sensors Mode-S transponder

A13521

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N177VZ · CESSNA T182 Turbo Skylane · operated by VAN BORTEL AIRCRAFT INC

Hex
A13521
Octal
50232441
Decimal
10,564,897
Country
US
Tail
N177VZ
Type
C82S
No current signal · last broadcast 1d ago
Flights observed
9
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A13521.

Country allocation

The ICAO 24-bit address A13521 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
N177VZ - 9 2026-04-16

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-04-16 N177VZ - Apr 16, 20:10 UTCApr 16, 21:05 UTC55m
2026-04-16 N177VZ - Apr 16, 19:15 UTCApr 16, 19:25 UTC10m
2026-04-16 N177VZ - Apr 16, 18:50 UTCApr 16, 19:10 UTC20m
2026-04-16 N177VZ - Apr 16, 17:15 UTCApr 16, 17:40 UTC25m
2026-04-16 N177VZ - Apr 16, 15:20 UTCApr 16, 16:25 UTC1h 5m
2026-04-15 N177VZ - Apr 15, 19:05 UTCApr 15, 19:25 UTC20m
2026-04-15 N177VZ - Apr 15, 17:40 UTCApr 15, 18:30 UTC50m
2026-04-14 N177VZ - Apr 14, 19:05 UTCApr 14, 20:05 UTC1h 0m
2026-04-14 N177VZ - Apr 14, 15:05 UTCApr 14, 16:45 UTC1h 40m

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 N177VZ page for operator, model, and routing details .

Mode-S A13521 frequently asked

What is Mode-S code A13521?
A13521 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N177VZ.
Where is Mode-S A13521 registered?
Mode-S code A13521 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 A13521 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 A13521, octal 50232441, decimal 10,564,897.
What flights does A13521 operate?
Mode-S A13521 has broadcast 1 distinct callsign, including N177VZ.