sensors Mode-S transponder

4CC581

ICAO 24-bit transponder address

Currently assigned to TF-IAD · AIRBUS A-321neo

Hex
4CC581
Octal
23142601
Decimal
5,031,297
Tail
TF-IAD
Type
A21N
No current signal · last broadcast 17h ago
Flights observed
5
Distinct callsigns
2
Country
-
Last broadcast
17h ago

Last known position

Most recent position reported by Mode-S 4CC581.

Callsign history 2 distinct

Callsign Airline Flights Last seen
ICE665 Icelandair 3 2026-04-13
ICE664 Icelandair 2 2026-04-14

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-14 ICE664 PDX → KEF Apr 14, 05:40 UTCApr 14, 06:00 UTC20m
2026-04-13 ICE664 PDX → KEF Apr 13, 22:35 UTCApr 13, 23:40 UTC1h 5m
2026-04-13 ICE665 KEF → PDX Apr 13, 00:20 UTCApr 13, 00:50 UTC30m
2026-04-12 ICE665 KEF → PDX Apr 12, 23:55 UTCApr 13, 00:50 UTC55m
2026-04-12 ICE665 KEF → PDX Apr 12, 17:15 UTCApr 12, 20:00 UTC2h 45m

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 TF-IAD page for operator, model, and routing details .

Mode-S 4CC581 frequently asked

What is Mode-S code 4CC581?
4CC581 is an ICAO 24-bit transponder address. Assigned to TF-IAD.
Is 4CC581 broadcasting right now?
No active broadcast right now. Last signal was 17h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4CC581, octal 23142601, decimal 5,031,297.
What flights does 4CC581 operate?
Mode-S 4CC581 has broadcast 2 distinct callsigns, including ICE665, ICE664.