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sensors Mode-S transponder

402991

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-GYAV · CESSNA 172 Skyhawk

Hex
402991
Octal
20024621
Decimal
4,204,945
Country
GB
Tail
G-GYAV
Type
C172
No current signal · last broadcast Jul 24, 20:05 UTC
Flights observed
55
Distinct callsigns
1
Country
GB
Last broadcast
Jul 24, 20:05 UTC

Last known position

Most recent position reported by Mode-S 402991.

Country allocation

The ICAO 24-bit address 402991 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 1 distinct

Callsign Airline Flights Last seen
GGYAV - 55 2026-07-24

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-24 GGYAV - Jul 24, 19:00 UTCJul 24, 20:05 UTC1h 5m
2026-07-24 GGYAV - Jul 24, 15:05 UTCJul 24, 15:30 UTC25m
2026-07-24 GGYAV - Jul 24, 13:00 UTCJul 24, 13:40 UTC40m
2026-07-22 GGYAV - Jul 22, 14:10 UTCJul 22, 14:30 UTC20m
2026-07-22 GGYAV - Jul 22, 12:05 UTCJul 22, 12:45 UTC40m
2026-07-19 GGYAV - Jul 19, 12:30 UTCJul 19, 12:55 UTC25m
2026-07-19 GGYAV - Jul 19, 10:10 UTCJul 19, 11:10 UTC1h 0m
2026-07-18 GGYAV - Jul 18, 11:05 UTCJul 18, 11:30 UTC25m
2026-07-18 GGYAV - Jul 18, 09:00 UTCJul 18, 09:40 UTC40m
2026-07-14 GGYAV - Jul 14, 11:55 UTCJul 14, 12:20 UTC25m
2026-07-14 GGYAV - Jul 14, 10:20 UTCJul 14, 10:45 UTC25m
2026-07-08 GGYAV - Jul 8, 15:20 UTCJul 8, 15:45 UTC25m
2026-07-08 GGYAV - Jul 8, 13:40 UTCJul 8, 14:20 UTC40m
2026-07-03 GGYAV - Jul 3, 09:30 UTCJul 3, 10:00 UTC30m
2026-06-29 GGYAV LPL → LPL Jun 29, 18:39 UTCJun 29, 19:24 UTC45m
2026-06-29 GGYAV - Jun 29, 12:45 UTCJun 29, 14:29 UTC1h 45m
2026-06-29 GGYAV - Jun 29, 10:40 UTCJun 29, 10:55 UTC15m
2026-06-28 GGYAV - Jun 28, 18:05 UTCJun 28, 19:09 UTC1h 5m
2026-06-28 GGYAV - Jun 28, 11:45 UTCJun 28, 13:10 UTC1h 25m
2026-06-24 GGYAV - Jun 24, 15:24 UTCJun 24, 17:29 UTC2h 5m
2026-06-24 GGYAV - Jun 24, 12:04 UTCJun 24, 13:34 UTC1h 30m
2026-06-24 GGYAV - Jun 24, 09:34 UTCJun 24, 11:05 UTC1h 30m
2026-06-21 GGYAV - Jun 21, 08:10 UTCJun 21, 09:40 UTC1h 30m
2026-06-19 GGYAV - Jun 19, 09:30 UTCJun 19, 11:39 UTC2h 10m
2026-06-15 GGYAV - Jun 15, 13:54 UTCJun 15, 14:24 UTC30m
2026-06-15 GGYAV - Jun 15, 11:54 UTCJun 15, 12:45 UTC50m
2026-06-14 GGYAV - Jun 14, 12:55 UTCJun 14, 13:20 UTC25m
2026-06-14 GGYAV - Jun 14, 10:30 UTCJun 14, 11:05 UTC35m
2026-05-30 GGYAV - May 30, 16:15 UTCMay 30, 16:55 UTC40m
2026-05-30 GGYAV - May 30, 14:35 UTCMay 30, 15:00 UTC25m
2026-05-30 GGYAV - May 30, 12:20 UTCMay 30, 12:50 UTC30m
2026-05-29 GGYAV - May 29, 14:40 UTCMay 29, 15:20 UTC40m
2026-05-29 GGYAV - May 29, 12:35 UTCMay 29, 13:15 UTC40m
2026-05-28 GGYAV - May 28, 15:20 UTCMay 28, 15:55 UTC35m
2026-05-28 GGYAV - May 28, 11:35 UTCMay 28, 12:20 UTC45m
2026-05-27 GGYAV - May 27, 13:30 UTCMay 27, 14:15 UTC45m
2026-05-25 GGYAV - May 25, 12:05 UTCMay 25, 12:45 UTC40m
2026-05-23 GGYAV - May 23, 12:35 UTCMay 23, 14:05 UTC1h 30m
2026-05-23 GGYAV - May 23, 09:15 UTCMay 23, 11:00 UTC1h 45m
2026-05-22 GGYAV - May 22, 16:40 UTCMay 22, 17:30 UTC50m
2026-04-25 GGYAV - Apr 25, 13:40 UTCApr 25, 14:15 UTC35m
2026-04-25 GGYAV - Apr 25, 11:05 UTCApr 25, 11:25 UTC20m
2026-04-23 GGYAV - Apr 23, 15:20 UTCApr 23, 15:30 UTC10m
2026-04-23 GGYAV - Apr 23, 13:10 UTCApr 23, 13:45 UTC35m
2026-04-22 GGYAV - Apr 22, 14:50 UTCApr 22, 15:25 UTC35m
2026-04-22 GGYAV - Apr 22, 12:45 UTCApr 22, 13:25 UTC40m
2026-04-21 GGYAV - Apr 21, 13:10 UTCApr 21, 13:35 UTC25m
2026-04-21 GGYAV - Apr 21, 11:40 UTCApr 21, 11:55 UTC15m
2026-04-21 GGYAV - Apr 21, 10:15 UTCApr 21, 11:05 UTC50m
2026-04-19 GGYAV - Apr 19, 10:30 UTCApr 19, 11:15 UTC45m

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

Mode-S 402991 frequently asked

What is Mode-S code 402991?
402991 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-GYAV.
Where is Mode-S 402991 registered?
Mode-S code 402991 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 402991 broadcasting right now?
No active broadcast right now. Last signal was Jul 24, 20:05 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 402991, octal 20024621, decimal 4,204,945.
What flights does 402991 operate?
Mode-S 402991 has broadcast 1 distinct callsign, including GGYAV.