sensors Mode-S transponder

AC490C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N891AA · BEECH 90 King Air · operated by AUGUSTA AVIATION INC

Hex
AC490C
Octal
53044414
Decimal
11,290,892
Country
US
Tail
N891AA
Type
BE9L
No current signal · last broadcast 16h ago
Flights observed
7
Distinct callsigns
1
Country
US
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S AC490C.

Country allocation

The ICAO 24-bit address AC490C 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 1 distinct

Callsign Airline Flights Last seen
N891AA - 7 2026-04-14

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-14 N891AA - Apr 14, 06:35 UTCApr 14, 07:10 UTC35m
2026-04-13 N891AA - Apr 13, 17:45 UTCApr 13, 18:20 UTC35m
2026-04-13 N891AA - Apr 13, 16:40 UTCApr 13, 17:15 UTC35m
2026-04-13 N891AA - Apr 13, 13:40 UTCApr 13, 15:20 UTC1h 40m
2026-04-13 N891AA - Apr 13, 12:20 UTCApr 13, 13:00 UTC40m
2026-04-13 N891AA - Apr 13, 11:55 UTCApr 13, 13:00 UTC1h 5m
2026-04-13 N891AA - Apr 13, 11:15 UTCApr 13, 12:15 UTC1h 0m

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 N891AA page for operator, model, and routing details .

Mode-S AC490C frequently asked

What is Mode-S code AC490C?
AC490C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N891AA.
Where is Mode-S AC490C registered?
Mode-S code AC490C 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 AC490C broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC490C, octal 53044414, decimal 11,290,892.
What flights does AC490C operate?
Mode-S AC490C has broadcast 1 distinct callsign, including N891AA.