Apparatus

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sensors Mode-S transponder

A542D7

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N438WN · BOEING 737-700 · operated by SOUTHWEST AIRLINES CO

Hex
A542D7
Octal
51241327
Decimal
10,830,551
Country
US
Tail
N438WN
Type
B737
Broadcasting now · callsign SWA1269 · 8,725 ft
Flights observed
659
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Current position

A542D7 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A542D7 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
SWA2775 Southwest Airlines 7 2026-05-22
SWA342 - 6 2026-06-23
SWA971 Southwest Airlines 5 2026-05-20
SWA482 - 5 2026-07-12
SWA3776 Southwest Airlines 5 2026-04-25
SWA2731 Southwest Airlines 5 2026-04-16
SWA267 Southwest Airlines 5 2026-05-30
SWA2286 Southwest Airlines 5 2026-06-09
SWA149 Southwest Airlines 5 2026-06-16
SWA1323 - 5 2026-06-28
SWA1160 Southwest Airlines 5 2026-05-25
SWA714 - 4 2026-07-11
SWA4756 - 4 2026-07-14
SWA369 - 4 2026-04-13
SWA3129 - 4 2026-06-26
SWA2121 Southwest Airlines 4 2026-06-08
SWA2091 Southwest Airlines 4 2026-04-21
SWA189 - 4 2026-07-04
SWA174 - 4 2026-07-01
SWA1642 Southwest Airlines 4 2026-04-24

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 SWA4204 MSY → LAS Jul 14, 12:00 UTCJul 14, 15:10 UTC3h 10m
2026-07-14 SWA4756 - Jul 14, 04:45 UTCJul 14, 05:40 UTC55m
2026-07-14 SWA4756 HOU → MSY Jul 14, 04:42 UTCJul 14, 05:35 UTC53m
2026-07-14 SWA4493 - Jul 14, 01:45 UTCJul 14, 03:45 UTC2h 0m
2026-07-14 SWA4493 MCO → HOU Jul 14, 01:41 UTCJul 14, 03:46 UTC2h 5m
2026-07-13 SWA760 CVG → MCO Jul 13, 21:45 UTCJul 13, 23:35 UTC1h 50m
2026-07-13 SWA760 - Jul 13, 19:30 UTCJul 13, 20:30 UTC1h 0m
2026-07-13 SWA1534 - Jul 13, 16:30 UTCJul 13, 18:30 UTC2h 0m
2026-07-13 SWA1534 SRQ → BWI Jul 13, 16:26 UTCJul 13, 18:29 UTC2h 4m
2026-07-13 SWA4653 - Jul 13, 13:15 UTCJul 13, 15:35 UTC2h 20m
2026-07-13 SWA4653 MDW → SRQ Jul 13, 13:15 UTCJul 13, 15:35 UTC2h 20m
2026-07-12 SWA1604 DEN → MDW Jul 12, 23:45 UTCJul 13, 01:40 UTC1h 55m
2026-07-12 SWA339 - Jul 12, 20:20 UTCJul 12, 21:55 UTC1h 35m
2026-07-12 SWA1283 - Jul 12, 16:30 UTCJul 12, 19:15 UTC2h 45m
2026-07-12 SWA1283 - Jul 12, 14:20 UTCJul 12, 15:05 UTC45m
2026-07-12 SWA482 OAK → BUR Jul 12, 04:30 UTCJul 12, 05:30 UTC1h 0m
2026-07-12 SWA482 OAK → BUR Jul 12, 04:30 UTCJul 12, 05:29 UTC59m
2026-07-12 SWA2102 - Jul 12, 01:45 UTCJul 12, 03:15 UTC1h 30m
2026-07-11 SWA714 - Jul 11, 23:35 UTCJul 12, 00:35 UTC1h 0m
2026-07-11 SWA714 - Jul 11, 21:30 UTCJul 11, 22:30 UTC1h 0m
2026-07-11 SWA714 - Jul 11, 19:15 UTCJul 11, 20:40 UTC1h 25m
2026-07-11 SWA418 - Jul 11, 17:20 UTCJul 11, 18:20 UTC1h 0m
2026-07-11 SWA418 PHX → SMF Jul 11, 14:35 UTCJul 11, 16:05 UTC1h 30m
2026-07-11 SWA4615 - Jul 11, 01:10 UTCJul 11, 04:01 UTC2h 50m
2026-07-10 SWA3130 DEN → STL Jul 10, 22:00 UTCJul 10, 23:40 UTC1h 40m
2026-07-10 SWA3775 SMF → DEN Jul 10, 19:10 UTCJul 10, 21:05 UTC1h 55m
2026-07-10 SWA4454 - Jul 10, 16:35 UTCJul 10, 17:35 UTC1h 0m
2026-07-10 SWA1840 - Jul 10, 14:20 UTCJul 10, 15:20 UTC1h 0m
2026-07-10 SWA1840 EUG → SMF Jul 10, 12:15 UTCJul 10, 13:10 UTC55m
2026-07-10 SWA3821 DEN → EUG Jul 10, 04:50 UTCJul 10, 07:05 UTC2h 15m
2026-07-10 SWA3570 - Jul 10, 02:20 UTCJul 10, 03:55 UTC1h 35m
2026-07-09 SWA4970 - Jul 9, 22:25 UTCJul 10, 00:50 UTC2h 25m
2026-07-09 SWA2563 SRQ → ATL Jul 9, 16:35 UTCJul 9, 19:25 UTC2h 50m
2026-07-09 SWA2563 SRQ → ATL Jul 9, 16:33 UTCJul 9, 19:21 UTC2h 49m
2026-07-09 SWA2563 SRQ → ATL Jul 9, 13:25 UTCJul 9, 15:30 UTC2h 5m
2026-07-08 SWA3651 - Jul 8, 23:10 UTCJul 9, 00:40 UTC1h 30m
2026-07-08 SWA3334 PHX → SFO Jul 8, 20:10 UTCJul 8, 21:45 UTC1h 35m
2026-07-08 SWA4766 OAK → PHX Jul 8, 17:30 UTCJul 8, 19:03 UTC1h 33m
2026-07-08 SWA4766 OAK → PHX Jul 8, 17:30 UTCJul 8, 19:05 UTC1h 35m
2026-07-08 SWA2452 LAS → OAK Jul 8, 15:00 UTCJul 8, 16:05 UTC1h 5m
2026-07-08 SWA1842 - Jul 8, 12:35 UTCJul 8, 13:20 UTC45m
2026-07-08 SWA4586 - Jul 8, 05:30 UTCJul 8, 06:10 UTC40m
2026-07-08 SWA1951 LAS → LAS Jul 8, 00:55 UTCJul 8, 04:10 UTC3h 15m
2026-07-07 SWA2755 SBA → LAS Jul 7, 21:15 UTCJul 7, 22:05 UTC50m
2026-07-07 SWA4484 LAS → SBA Jul 7, 19:15 UTCJul 7, 20:10 UTC55m
2026-07-07 SWA4484 LAS → SBA Jul 7, 19:15 UTCJul 7, 20:08 UTC53m
2026-07-07 SWA2485 LAX → OAK Jul 7, 01:35 UTCJul 7, 02:20 UTC45m
2026-07-06 SWA2485 LAX → OAK Jul 6, 23:30 UTCJul 7, 00:40 UTC1h 10m
2026-07-06 SWA3870 - Jul 6, 21:30 UTCJul 6, 22:35 UTC1h 5m
2026-07-06 SWA3870 SNA → SMF Jul 6, 21:29 UTCJul 6, 22:34 UTC1h 5m

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 N438WN page for operator, model, and routing details .

Mode-S A542D7 frequently asked

What is Mode-S code A542D7?
A542D7 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N438WN.
Where is Mode-S A542D7 registered?
Mode-S code A542D7 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 A542D7 broadcasting right now?
Yes. Mode-S A542D7 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A542D7, octal 51241327, decimal 10,830,551.
What flights does A542D7 operate?
Mode-S A542D7 has broadcast 20 distinct callsigns, including SWA2775, SWA342, SWA971, SWA482, SWA3776.