Apparatus

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sensors Mode-S transponder

AC42DF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8899H · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC42DF
Octal
53041337
Decimal
11,289,311
Country
US
Tail
N8899H
Type
B38M
Transponder active on ground
Flights observed
668
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S AC42DF.

Country allocation

The ICAO 24-bit address AC42DF 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
SWA2659 - 5 2026-07-14
SWA1266 Southwest Airlines 5 2026-04-15
SWA724 Southwest Airlines 4 2026-06-29
SWA3157 Southwest Airlines 4 2026-04-29
SWA2939 Southwest Airlines 4 2026-04-17
SWA2359 Southwest Airlines 4 2026-05-19
SWA1988 Southwest Airlines 4 2026-05-12
SWA1532 - 4 2026-06-17
SWA1528 - 4 2026-04-13
SWA927 Southwest Airlines 3 2026-04-26
SWA884 - 3 2026-06-29
SWA693 - 3 2026-07-08
SWA533 - 3 2026-07-04
SWA512 Southwest Airlines 3 2026-05-08
SWA485 - 3 2026-07-11
SWA4627 Southwest Airlines 3 2026-07-02
SWA3769 Southwest Airlines 3 2026-06-04
SWA3452 - 3 2026-07-03
SWA3356 Southwest Airlines 3 2026-06-06
SWA3331 - 3 2026-07-02

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 SWA2993 SMF → DEN Jul 14, 23:05 UTCJul 15, 01:00 UTC1h 55m
2026-07-14 SWA3870 - Jul 14, 20:45 UTCJul 14, 21:45 UTC1h 0m
2026-07-14 SWA3244 - Jul 14, 18:50 UTCJul 14, 19:40 UTC50m
2026-07-14 SWA1855 SJC → PHX Jul 14, 13:20 UTCJul 14, 14:50 UTC1h 30m
2026-07-14 SWA2659 - Jul 14, 03:10 UTCJul 14, 06:45 UTC3h 35m
2026-07-14 SWA2659 MDW → SJC Jul 14, 03:06 UTCJul 14, 06:41 UTC3h 35m
2026-07-13 SWA2659 MCO → MDW Jul 13, 23:45 UTCJul 14, 02:00 UTC2h 15m
2026-07-13 SWA2819 - Jul 13, 19:15 UTCJul 13, 22:05 UTC2h 50m
2026-07-13 SWA4077 - Jul 13, 15:25 UTCJul 13, 17:50 UTC2h 25m
2026-07-13 SWA4932 - Jul 13, 12:15 UTCJul 13, 14:30 UTC2h 15m
2026-07-13 SWA4161 LAS → SLC Jul 13, 05:40 UTCJul 13, 06:40 UTC1h 0m
2026-07-13 SWA4161 LAS → SLC Jul 13, 05:39 UTCJul 13, 06:36 UTC57m
2026-07-13 SWA1951 GEG → LAS Jul 13, 01:15 UTCJul 13, 03:10 UTC1h 55m
2026-07-12 SWA1951 - Jul 12, 20:45 UTCJul 13, 00:01 UTC3h 15m
2026-07-12 SWA3610 - Jul 12, 18:45 UTCJul 12, 19:35 UTC50m
2026-07-12 SWA3610 TPA → SDF Jul 12, 15:55 UTCJul 12, 17:35 UTC1h 40m
2026-07-12 SWA222 DEN → TPA Jul 12, 11:45 UTCJul 12, 14:45 UTC3h 0m
2026-07-12 SWA506 - Jul 12, 03:05 UTCJul 12, 05:30 UTC2h 25m
2026-07-12 SWA4636 - Jul 12, 00:10 UTCJul 12, 01:20 UTC1h 10m
2026-07-11 SWA3430 - Jul 11, 21:30 UTCJul 11, 23:20 UTC1h 50m
2026-07-11 SWA3430 MCI → ECP Jul 11, 21:24 UTCJul 11, 23:16 UTC1h 52m
2026-07-11 SWA1374 - Jul 11, 17:40 UTCJul 11, 20:30 UTC2h 50m
2026-07-11 SWA485 DAL → PDX Jul 11, 12:50 UTCJul 11, 16:20 UTC3h 30m
2026-07-11 SWA485 DAL → PDX Jul 11, 12:48 UTCJul 11, 16:19 UTC3h 32m
2026-07-11 SWA485 BNA → DAL Jul 11, 10:25 UTCJul 11, 11:45 UTC1h 20m
2026-07-11 SWA1852 - Jul 11, 00:45 UTCJul 11, 02:35 UTC1h 50m
2026-07-10 SWA204 ATL → FLL Jul 10, 19:15 UTCJul 10, 20:50 UTC1h 35m
2026-07-10 SWA862 - Jul 10, 16:50 UTCJul 10, 18:15 UTC1h 25m
2026-07-10 SWA1281 DAL → BWI Jul 10, 12:30 UTCJul 10, 15:15 UTC2h 45m
2026-07-10 SWA2445 - Jul 10, 10:35 UTCJul 10, 11:25 UTC50m
2026-07-10 SWA4789 - Jul 10, 03:45 UTCJul 10, 04:25 UTC40m
2026-07-09 SWA1404 SEA → DAL Jul 9, 23:00 UTCJul 10, 02:50 UTC3h 50m
2026-07-09 SWA4130 DEN → SEA Jul 9, 18:45 UTCJul 9, 21:15 UTC2h 30m
2026-07-09 SWA3042 - Jul 9, 15:25 UTCJul 9, 17:20 UTC1h 55m
2026-07-09 SWA3042 - Jul 9, 13:25 UTCJul 9, 14:20 UTC55m
2026-07-09 SWA457 SJC → ONT Jul 9, 05:10 UTCJul 9, 06:05 UTC55m
2026-07-09 SWA3865 LAS → SJC Jul 9, 03:15 UTCJul 9, 04:20 UTC1h 5m
2026-07-09 SWA3865 LAS → SJC Jul 9, 03:15 UTCJul 9, 04:23 UTC1h 8m
2026-07-09 SWA1564 DEN → LAS Jul 9, 00:50 UTCJul 9, 02:10 UTC1h 20m
2026-07-08 SWA2455 LGA → DEN Jul 8, 18:55 UTCJul 8, 23:10 UTC4h 15m
2026-07-08 SWA1966 BNA → LGA Jul 8, 15:30 UTCJul 8, 17:35 UTC2h 5m
2026-07-08 SWA1519 SJC → BUR Jul 8, 12:15 UTCJul 8, 13:45 UTC1h 30m
2026-07-08 SWA1519 SJC → BUR Jul 8, 12:15 UTCJul 8, 13:37 UTC1h 22m
2026-07-08 SWA693 - Jul 8, 01:00 UTCJul 8, 03:45 UTC2h 45m
2026-07-08 SWA693 BWI → DAL Jul 8, 01:00 UTCJul 8, 03:37 UTC2h 38m
2026-07-07 SWA2856 MCO → BWI Jul 7, 21:00 UTCJul 7, 22:50 UTC1h 50m
2026-07-07 SWA2856 MCO → BWI Jul 7, 21:00 UTCJul 7, 22:48 UTC1h 48m
2026-07-07 SWA2818 - Jul 7, 17:40 UTCJul 7, 19:50 UTC2h 10m
2026-07-07 SWA2818 - Jul 7, 15:10 UTCJul 7, 16:10 UTC1h 0m
2026-07-07 SWA1243 - Jul 7, 13:00 UTCJul 7, 13:55 UTC55m

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 N8899H page for operator, model, and routing details .

Mode-S AC42DF frequently asked

What is Mode-S code AC42DF?
AC42DF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8899H.
Where is Mode-S AC42DF registered?
Mode-S code AC42DF 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 AC42DF broadcasting right now?
Mode-S AC42DF is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC42DF, octal 53041337, decimal 11,289,311.
What flights does AC42DF operate?
Mode-S AC42DF has broadcast 20 distinct callsigns, including SWA2659, SWA1266, SWA724, SWA3157, SWA2939.