sensors Mode-S transponder

A5198D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N428CD · operated by CANCELLED/NOT ASSIGNED

Hex
A5198D
Octal
51214615
Decimal
10,819,981
Country
US
Tail
N428CD
No current signal · last broadcast 2d ago
Flights observed
8
Distinct callsigns
1
Country
US
Last broadcast
2d ago

Last known position

Most recent position reported by Mode-S A5198D.

Country allocation

The ICAO 24-bit address A5198D 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
N428CD - 8 2026-05-27

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-05-27 N428CD - May 27, 18:25 UTCMay 27, 19:05 UTC40m
2026-05-25 N428CD - May 25, 18:55 UTCMay 25, 19:44 UTC50m
2026-05-20 N428CD - May 20, 16:00 UTCMay 20, 16:45 UTC45m
2026-05-14 N428CD - May 14, 15:05 UTCMay 14, 15:20 UTC15m
2026-05-07 N428CD - May 7, 19:30 UTCMay 7, 21:15 UTC1h 45m
2026-05-07 N428CD - May 7, 18:40 UTCMay 7, 18:55 UTC15m
2026-05-07 N428CD - May 7, 13:55 UTCMay 7, 14:05 UTC10m
2026-05-06 N428CD - May 6, 18:40 UTCMay 6, 23:35 UTC4h 55m

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 N428CD page for operator, model, and routing details .

Mode-S A5198D frequently asked

What is Mode-S code A5198D?
A5198D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N428CD.
Where is Mode-S A5198D registered?
Mode-S code A5198D 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 A5198D broadcasting right now?
No active broadcast right now. Last signal was 2d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A5198D, octal 51214615, decimal 10,819,981.
What flights does A5198D operate?
Mode-S A5198D has broadcast 1 distinct callsign, including N428CD.