sensors Mode-S transponder

AC1720

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8785L · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC1720
Octal
53013440
Decimal
11,278,112
Country
US
Tail
N8785L
Type
B38M
No current signal · last broadcast 14h ago
Flights observed
17
Distinct callsigns
8
Country
US
Last broadcast
14h ago

Last known position

Most recent position reported by Mode-S AC1720.

Country allocation

The ICAO 24-bit address AC1720 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 8 distinct

Callsign Airline Flights Last seen
SWA3708 Southwest Airlines 4 2026-04-13
SWA873 - 3 2026-04-13
SWA4690 - 3 2026-04-13
SWA2672 - 3 2026-04-13
SWA4695 - 1 2026-04-13
SWA4039 - 1 2026-04-13
SWA2236 - 1 2026-04-14
SWA1397 - 1 2026-04-13

Recent flights last 17

DateFlightRouteTakeoffLandingDuration
2026-04-14 SWA2236 - Apr 14, 10:45 UTCApr 14, 11:05 UTC20m
2026-04-13 SWA4039 - Apr 13, 21:48 UTCApr 14, 00:04 UTC2h 16m
2026-04-13 SWA4690 - Apr 13, 19:50 UTCApr 13, 20:50 UTC1h 0m
2026-04-13 SWA4690 - Apr 13, 18:16 UTCApr 13, 20:39 UTC2h 23m
2026-04-13 SWA4690 - Apr 13, 18:29 UTCApr 13, 20:50 UTC2h 21m
2026-04-13 SWA2672 - Apr 13, 16:15 UTCApr 13, 17:10 UTC55m
2026-04-13 SWA2672 - Apr 13, 15:50 UTCApr 13, 17:10 UTC1h 20m
2026-04-13 SWA2672 - Apr 13, 15:33 UTCApr 13, 17:01 UTC1h 28m
2026-04-13 SWA1397 - Apr 13, 13:05 UTCApr 13, 14:30 UTC1h 25m
2026-04-13 SWA3708 PHL → DEN Apr 13, 08:25 UTCApr 13, 10:30 UTC2h 5m
2026-04-13 SWA3708 PHL → DEN Apr 13, 07:55 UTCApr 13, 10:30 UTC2h 35m
2026-04-13 SWA3708 PHL → DEN Apr 13, 07:06 UTCApr 13, 10:44 UTC3h 38m
2026-04-13 SWA3708 PHL → DEN Apr 13, 06:54 UTCApr 13, 10:34 UTC3h 40m
2026-04-13 SWA873 - Apr 13, 04:20 UTCApr 13, 05:15 UTC55m
2026-04-13 SWA873 - Apr 13, 04:05 UTCApr 13, 05:15 UTC1h 10m
2026-04-13 SWA873 - Apr 13, 03:46 UTCApr 13, 05:05 UTC1h 19m
2026-04-13 SWA4695 - Apr 13, 01:40 UTCApr 13, 02:20 UTC40m

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 N8785L page for operator, model, and routing details .

Mode-S AC1720 frequently asked

What is Mode-S code AC1720?
AC1720 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8785L.
Where is Mode-S AC1720 registered?
Mode-S code AC1720 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 AC1720 broadcasting right now?
No active broadcast right now. Last signal was 14h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC1720, octal 53013440, decimal 11,278,112.
What flights does AC1720 operate?
Mode-S AC1720 has broadcast 8 distinct callsigns, including SWA3708, SWA873, SWA4690, SWA2672, SWA4695.