sensors Mode-S transponder

7C66D5

ICAO 24-bit transponder address · allocated to Australia

Currently assigned to VH-ULJ · LEARJET 60

Hex
7C66D5
Octal
37063325
Decimal
8,152,789
Country
AU
Tail
VH-ULJ
Type
LJ60
No current signal · last broadcast 1d ago
Flights observed
5
Distinct callsigns
1
Country
AU
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 7C66D5.

Country allocation

The ICAO 24-bit address 7C66D5 falls within the block assigned to Australia (AU) by ICAO Annex 10, Volume III. Every aircraft registered in Australia 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
VHULJ - 5 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 VHULJ - Apr 13, 17:20 UTCApr 13, 18:50 UTC1h 30m
2026-04-13 VHULJ - Apr 13, 12:20 UTCApr 13, 12:35 UTC15m
2026-04-13 VHULJ - Apr 13, 12:05 UTCApr 13, 12:15 UTC10m
2026-04-13 VHULJ - Apr 13, 07:55 UTCApr 13, 08:15 UTC20m
2026-04-13 VHULJ - Apr 13, 07:35 UTCApr 13, 08:15 UTC40m

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 VH-ULJ page for operator, model, and routing details .

Mode-S 7C66D5 frequently asked

What is Mode-S code 7C66D5?
7C66D5 is an ICAO 24-bit transponder address. Allocated to Australia. Assigned to VH-ULJ.
Where is Mode-S 7C66D5 registered?
Mode-S code 7C66D5 is allocated to Australia (AU). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 7C66D5 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 7C66D5, octal 37063325, decimal 8,152,789.
What flights does 7C66D5 operate?
Mode-S 7C66D5 has broadcast 1 distinct callsign, including VHULJ.