Apparatus

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sensors Mode-S transponder

A523C6

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N430GT · BOEING 747-400 · operated by ATLAS AIR INC

Hex
A523C6
Octal
51221706
Decimal
10,822,598
Country
US
Tail
N430GT
Type
B744
No current signal · last broadcast Jul 26, 21:20 UTC
Flights observed
214
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:20 UTC

Last known position

Most recent position reported by Mode-S A523C6.

Country allocation

The ICAO 24-bit address A523C6 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
GTI8603 - 88 2026-07-07
GTI8602 - 62 2026-07-06
GTI8977 - 13 2026-06-27
GTI8976 - 10 2026-06-26
GTI812 Atlas Air 8 2026-07-22
GTI8025 Atlas Air 6 2026-07-24
GTI612 Atlas Air 5 2026-07-18
GTI8237 - 4 2026-07-19
GTI8439 Atlas Air 2 2026-05-06
GTI8373 Atlas Air 2 2026-07-26
GTI8238 - 2 2026-07-19
GTI9377 Atlas Air 1 2026-05-06
GTI9371 Atlas Air 1 2026-07-19
GTI9142 Atlas Air 1 2026-07-17
GTI9031 Atlas Air 1 2026-05-01
GTI8601 - 1 2026-07-07
GTI8421 Atlas Air 1 2026-07-20
GTI8192 - 1 2026-07-14
GTI8138 Atlas Air 1 2026-07-26
GTI8137 Atlas Air 1 2026-07-25

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 GTI8373 HKG → ANC Jul 26, 20:35 UTCJul 26, 21:10 UTC35m
2026-07-26 GTI8373 HKG → ANC Jul 26, 19:40 UTCJul 26, 19:50 UTC10m
2026-07-26 GTI8138 DEL → HAN Jul 26, 12:40 UTCJul 26, 15:45 UTC3h 5m
2026-07-25 GTI8137 HKG → DEL Jul 25, 10:55 UTCJul 25, 16:30 UTC5h 35m
2026-07-24 GTI8025 ANC → MEX Jul 24, 22:40 UTCJul 24, 23:05 UTC25m
2026-07-24 GTI8025 ANC → MEX Jul 24, 06:45 UTCJul 24, 20:45 UTC14h 0m
2026-07-23 GTI8025 ANC → MEX Jul 23, 22:10 UTCJul 24, 03:20 UTC5h 10m
2026-07-23 GTI8025 ANC → MEX Jul 23, 19:55 UTCJul 23, 20:30 UTC35m
2026-07-23 GTI8025 ANC → MEX Jul 23, 12:30 UTCJul 23, 19:10 UTC6h 40m
2026-07-23 GTI8025 ANC → MEX Jul 23, 04:30 UTCJul 23, 09:10 UTC4h 40m
2026-07-22 GTI812 PVG → ANC Jul 22, 19:50 UTCJul 23, 00:30 UTC4h 40m
2026-07-22 GTI812 PVG → ANC Jul 22, 10:20 UTCJul 22, 13:50 UTC3h 30m
2026-07-21 GTI812 PVG → ANC Jul 21, 16:35 UTCJul 22, 05:25 UTC12h 50m
2026-07-20 GTI8421 HHN → PSM Jul 20, 09:05 UTCJul 20, 23:05 UTC14h 0m
2026-07-19 GTI8238 FRA → ORD Jul 19, 19:50 UTCJul 20, 04:20 UTC8h 30m
2026-07-19 GTI8237 ORD → FRA Jul 19, 08:55 UTCJul 19, 16:45 UTC7h 50m
2026-07-19 GTI9371 ORD → ICN Jul 19, 01:20 UTCJul 19, 03:55 UTC2h 35m
2026-07-18 GTI612 HSV → MIA Jul 18, 19:45 UTCJul 18, 21:35 UTC1h 50m
2026-07-18 GTI612 HSV → MIA Jul 18, 11:25 UTCJul 18, 17:35 UTC6h 10m
2026-07-17 GTI612 HSV → MIA Jul 17, 23:45 UTCJul 18, 09:20 UTC9h 36m
2026-07-17 GTI612 HSV → MIA Jul 17, 19:20 UTCJul 17, 19:55 UTC35m
2026-07-17 GTI612 HSV → MIA Jul 17, 18:25 UTCJul 17, 18:34 UTC10m
2026-07-17 GTI9142 SIN → HKG Jul 17, 06:05 UTCJul 17, 15:29 UTC9h 25m
2026-07-16 CMB448 - Jul 16, 05:25 UTCJul 16, 13:30 UTC8h 5m
2026-07-16 GTI812 YYZ → DOV Jul 16, 00:10 UTCJul 16, 01:25 UTC1h 15m
2026-07-15 GTI812 - Jul 15, 15:20 UTCJul 15, 20:30 UTC5h 10m
2026-07-14 GTI812 ICN → ANC Jul 14, 21:20 UTCJul 15, 12:10 UTC14h 49m
2026-07-14 GTI8192 ORD → ICN Jul 14, 05:25 UTCJul 14, 18:50 UTC13h 25m
2026-07-13 GTI8238 FRA → ORD Jul 13, 17:40 UTCJul 14, 01:55 UTC8h 15m
2026-07-13 GTI8237 - Jul 13, 13:35 UTCJul 13, 14:05 UTC30m
2026-07-13 GTI8237 - Jul 13, 06:05 UTCJul 13, 13:30 UTC7h 25m
2026-07-12 GTI8237 - Jul 12, 23:50 UTCJul 13, 02:45 UTC2h 55m
2026-07-08 GTI072 - Jul 8, 18:10 UTCJul 8, 18:40 UTC30m
2026-07-08 GTI071 - Jul 8, 09:10 UTCJul 8, 10:45 UTC1h 35m
2026-07-07 GTI8601 JFK → MIA Jul 7, 16:30 UTCJul 7, 18:50 UTC2h 20m
2026-07-07 GTI8603 ANC → JFK Jul 7, 08:05 UTCJul 7, 14:10 UTC6h 5m
2026-07-06 GTI8603 - Jul 6, 15:05 UTCJul 7, 05:50 UTC14h 45m
2026-07-06 GTI8603 - Jul 6, 09:35 UTCJul 7, 05:50 UTC20h 15m
2026-07-06 GTI8602 - Jul 6, 08:55 UTCJul 7, 05:50 UTC20h 55m
2026-07-06 GTI8602 JFK → ANC Jul 6, 00:00 UTCJul 6, 06:35 UTC6h 35m
2026-07-05 GTI8603 - Jul 5, 09:10 UTCJul 5, 15:35 UTC6h 25m
2026-07-04 GTI8603 - Jul 4, 11:50 UTCJul 5, 07:05 UTC19h 15m
2026-07-04 GTI8603 ANC → ANC Jul 4, 10:40 UTCJul 5, 07:05 UTC20h 25m
2026-07-04 GTI8602 JFK → ANC Jul 4, 01:25 UTCJul 4, 08:10 UTC6h 45m
2026-07-02 GTI8603 ANC → JFK Jul 2, 12:00 UTCJul 2, 18:25 UTC6h 25m
2026-07-01 GTI8603 - Jul 1, 17:10 UTCJul 2, 08:40 UTC15h 30m
2026-07-01 GTI8603 - Jul 1, 11:35 UTCJul 2, 08:40 UTC21h 5m
2026-07-01 GTI8603 ANC → ANC Jul 1, 11:05 UTCJul 2, 08:40 UTC21h 35m
2026-07-01 GTI8602 - Jul 1, 02:10 UTCJul 1, 08:50 UTC6h 40m
2026-06-30 GTI8603 ANC → JFK Jun 30, 13:45 UTCJun 30, 20:30 UTC6h 45m

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 N430GT page for operator, model, and routing details .

Mode-S A523C6 frequently asked

What is Mode-S code A523C6?
A523C6 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N430GT.
Where is Mode-S A523C6 registered?
Mode-S code A523C6 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 A523C6 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:20 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A523C6, octal 51221706, decimal 10,822,598.
What flights does A523C6 operate?
Mode-S A523C6 has broadcast 20 distinct callsigns, including GTI8603, GTI8602, GTI8977, GTI8976, GTI812.