sensors Mode-S transponder

7C531D

ICAO 24-bit transponder address · allocated to Australia

Currently assigned to VH-QPB · AIRBUS A-330-300 · operated by QANTAS AIRWAYS LIMITED

Hex
7C531D
Octal
37051435
Decimal
8,147,741
Country
AU
Tail
VH-QPB
Type
A333
Photo of VH-QPB
No current signal · last broadcast 13h ago
Flights observed
5
Distinct callsigns
2
Country
AU
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S 7C531D.

Country allocation

The ICAO 24-bit address 7C531D 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 2 distinct

Callsign Airline Flights Last seen
QFA61 Qantas 3 2026-04-14
QFA62 Qantas 2 2026-04-13

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-14 QFA61 BNE → HND Apr 14, 09:15 UTCApr 14, 10:00 UTC45m
2026-04-13 QFA62 NRT → BNE Apr 13, 20:50 UTCApr 13, 21:20 UTC30m
2026-04-13 QFA62 NRT → BNE Apr 13, 13:00 UTCApr 13, 13:40 UTC40m
2026-04-13 QFA61 - Apr 13, 09:25 UTCApr 13, 10:15 UTC50m
2026-04-13 QFA61 - Apr 13, 01:20 UTCApr 13, 01:50 UTC30m

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-QPB page for operator, model, and routing details .

Mode-S 7C531D frequently asked

What is Mode-S code 7C531D?
7C531D is an ICAO 24-bit transponder address. Allocated to Australia. Assigned to VH-QPB.
Where is Mode-S 7C531D registered?
Mode-S code 7C531D is allocated to Australia (AU). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 7C531D broadcasting right now?
No active broadcast right now. Last signal was 13h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 7C531D, octal 37051435, decimal 8,147,741.
What flights does 7C531D operate?
Mode-S 7C531D has broadcast 2 distinct callsigns, including QFA61, QFA62.