sensors Mode-S transponder

ABC668

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N858PU · PIPER PA-28-140/150/160/180 · operated by TRUSTEES OF PURDUE UNIVERSITY, ATTN CHIEF INSPECTOR

Hex
ABC668
Octal
52743150
Decimal
11,257,448
Country
US
Tail
N858PU
Type
P28A
No current signal · last broadcast 1d ago
Flights observed
7
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S ABC668.

Country allocation

The ICAO 24-bit address ABC668 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
PDU58 - 7 2026-04-13

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 PDU58 LAF → LAF Apr 13, 22:15 UTCApr 13, 23:10 UTC55m
2026-04-13 PDU58 LAF → LAF Apr 13, 20:15 UTCApr 13, 21:05 UTC50m
2026-04-13 PDU58 LAF → LAF Apr 13, 18:10 UTCApr 13, 19:15 UTC1h 5m
2026-04-13 PDU58 - Apr 13, 16:30 UTCApr 13, 17:15 UTC45m
2026-04-13 PDU58 - Apr 13, 15:50 UTCApr 13, 17:15 UTC1h 25m
2026-04-13 PDU58 - Apr 13, 15:15 UTCApr 13, 16:05 UTC50m
2026-04-13 PDU58 LAF → LAF Apr 13, 13:05 UTCApr 13, 14:10 UTC1h 5m

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 N858PU page for operator, model, and routing details .

Mode-S ABC668 frequently asked

What is Mode-S code ABC668?
ABC668 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N858PU.
Where is Mode-S ABC668 registered?
Mode-S code ABC668 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 ABC668 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 ABC668, octal 52743150, decimal 11,257,448.
What flights does ABC668 operate?
Mode-S ABC668 has broadcast 1 distinct callsign, including PDU58.