sensors Mode-S transponder

AC66AA

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8989L · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC66AA
Octal
53063252
Decimal
11,298,474
Country
US
Tail
N8989L
Type
B38M
Broadcasting now · callsign SWA1252 · 41,000 ft
Flights observed
9
Distinct callsigns
8
Country
US
Last broadcast
1d ago

Current position

AC66AA is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AC66AA 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
SWA888 - 2 2026-04-13
SWA940 Southwest Airlines 1 2026-04-13
SWA3685 - 1 2026-04-13
SWA2987 - 1 2026-04-13
SWA2506 - 1 2026-04-12
SWA2150 - 1 2026-04-13
SWA1580 - 1 2026-04-13
SWA1280 - 1 2026-04-12

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-04-13 SWA3685 ORD → MCO Apr 13, 21:05 UTCApr 13, 23:10 UTC2h 5m
2026-04-13 SWA940 DAL → MAF Apr 13, 16:45 UTCApr 13, 19:05 UTC2h 20m
2026-04-13 SWA1580 - Apr 13, 13:20 UTCApr 13, 15:30 UTC2h 10m
2026-04-13 SWA2987 - Apr 13, 11:04 UTCApr 13, 11:57 UTC53m
2026-04-13 SWA2150 - Apr 13, 04:35 UTCApr 13, 05:18 UTC43m
2026-04-13 SWA888 - Apr 13, 00:20 UTCApr 13, 03:30 UTC3h 10m
2026-04-12 SWA888 - Apr 12, 23:55 UTCApr 13, 03:30 UTC3h 35m
2026-04-12 SWA1280 - Apr 12, 19:45 UTCApr 12, 20:15 UTC30m
2026-04-12 SWA2506 - Apr 12, 17:15 UTCApr 12, 18:30 UTC1h 15m

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 N8989L page for operator, model, and routing details .

Mode-S AC66AA frequently asked

What is Mode-S code AC66AA?
AC66AA is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8989L.
Where is Mode-S AC66AA registered?
Mode-S code AC66AA 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 AC66AA broadcasting right now?
Yes. Mode-S AC66AA is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC66AA, octal 53063252, decimal 11,298,474.
What flights does AC66AA operate?
Mode-S AC66AA has broadcast 8 distinct callsigns, including SWA888, SWA940, SWA3685, SWA2987, SWA2506.