sensors Mode-S transponder

400A99

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-NEWG · BOEING 737-700

Hex
400A99
Octal
20005231
Decimal
4,197,017
Country
GB
Tail
G-NEWG
Type
B737
No current signal · last broadcast 10d ago
Flights observed
26
Distinct callsigns
18
Country
GB
Last broadcast
10d ago

Last known position

Most recent position reported by Mode-S 400A99.

Country allocation

The ICAO 24-bit address 400A99 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 18 distinct

Callsign Airline Flights Last seen
BRO116P - 6 2026-05-24
BRO084P - 2 2026-04-23
BRO081P - 2 2026-04-19
BRO077P - 2 2026-05-20
BRO160P - 1 2026-04-25
BRO160A - 1 2026-04-25
BRO116Z - 1 2026-05-23
BRO116X - 1 2026-05-09
BRO116W - 1 2026-04-25
BRO116A - 1 2026-05-24
BRO084B - 1 2026-04-22
BRO084A - 1 2026-04-21
BRO081S - 1 2026-04-19
BRO081R - 1 2026-04-18
BRO079R - 1 2026-04-12
BRO078U - 1 2026-05-17
BRO078S - 1 2026-05-16
BRO077Y - 1 2026-05-19

Recent flights last 26

DateFlightRouteTakeoffLandingDuration
2026-05-24 BRO116A LTN → NCL May 24, 20:15 UTCMay 24, 21:00 UTC45m
2026-05-24 BRO116P FAB → LTN May 24, 16:55 UTCMay 24, 17:20 UTC25m
2026-05-23 BRO116Z NCL → FAB May 23, 13:40 UTCMay 23, 14:35 UTC55m
2026-05-23 BRO116P - May 23, 10:40 UTCMay 23, 11:25 UTC45m
2026-05-20 BRO077P BOH → STN May 20, 13:00 UTCMay 20, 13:35 UTC35m
2026-05-19 BRO077Y MAN → BOH May 19, 09:35 UTCMay 19, 10:15 UTC40m
2026-05-18 BRO077P - May 18, 15:30 UTCMay 18, 16:00 UTC30m
2026-05-17 BRO078U NCL → STN May 17, 20:30 UTCMay 17, 21:20 UTC50m
2026-05-16 BRO078S - May 16, 15:35 UTCMay 16, 16:20 UTC45m
2026-05-10 BRO116P - May 10, 18:29 UTCMay 10, 19:09 UTC40m
2026-05-10 BRO116P EMA → NCL May 10, 17:30 UTCMay 10, 17:59 UTC30m
2026-05-09 BRO116X NCL → EMA May 9, 14:50 UTCMay 9, 15:25 UTC35m
2026-05-08 BRO116P - May 8, 13:10 UTCMay 8, 13:55 UTC45m
2026-04-26 BRO116P - Apr 26, 13:25 UTCApr 26, 14:15 UTC50m
2026-04-25 BRO116W - Apr 25, 22:10 UTCApr 25, 23:05 UTC55m
2026-04-25 BRO160A - Apr 25, 15:30 UTCApr 25, 16:05 UTC35m
2026-04-25 BRO160P - Apr 25, 12:55 UTCApr 25, 13:30 UTC35m
2026-04-23 BRO084P - Apr 23, 11:40 UTCApr 23, 12:25 UTC45m
2026-04-22 BRO084B BOH → LBA Apr 22, 22:40 UTCApr 22, 23:20 UTC40m
2026-04-21 BRO084A - Apr 21, 17:10 UTCApr 21, 17:55 UTC45m
2026-04-21 BRO084P - Apr 21, 13:40 UTCApr 21, 14:15 UTC35m
2026-04-19 BRO081P - Apr 19, 21:55 UTCApr 19, 22:05 UTC10m
2026-04-19 BRO081S MAN → LTN Apr 19, 20:35 UTCApr 19, 21:00 UTC25m
2026-04-18 BRO081R LTN → MAN Apr 18, 16:20 UTCApr 18, 16:55 UTC35m
2026-04-18 BRO081P - Apr 18, 13:30 UTCApr 18, 13:40 UTC10m
2026-04-12 BRO079R NCL → STN Apr 12, 18:15 UTCApr 12, 19:00 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-NEWG page for operator, model, and routing details .

Mode-S 400A99 frequently asked

What is Mode-S code 400A99?
400A99 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-NEWG.
Where is Mode-S 400A99 registered?
Mode-S code 400A99 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 400A99 broadcasting right now?
No active broadcast right now. Last signal was 10d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 400A99, octal 20005231, decimal 4,197,017.
What flights does 400A99 operate?
Mode-S 400A99 has broadcast 18 distinct callsigns, including BRO116P, BRO084P, BRO081P, BRO077P, BRO160P.