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
No current signal · last broadcast Jul 17, 03:05 UTC
Flights observed
684
Distinct callsigns
20
Country
US
Last broadcast
Jul 17, 03:05 UTC

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
SWA4005 - 4 2026-07-16
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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-17 SWA490 BNA → DAL Jul 17, 01:35 UTCJul 17, 03:05 UTC1h 30m
2026-07-17 SWA490 BNA → DAL Jul 17, 01:32 UTCJul 17, 03:00 UTC1h 28m
2026-07-16 SWA4005 - Jul 16, 22:35 UTCJul 16, 23:44 UTC1h 10m
2026-07-16 SWA4005 TPA → BNA Jul 16, 22:31 UTCJul 16, 23:55 UTC1h 24m
2026-07-16 SWA3193 COS → DEN Jul 16, 20:19 UTCJul 16, 21:25 UTC1h 5m
2026-07-16 SWA3193 COS → DEN Jul 16, 16:55 UTCJul 16, 19:10 UTC2h 15m
2026-07-16 SWA3890 - Jul 16, 13:20 UTCJul 16, 15:00 UTC1h 40m
2026-07-16 SWA2323 - Jul 16, 05:00 UTCJul 16, 05:45 UTC45m
2026-07-16 SWA1390 - Jul 16, 03:10 UTCJul 16, 04:00 UTC50m
2026-07-16 SWA1390 TUS → LAS Jul 16, 03:05 UTCJul 16, 04:03 UTC58m
2026-07-16 SWA989 - Jul 16, 01:10 UTCJul 16, 02:20 UTC1h 10m
2026-07-15 SWA363 - Jul 15, 21:25 UTCJul 16, 00:05 UTC2h 40m
2026-07-15 SWA868 LAS → AUS Jul 15, 17:20 UTCJul 15, 19:40 UTC2h 20m
2026-07-15 SWA868 SJC → LAS Jul 15, 15:00 UTCJul 15, 16:00 UTC1h 0m
2026-07-15 SWA2346 LAS → SJC Jul 15, 12:50 UTCJul 15, 13:50 UTC1h 0m
2026-07-15 SWA1566 DEN → LAS Jul 15, 02:20 UTCJul 15, 03:40 UTC1h 20m
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

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?
No active broadcast right now. Last signal was Jul 17, 03:05 UTC.
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, SWA4005, SWA3157.