sensors Mode-S transponder

408121

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-VPIE · AIRBUS A-330-900

Hex
408121
Octal
20100441
Decimal
4,227,361
Country
GB
Tail
G-VPIE
Type
A339
No current signal · last broadcast 12h ago
Flights observed
13
Distinct callsigns
5
Country
GB
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 408121.

Country allocation

The ICAO 24-bit address 408121 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 5 distinct

Callsign Airline Flights Last seen
VIR22Q - 4 2026-04-13
VIR153 Virgin Atlantic Airways 4 2026-04-13
VIR21K Virgin Atlantic Airways 3 2026-04-13
VIR154 Virgin Atlantic Airways 1 2026-04-14
VIR105 - 1 2026-04-14

Recent flights last 13

DateFlightRouteTakeoffLandingDuration
2026-04-14 VIR105 - Apr 14, 10:55 UTCApr 14, 11:05 UTC10m
2026-04-14 VIR154 JFK → LHR Apr 14, 07:15 UTCApr 14, 08:25 UTC1h 10m
2026-04-13 VIR153 LHR → JFK Apr 13, 20:50 UTCApr 13, 23:00 UTC2h 10m
2026-04-13 VIR153 LHR → JFK Apr 13, 16:15 UTCApr 13, 16:45 UTC30m
2026-04-13 VIR153 LHR → JFK Apr 13, 15:50 UTCApr 13, 16:45 UTC55m
2026-04-13 VIR153 LHR → JFK Apr 13, 15:20 UTCApr 13, 16:15 UTC55m
2026-04-13 VIR22Q - Apr 13, 08:50 UTCApr 13, 10:10 UTC1h 20m
2026-04-13 VIR22Q - Apr 13, 04:20 UTCApr 13, 05:35 UTC1h 15m
2026-04-13 VIR22Q - Apr 13, 03:55 UTCApr 13, 05:35 UTC1h 40m
2026-04-13 VIR22Q - Apr 13, 03:15 UTCApr 13, 04:15 UTC1h 0m
2026-04-13 VIR21K LHR → IAD Apr 13, 00:20 UTCApr 13, 01:10 UTC50m
2026-04-12 VIR21K LHR → IAD Apr 12, 23:55 UTCApr 13, 01:10 UTC1h 15m
2026-04-12 VIR21K LHR → IAD Apr 12, 17:20 UTCApr 12, 18:40 UTC1h 20m

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

Mode-S 408121 frequently asked

What is Mode-S code 408121?
408121 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-VPIE.
Where is Mode-S 408121 registered?
Mode-S code 408121 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 408121 broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 408121, octal 20100441, decimal 4,227,361.
What flights does 408121 operate?
Mode-S 408121 has broadcast 5 distinct callsigns, including VIR22Q, VIR153, VIR21K, VIR154, VIR105.