sensors Mode-S transponder

4003A7

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to VQ-TKN

Hex
4003A7
Octal
20001647
Decimal
4,195,239
Country
GB
Tail
VQ-TKN
Type
AT45
No current signal · last broadcast 1d ago
Flights observed
6
Distinct callsigns
6
Country
GB
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 4003A7.

Country allocation

The ICAO 24-bit address 4003A7 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 6 distinct

Callsign Airline Flights Last seen
IWY788 - 1 2026-04-13
IWY767 - 1 2026-04-13
IWY743 - 1 2026-04-13
IWY742 Interisland Airways Limited 1 2026-04-13
IWY705 - 1 2026-04-13
IWY2766 - 1 2026-04-13

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 IWY788 - Apr 13, 23:10 UTCApr 13, 23:30 UTC20m
2026-04-13 IWY743 - Apr 13, 20:25 UTCApr 13, 20:50 UTC25m
2026-04-13 IWY742 BGI → SLU Apr 13, 19:00 UTCApr 13, 19:25 UTC25m
2026-04-13 IWY705 - Apr 13, 15:20 UTCApr 13, 15:45 UTC25m
2026-04-13 IWY2766 - Apr 13, 01:30 UTCApr 13, 01:50 UTC20m
2026-04-13 IWY767 - Apr 13, 00:30 UTCApr 13, 00:55 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 VQ-TKN page for operator, model, and routing details .

Mode-S 4003A7 frequently asked

What is Mode-S code 4003A7?
4003A7 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to VQ-TKN.
Where is Mode-S 4003A7 registered?
Mode-S code 4003A7 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 4003A7 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 4003A7, octal 20001647, decimal 4,195,239.
What flights does 4003A7 operate?
Mode-S 4003A7 has broadcast 6 distinct callsigns, including IWY788, IWY767, IWY743, IWY742, IWY705.