sensors Mode-S transponder

AC72E4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N901AA · AIRBUS A-321 · operated by AMERICAN AIRLINES INC

Hex
AC72E4
Octal
53071344
Decimal
11,301,604
Country
US
Tail
N901AA
Type
A321
No current signal · last broadcast 19h ago
Flights observed
19
Distinct callsigns
5
Country
US
Last broadcast
19h ago

Last known position

Most recent position reported by Mode-S AC72E4.

Country allocation

The ICAO 24-bit address AC72E4 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 5 distinct

Callsign Airline Flights Last seen
AAL1669 American Airlines 7 2026-04-13
AAL2534 American Airlines 4 2026-04-13
AAL1832 - 4 2026-04-13
AAL1956 - 3 2026-04-14
AAL2567 - 1 2026-04-14

Recent flights last 19

DateFlightRouteTakeoffLandingDuration
2026-04-14 AAL1956 - Apr 14, 09:10 UTCApr 14, 10:10 UTC1h 0m
2026-04-14 AAL1956 - Apr 14, 07:10 UTCApr 14, 09:05 UTC1h 55m
2026-04-14 AAL1956 - Apr 14, 06:54 UTCApr 14, 10:12 UTC3h 18m
2026-04-14 AAL2567 - Apr 14, 05:15 UTCApr 14, 05:55 UTC40m
2026-04-13 AAL1832 - Apr 13, 23:20 UTCApr 13, 23:45 UTC25m
2026-04-13 AAL1832 DFW → DEN Apr 13, 20:25 UTCApr 13, 21:55 UTC1h 30m
2026-04-13 AAL2534 MSY → DCA Apr 13, 16:15 UTCApr 13, 18:15 UTC2h 0m
2026-04-13 AAL2534 MSY → DCA Apr 13, 15:50 UTCApr 13, 18:28 UTC2h 38m
2026-04-13 AAL2534 MSY → DCA Apr 13, 12:20 UTCApr 13, 14:20 UTC2h 0m
2026-04-13 AAL2534 MSY → DCA Apr 13, 12:10 UTCApr 13, 12:15 UTC5m
2026-04-13 AAL1669 MSY → DCA Apr 13, 08:20 UTCApr 13, 09:25 UTC1h 5m
2026-04-13 AAL1669 MSY → DCA Apr 13, 07:55 UTCApr 13, 09:25 UTC1h 30m
2026-04-13 AAL1669 MSY → DCA Apr 13, 07:16 UTCApr 13, 09:46 UTC2h 30m
2026-04-13 AAL1669 MSY → DCA Apr 13, 07:04 UTCApr 13, 09:24 UTC2h 20m
2026-04-13 AAL1669 MSY → DCA Apr 13, 04:20 UTCApr 13, 05:50 UTC1h 30m
2026-04-13 AAL1669 MSY → DCA Apr 13, 03:55 UTCApr 13, 05:50 UTC1h 55m
2026-04-13 AAL1669 MSY → DCA Apr 13, 02:39 UTCApr 13, 05:36 UTC2h 57m
2026-04-13 AAL1832 - Apr 13, 00:20 UTCApr 13, 01:30 UTC1h 10m
2026-04-13 AAL1832 DEN → DFW Apr 13, 00:01 UTCApr 13, 01:30 UTC1h 29m

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 N901AA page for operator, model, and routing details .

Mode-S AC72E4 frequently asked

What is Mode-S code AC72E4?
AC72E4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N901AA.
Where is Mode-S AC72E4 registered?
Mode-S code AC72E4 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 AC72E4 broadcasting right now?
No active broadcast right now. Last signal was 19h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC72E4, octal 53071344, decimal 11,301,604.
What flights does AC72E4 operate?
Mode-S AC72E4 has broadcast 5 distinct callsigns, including AAL1669, AAL2534, AAL1832, AAL1956, AAL2567.