24, 05:05 UTC1h 20m
2026-07-24 SWA3088 DCA → DAL Jul 24, 02:05 UTCJul 24, 03:00 UTC55m
2026-07-24 SWA3088 DCA → DAL Jul 24, 02:01 UTCJul 24, 02:55 UTC54m
2026-07-24 SWA3088 DCA → DAL Jul 24, 00:10 UTCJul 24, 01:20 UTC1h 10m
2026-07-23 SWA375 DEN → OAK Jul 23, 22:15 UTCJul 23, 23:10 UTC55m
2026-07-23 SWA375 DEN → OAK Jul 23, 22:10 UTCJul 23, 23:07 UTC58m
2026-07-23 SWA375 DEN → OAK Jul 23, 20:20 UTCJul 23, 21:10 UTC50m
2026-07-23 SWA375 DEN → OAK Jul 23, 17:20 UTCJul 23, 19:15 UTC1h 55m
2026-07-23 SWA375 DEN → OAK Jul 23, 12:25 UTCJul 23, 16:10 UTC3h 45m
2026-07-23 SWA1374 DEN → AUS Jul 23, 00:20 UTCJul 23, 02:00 UTC1h 40m
2026-07-22 SWA2273 PSP → OAK Jul 22, 19:55 UTCJul 22, 23:05 UTC3h 10m
2026-07-22 SWA2273 PSP → OAK Jul 22, 19:53 UTCJul 22, 22:54 UTC3h 1m
2026-07-22 SWA2273 PSP → OAK Jul 22, 17:00 UTCJul 22, 18:00 UTC1h 0m
2026-07-22 SWA4802 PHX → FLL Jul 22, 14:50 UTCJul 22, 15:50 UTC1h 0m
2026-07-22 SWA2396 BWI → LAS Jul 22, 05:20 UTCJul 22, 06:21 UTC1h 1m
2026-07-22 SWA3487 HOU → MSY Jul 22, 02:40 UTCJul 22, 04:25 UTC1h 45m
2026-07-21 SWA4769 ALB → FLL Jul 21, 22:50 UTCJul 22, 01:05 UTC2h 15m
2026-07-21 SWA4290 PDX → LAS Jul 21, 20:20 UTCJul 21, 21:35 UTC1h 15m
2026-07-21 SWA4290 PDX → LAS Jul 21, 20:17 UTCJul 21, 21:30 UTC1h 13m
2026-07-21 SWA2325 SNA → OAK Jul 21, 17:45 UTCJul 21, 18:55 UTC1h 10m
2026-07-21 SWA2325 SNA → OAK Jul 21, 15:45 UTCJul 21, 16:30 UTC45m
2026-07-21 SWA321 DEN → CLE Jul 21, 11:20 UTCJul 21, 13:30 UTC2h 10m
2026-07-21 SWA1953 LAX → OAK Jul 21, 05:00 UTCJul 21, 05:30 UTC30m
2026-07-21 SWA1953 LAX → OAK Jul 21, 04:55 UTCJul 21, 05:24 UTC29m
2026-07-21 SWA606 - Jul 21, 01:50 UTCJul 21, 03:45 UTC1h 55m
2026-07-20 SWA1382 LAS → DEN Jul 20, 22:45 UTCJul 21, 00:15 UTC1h 29m
2026-07-20 SWA1382 PHX → LAS Jul 20, 20:25 UTCJul 20, 21:15 UTC50m
2026-07-20 SWA1382 DAL → PHX Jul 20, 17:25 UTCJul 20, 19:20 UTC1h 55m
2026-07-20 SWA3906 IAD → DEN Jul 20, 13:40 UTCJul 20, 16:25 UTC2h 45m
2026-07-20 SWA4871 ATL → PHL Jul 20, 04:35 UTCJul 20, 05:45 UTC1h 10m
2026-07-20 SWA807 BUR → OAK Jul 20, 03:00 UTCJul 20, 03:45 UTC45m
2026-07-20 SWA2201 - Jul 20, 01:15 UTCJul 20, 01:45 UTC30m
2026-07-20 SWA2201 LAS → BUR Jul 20, 01:12 UTCJul 20, 01:53 UTC41m
2026-07-19 SWA2406 AUS → SMF Jul 19, 21:55 UTCJul 19, 23:40 UTC1h 45m
2026-07-19 SWA2178 SJC → LAX Jul 19, 19:20 UTCJul 19, 21:00 UTC1h 40m

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 N429WN page for operator, model, and routing details .

Mode-S A51F0F frequently asked

What is Mode-S code A51F0F?
A51F0F is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N429WN.
Where is Mode-S A51F0F registered?
Mode-S code A51F0F 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 A51F0F broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 20:05 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A51F0F, octal 51217417, decimal 10,821,391.
What flights does A51F0F operate?
Mode-S A51F0F has broadcast 20 distinct callsigns, including SWA1655, SWA2278, SWA800, SWA3816, SWA3335.