Apparatus

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sensors Mode-S transponder

A2C129

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N277GX · AIRBUS A-321 · operated by WILMINGTON TRUST CO TRUSTEE

Hex
A2C129
Octal
50540451
Decimal
10,666,281
Country
US
Tail
N277GX
Type
A321
Broadcasting now · callsign GXA6138 · 29,000 ft
Flights observed
194
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:15 UTC

Current position

A2C129 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A2C129 falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States 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 20 distinct

Callsign Airline Flights Last seen
GXA6122 Grixona 17 2026-07-26
GXA6121 Grixona 16 2026-07-26
GXA6102 Grixona 9 2026-07-20
GXA6151 Grixona 8 2026-06-16
GXA6152 Grixona 7 2026-06-06
GXA6101 Grixona 7 2026-07-20
GXA6139 - 6 2026-07-07
GXA6127 - 6 2026-06-20
GXA6138 Grixona 5 2026-06-18
GXA6277 Grixona 4 2026-05-13
GXA6275 Grixona 4 2026-05-13
GXA6161 Grixona 4 2026-05-28
GXA6129 - 4 2026-07-05
GXA6128 - 4 2026-07-05
GXA6123 Grixona 4 2026-07-23
GXA6111 - 4 2026-07-03
GXA6108 Grixona 4 2026-07-02
GXA6103 Grixona 4 2026-07-21
GXA6276 Grixona 3 2026-05-13
GXA6228 Grixona 3 2026-05-20

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 GXA6122 HRL → BED Jul 26, 20:15 UTCJul 26, 22:15 UTC2h 0m
2026-07-26 GXA6122 HRL → BED Jul 26, 19:40 UTCJul 26, 19:45 UTC5m
2026-07-26 GXA6122 HRL → BED Jul 26, 18:40 UTCJul 26, 18:50 UTC10m
2026-07-26 GXA6121 HRL → BED Jul 26, 16:30 UTCJul 26, 18:00 UTC1h 30m
2026-07-25 GXA6122 HRL → BED Jul 25, 18:50 UTCJul 25, 21:05 UTC2h 15m
2026-07-25 GXA6122 HRL → BED Jul 25, 17:10 UTCJul 25, 17:20 UTC10m
2026-07-25 GXA6121 HRL → BED Jul 25, 14:55 UTCJul 25, 16:35 UTC1h 40m
2026-07-24 GXA6122 HRL → BED Jul 24, 16:25 UTCJul 24, 18:45 UTC2h 20m
2026-07-24 GXA6121 HRL → BED Jul 24, 12:20 UTCJul 24, 14:40 UTC2h 20m
2026-07-23 GXA6124 MDT → SAT Jul 23, 23:45 UTCJul 24, 02:00 UTC2h 15m
2026-07-23 GXA6123 BED → MDT Jul 23, 20:30 UTCJul 23, 22:50 UTC2h 20m
2026-07-23 KIAH - Jul 23, 15:40 UTCJul 23, 18:00 UTC2h 20m
2026-07-23 KIAH GUA → GUA Jul 23, 15:05 UTCJul 23, 15:10 UTC5m
2026-07-23 GXA6121 HRL → BED Jul 23, 14:35 UTCJul 23, 14:45 UTC10m
2026-07-23 GXA6121 HRL → BED Jul 23, 12:15 UTCJul 23, 14:05 UTC1h 50m
2026-07-22 GXA6123 BED → MDT Jul 22, 19:35 UTCJul 22, 21:15 UTC1h 40m
2026-07-22 GXA6123 BED → MDT Jul 22, 18:45 UTCJul 22, 19:00 UTC15m
2026-07-22 GXA6122 HRL → BED Jul 22, 14:05 UTCJul 22, 16:40 UTC2h 35m
2026-07-22 GXA6121 HRL → BED Jul 22, 12:10 UTCJul 22, 12:35 UTC25m
2026-07-21 GXA6123 BED → MDT Jul 21, 19:45 UTCJul 21, 22:20 UTC2h 35m
2026-07-21 GXA6122 HRL → BED Jul 21, 17:35 UTCJul 21, 17:50 UTC15m
2026-07-21 GXA6122 HRL → BED Jul 21, 15:00 UTCJul 21, 17:05 UTC2h 5m
2026-07-21 GXA6121 HRL → BED Jul 21, 11:55 UTCJul 21, 13:20 UTC1h 25m
2026-07-21 GXA6104 AZA → AEX Jul 21, 06:30 UTCJul 21, 07:25 UTC55m
2026-07-21 GXA6103 AEX → BUF Jul 21, 02:15 UTCJul 21, 04:45 UTC2h 30m
2026-07-20 GXA6102 BUF → BWI Jul 20, 22:45 UTCJul 21, 00:05 UTC1h 19m
2026-07-20 GXA6101 AEX → BUF Jul 20, 20:25 UTCJul 20, 21:30 UTC1h 5m
2026-07-20 GXA6122 - Jul 20, 16:55 UTCJul 20, 18:25 UTC1h 30m
2026-07-20 GXA6121 - Jul 20, 14:35 UTCJul 20, 14:45 UTC10m
2026-07-20 GXA6121 - Jul 20, 12:20 UTCJul 20, 12:55 UTC35m
2026-07-18 GXA6103 AEX → BUF Jul 18, 21:40 UTCJul 18, 23:00 UTC1h 20m
2026-07-18 GXA6102 BUF → BWI Jul 18, 16:00 UTCJul 18, 18:40 UTC2h 40m
2026-07-18 GXA6101 - Jul 18, 12:40 UTCJul 18, 14:10 UTC1h 30m
2026-07-16 GXA153 MIA → CVG Jul 16, 15:49 UTCJul 16, 17:35 UTC1h 45m
2026-07-15 GXA151 - Jul 15, 18:25 UTCJul 15, 18:40 UTC15m
2026-07-12 GXA150 - Jul 12, 00:15 UTCJul 12, 02:01 UTC1h 45m
2026-07-07 GXA6139 - Jul 7, 20:20 UTCJul 7, 22:40 UTC2h 20m
2026-07-07 GXA6168 - Jul 7, 15:40 UTCJul 7, 18:00 UTC2h 20m
2026-07-07 GXA6101 - Jul 7, 13:40 UTCJul 7, 14:10 UTC30m
2026-07-06 GXA6103 - Jul 6, 19:55 UTCJul 6, 21:00 UTC1h 5m
2026-07-06 GXA6102 - Jul 6, 15:35 UTCJul 6, 17:35 UTC2h 0m
2026-07-06 GXA6101 - Jul 6, 12:40 UTCJul 6, 13:30 UTC50m
2026-07-05 GXA6129 - Jul 5, 21:50 UTCJul 5, 23:30 UTC1h 40m
2026-07-05 GXA6129 - Jul 5, 21:05 UTCJul 5, 21:15 UTC10m
2026-07-05 GXA6129 GUA → GUA Jul 5, 20:50 UTCJul 5, 20:55 UTC5m
2026-07-05 GXA6129 GUA → GUA Jul 5, 19:55 UTCJul 5, 20:00 UTC5m
2026-07-05 GXA6128 - Jul 5, 19:20 UTCJul 5, 19:30 UTC10m
2026-07-05 GXA6128 - Jul 5, 17:05 UTCJul 5, 18:45 UTC1h 40m
2026-07-04 GXA6130 - Jul 4, 18:40 UTCJul 4, 21:00 UTC2h 20m
2026-07-04 GXA6130 - Jul 4, 16:35 UTCJul 4, 17:00 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 N277GX page for operator, model, and routing details .

Mode-S A2C129 frequently asked

What is Mode-S code A2C129?
A2C129 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N277GX.
Where is Mode-S A2C129 registered?
Mode-S code A2C129 is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is A2C129 broadcasting right now?
Yes. Mode-S A2C129 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2C129, octal 50540451, decimal 10,666,281.
What flights does A2C129 operate?
Mode-S A2C129 has broadcast 20 distinct callsigns, including GXA6122, GXA6121, GXA6102, GXA6151, GXA6152.