sensors Mode-S transponder

ACA3A3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N913US · AIRBUS A-321 · operated by AMERICAN AIRLINES INC

Hex
ACA3A3
Octal
53121643
Decimal
11,314,083
Country
US
Tail
N913US
Type
A321
No current signal · last broadcast 1d ago
Flights observed
8
Distinct callsigns
4
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S ACA3A3.

Country allocation

The ICAO 24-bit address ACA3A3 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 4 distinct

Callsign Airline Flights Last seen
AAL2305 - 3 2026-04-13
AAL1841 American Airlines 3 2026-04-13
AAL1990 - 1 2026-04-12
AAL1622 - 1 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-13 AAL1622 - Apr 13, 22:05 UTCApr 13, 23:45 UTC1h 40m
2026-04-13 AAL2305 - Apr 13, 19:50 UTCApr 13, 20:35 UTC45m
2026-04-13 AAL2305 - Apr 13, 19:20 UTCApr 13, 20:10 UTC50m
2026-04-13 AAL2305 - Apr 13, 16:40 UTCApr 13, 17:45 UTC1h 5m
2026-04-13 AAL1841 MSY → CLT Apr 13, 13:40 UTCApr 13, 14:55 UTC1h 15m
2026-04-13 AAL1841 MSY → CLT Apr 13, 11:44 UTCApr 13, 15:08 UTC3h 24m
2026-04-13 AAL1841 MSY → CLT Apr 13, 11:29 UTCApr 13, 14:55 UTC3h 26m
2026-04-12 AAL1990 - Apr 12, 17:15 UTCApr 12, 20:00 UTC2h 45m

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 N913US page for operator, model, and routing details .

Mode-S ACA3A3 frequently asked

What is Mode-S code ACA3A3?
ACA3A3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N913US.
Where is Mode-S ACA3A3 registered?
Mode-S code ACA3A3 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 ACA3A3 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ACA3A3, octal 53121643, decimal 11,314,083.
What flights does ACA3A3 operate?
Mode-S ACA3A3 has broadcast 4 distinct callsigns, including AAL2305, AAL1841, AAL1990, AAL1622.