sensors Mode-S transponder

4065B4

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-CLGU · Schleicher ASG 29 27-18

Hex
4065B4
Octal
20062664
Decimal
4,220,340
Country
GB
Tail
G-CLGU
Type
GLID
No current signal · last broadcast 8d ago
Flights observed
3
Distinct callsigns
3
Country
GB
Last broadcast
8d ago

Last known position

Most recent position reported by Mode-S 4065B4.

Country allocation

The ICAO 24-bit address 4065B4 falls within the block assigned to United Kingdom (GB) by ICAO Annex 10, Volume III. Every aircraft registered in United Kingdom 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 3 distinct

Callsign Airline Flights Last seen
VIR8Y Virgin Atlantic Airways 1 2026-05-02
VIR20V Virgin Atlantic Airways 1 2026-05-21
VIR10H Virgin Atlantic Airways 1 2026-05-10

Recent flights last 3

DateFlightRouteTakeoffLandingDuration
2026-05-21 VIR20V SFO → LHR May 21, 10:35 UTCMay 21, 10:45 UTC10m
2026-05-10 VIR10H JFK → LHR May 10, 04:55 UTCMay 10, 05:10 UTC15m
2026-05-02 VIR8Y LAX → LHR May 2, 09:00 UTCMay 2, 09:25 UTC25m

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 G-CLGU page for operator, model, and routing details .

Mode-S 4065B4 frequently asked

What is Mode-S code 4065B4?
4065B4 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-CLGU.
Where is Mode-S 4065B4 registered?
Mode-S code 4065B4 is allocated to United Kingdom (GB). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4065B4 broadcasting right now?
No active broadcast right now. Last signal was 8d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4065B4, octal 20062664, decimal 4,220,340.
What flights does 4065B4 operate?
Mode-S 4065B4 has broadcast 3 distinct callsigns, including VIR8Y, VIR20V, VIR10H.