sensors Mode-S transponder

A04A01

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N118AX · BEECH 1900 · operated by ALASKA CENTRAL EXPRESS INC

Hex
A04A01
Octal
50045001
Decimal
10,504,705
Country
US
Tail
N118AX
Type
B190
No current signal · last broadcast 1h ago
Flights observed
5
Distinct callsigns
4
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A04A01.

Country allocation

The ICAO 24-bit address A04A01 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
AER32 - 2 2026-06-27
AERT5 - 1 2026-06-28
AER99 - 1 2026-06-26
AER10 - 1 2026-06-27

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-06-28 AERT5 - Jun 28, 00:55 UTCJun 28, 02:14 UTC1h 20m
2026-06-27 AER32 - Jun 27, 01:35 UTCJun 27, 03:25 UTC1h 50m
2026-06-27 AER10 AKN → AKN Jun 27, 00:05 UTCJun 27, 01:04 UTC1h 0m
2026-06-26 AER32 ANC → AKN Jun 26, 22:14 UTCJun 26, 23:19 UTC1h 5m
2026-06-26 AER99 - Jun 26, 17:19 UTCJun 26, 17:40 UTC20m

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 N118AX page for operator, model, and routing details .

Mode-S A04A01 frequently asked

What is Mode-S code A04A01?
A04A01 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N118AX.
Where is Mode-S A04A01 registered?
Mode-S code A04A01 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 A04A01 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A04A01, octal 50045001, decimal 10,504,705.
What flights does A04A01 operate?
Mode-S A04A01 has broadcast 4 distinct callsigns, including AER32, AERT5, AER99, AER10.