sensors Mode-S transponder

A81CB3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N62128 · CESSNA 172 Skyhawk · operated by CANCELLED/NOT ASSIGNED

Hex
A81CB3
Octal
52016263
Decimal
11,017,395
Country
US
Tail
N62128
Type
C172
No current signal · last broadcast 27d ago
Flights observed
4
Distinct callsigns
2
Country
US
Last broadcast
27d ago

Last known position

Most recent position reported by Mode-S A81CB3.

Country allocation

The ICAO 24-bit address A81CB3 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 2 distinct

Callsign Airline Flights Last seen
N62128 - 3 2026-06-29
5YPPL - 1 2026-05-15

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-06-29 N62128 - Jun 29, 16:10 UTCJun 29, 16:35 UTC25m
2026-06-29 N62128 - Jun 29, 15:30 UTCJun 29, 15:39 UTC10m
2026-05-29 N62128 - May 29, 13:20 UTCMay 29, 13:55 UTC35m
2026-05-15 5YPPL - May 15, 13:10 UTCMay 15, 13:30 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 N62128 page for operator, model, and routing details .

Mode-S A81CB3 frequently asked

What is Mode-S code A81CB3?
A81CB3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N62128.
Where is Mode-S A81CB3 registered?
Mode-S code A81CB3 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 A81CB3 broadcasting right now?
No active broadcast right now. Last signal was 27d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A81CB3, octal 52016263, decimal 11,017,395.
What flights does A81CB3 operate?
Mode-S A81CB3 has broadcast 2 distinct callsigns, including N62128, 5YPPL.