sensors Mode-S transponder

ACAC8C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N9157A · CESSNA 172 Skyhawk · operated by 9K AIR LLC

Hex
ACAC8C
Octal
53126214
Decimal
11,316,364
Country
US
Tail
N9157A
Type
C172
No current signal · last broadcast 20h ago
Flights observed
8
Distinct callsigns
1
Country
US
Last broadcast
20h ago

Last known position

Most recent position reported by Mode-S ACAC8C.

Country allocation

The ICAO 24-bit address ACAC8C 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
N9157A - 8 2026-04-14

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-14 N9157A BFL → BFL Apr 14, 05:15 UTCApr 14, 05:50 UTC35m
2026-04-13 N9157A BFL → BFL Apr 13, 21:15 UTCApr 13, 21:45 UTC30m
2026-04-13 N9157A BFL → BFL Apr 13, 20:30 UTCApr 13, 21:05 UTC35m
2026-04-13 N9157A BFL → BFL Apr 13, 18:35 UTCApr 13, 19:35 UTC1h 0m
2026-04-13 N9157A - Apr 13, 16:15 UTCApr 13, 16:35 UTC20m
2026-04-13 N9157A - Apr 13, 16:10 UTCApr 13, 16:15 UTC5m
2026-04-13 N9157A BFL → BFL Apr 13, 15:10 UTCApr 13, 15:20 UTC10m
2026-04-13 N9157A BFL → BFL Apr 13, 14:10 UTCApr 13, 15:05 UTC55m

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 N9157A page for operator, model, and routing details .

Mode-S ACAC8C frequently asked

What is Mode-S code ACAC8C?
ACAC8C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N9157A.
Where is Mode-S ACAC8C registered?
Mode-S code ACAC8C 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 ACAC8C broadcasting right now?
No active broadcast right now. Last signal was 20h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ACAC8C, octal 53126214, decimal 11,316,364.
What flights does ACAC8C operate?
Mode-S ACAC8C has broadcast 1 distinct callsign, including N9157A.