sensors Mode-S transponder

AB201A

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N816ER · CESSNA 172 Skyhawk · operated by EMBRY RIDDLE AERONAUTICAL UNIVERSITY INC

Hex
AB201A
Octal
52620032
Decimal
11,214,874
Country
US
Tail
N816ER
Type
C172
Broadcasting now · callsign ERU816 · 5,250 ft
Flights observed
5
Distinct callsigns
1
Country
US
Last broadcast
23h ago

Current position

AB201A is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AB201A 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
ERU816 - 5 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 ERU816 - Apr 13, 23:30 UTCApr 13, 23:40 UTC10m
2026-04-13 ERU816 - Apr 13, 22:45 UTCApr 13, 22:55 UTC10m
2026-04-13 ERU816 - Apr 13, 19:05 UTCApr 13, 19:35 UTC30m
2026-04-13 ERU816 - Apr 13, 18:10 UTCApr 13, 18:35 UTC25m
2026-04-13 ERU816 - Apr 13, 12:35 UTCApr 13, 14:05 UTC1h 30m

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 N816ER page for operator, model, and routing details .

Mode-S AB201A frequently asked

What is Mode-S code AB201A?
AB201A is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N816ER.
Where is Mode-S AB201A registered?
Mode-S code AB201A 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 AB201A broadcasting right now?
Yes. Mode-S AB201A is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AB201A, octal 52620032, decimal 11,214,874.
What flights does AB201A operate?
Mode-S AB201A has broadcast 1 distinct callsign, including ERU816.