Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A5277D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N431GT · operated by ATLAS AIR INC

Hex
A5277D
Octal
51223575
Decimal
10,823,549
Country
US
Tail
N431GT
Type
B744
No current signal · last broadcast 4h ago
Flights observed
190
Distinct callsigns
20
Country
US
Last broadcast
4h ago

Last known position

Most recent position reported by Mode-S A5277D.

Country allocation

The ICAO 24-bit address A5277D 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
GTI8174 - 14 2026-06-17
GTI8998 - 13 2026-07-07
GTI8422 - 12 2026-07-13
GTI8905 Atlas Air 9 2026-04-17
GTI8997 - 7 2026-07-06
GTI8692 - 7 2026-06-23
GTI8173 Atlas Air 7 2026-06-16
GTI512 Atlas Air 7 2026-06-03
GTI8941 Atlas Air 4 2026-05-21
GTI8816 Atlas Air 4 2026-06-20
GTI8365 Atlas Air 4 2026-06-04
GTI8102 Atlas Air 4 2026-05-07
GTI8909 Atlas Air 3 2026-04-22
GTI8824 - 3 2026-07-08
GTI8815 - 3 2026-06-18
GTI8704 Atlas Air 3 2026-05-30
GTI8676 Atlas Air 3 2026-06-14
GTI8515 Atlas Air 3 2026-04-27
GTI654 Atlas Air 3 2026-05-18
CMB389 - 3 2026-05-29

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 GTI8917 - Jul 14, 04:15 UTCJul 14, 05:00 UTC45m
2026-07-13 GTI8917 - Jul 13, 17:35 UTCJul 13, 22:10 UTC4h 35m
2026-07-13 GTI8422 - Jul 13, 06:01 UTCJul 13, 13:25 UTC7h 25m
2026-07-12 GTI8422 ICN → ANC Jul 12, 13:30 UTCJul 13, 03:10 UTC13h 40m
2026-07-11 GTI8059 - Jul 11, 17:15 UTCJul 11, 17:30 UTC15m
2026-07-11 GTI8059 - Jul 11, 06:50 UTCJul 11, 16:25 UTC9h 35m
2026-07-09 CMB545 - Jul 9, 16:55 UTCJul 10, 00:00 UTC7h 5m
2026-07-08 GTI8824 - Jul 8, 19:15 UTCJul 9, 03:10 UTC7h 55m
2026-07-08 GTI8824 - Jul 8, 04:45 UTCJul 8, 12:00 UTC7h 15m
2026-07-07 GTI8824 - Jul 7, 23:20 UTCJul 8, 01:30 UTC2h 10m
2026-07-07 GTI8998 - Jul 7, 12:25 UTCJul 7, 19:55 UTC7h 30m
2026-07-06 GTI8998 - Jul 6, 17:10 UTCJul 7, 09:45 UTC16h 35m
2026-07-06 GTI8998 - Jul 6, 11:20 UTCJul 7, 09:45 UTC22h 25m
2026-07-06 GTI8997 - Jul 6, 10:40 UTCJul 7, 09:15 UTC22h 35m
2026-07-06 GTI8997 - Jul 6, 00:35 UTCJul 6, 08:45 UTC8h 10m
2026-07-05 GTI8998 - Jul 5, 12:20 UTCJul 5, 19:45 UTC7h 25m
2026-07-04 GTI8998 - Jul 4, 16:50 UTCJul 5, 09:55 UTC17h 5m
2026-07-04 GTI8998 - Jul 4, 11:20 UTCJul 5, 09:55 UTC22h 35m
2026-07-04 GTI8997 - Jul 4, 11:10 UTCJul 5, 09:15 UTC22h 5m
2026-07-01 GTI8997 MIA → ANC Jul 1, 22:35 UTCJul 2, 06:20 UTC7h 45m
2026-07-01 GTI8998 ANC → MIA Jul 1, 10:25 UTCJul 1, 17:45 UTC7h 20m
2026-06-30 GTI8998 - Jun 30, 14:00 UTCJul 1, 07:30 UTC17h 30m
2026-06-30 GTI8998 - Jun 30, 09:20 UTCJul 1, 07:30 UTC22h 10m
2026-06-30 GTI8997 - Jun 30, 08:10 UTCJul 1, 07:15 UTC23h 5m
2026-06-29 GTI8997 - Jun 29, 22:15 UTCJun 30, 06:20 UTC8h 5m
2026-06-28 GTI8840 LGG → ZAZ Jun 28, 21:50 UTCJun 28, 23:39 UTC1h 50m
2026-06-28 GTI8840 LGG → ZAZ Jun 28, 16:05 UTCJun 28, 16:14 UTC10m
2026-06-28 GTI8838 MIA → LGG Jun 28, 09:45 UTCJun 28, 10:15 UTC30m
2026-06-27 GTI8838 MIA → LGG Jun 27, 23:10 UTCJun 28, 07:14 UTC8h 5m
2026-06-26 GTI8422 ANC → MIA Jun 26, 21:15 UTCJun 27, 05:15 UTC8h 0m
2026-06-26 GTI8422 - Jun 26, 06:35 UTCJun 26, 19:00 UTC12h 25m
2026-06-24 GTI8439 - Jun 24, 19:29 UTCJun 25, 05:09 UTC9h 40m
2026-06-24 GTI8439 - Jun 24, 12:20 UTCJun 24, 17:25 UTC5h 5m
2026-06-23 GTI8692 - Jun 23, 03:29 UTCJun 23, 18:34 UTC15h 5m
2026-06-22 GTI8692 - Jun 22, 14:55 UTCJun 22, 23:35 UTC8h 40m
2026-06-22 GTI8692 - Jun 22, 14:10 UTCJun 22, 14:24 UTC15m
2026-06-21 GTI8537 HNL → HKG Jun 21, 18:44 UTCJun 22, 05:15 UTC10h 30m
2026-06-21 GTI8537 - Jun 21, 10:44 UTCJun 21, 15:44 UTC5h 0m
2026-06-20 GTI8816 SUU → LAX Jun 20, 05:14 UTCJun 20, 06:24 UTC1h 10m
2026-06-19 GTI8816 SUU → LAX Jun 19, 21:34 UTCJun 20, 01:29 UTC3h 55m
2026-06-19 GTI8816 SUU → LAX Jun 19, 11:45 UTCJun 19, 18:30 UTC6h 45m
2026-06-19 GTI8816 SUU → LAX Jun 19, 05:54 UTCJun 19, 07:29 UTC1h 35m
2026-06-18 GTI8815 - Jun 18, 11:00 UTCJun 19, 02:04 UTC15h 4m
2026-06-18 GTI8815 - Jun 18, 02:50 UTCJun 18, 07:40 UTC4h 50m
2026-06-17 GTI8815 - Jun 17, 17:30 UTCJun 17, 21:10 UTC3h 40m
2026-06-17 GTI8174 - Jun 17, 07:45 UTCJun 17, 13:30 UTC5h 45m
2026-06-16 GTI8174 - Jun 16, 14:05 UTCJun 17, 05:10 UTC15h 6m
2026-06-16 GTI8173 LAX → PVG Jun 16, 04:05 UTCJun 16, 23:30 UTC19h 26m
2026-06-15 GTI8675 LAX → ICN Jun 15, 13:25 UTCJun 15, 18:40 UTC5h 15m
2026-06-15 GTI8540 ICN → MCO Jun 15, 01:35 UTCJun 15, 09:54 UTC8h 20m

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 N431GT page for operator, model, and routing details .

Mode-S A5277D frequently asked

What is Mode-S code A5277D?
A5277D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N431GT.
Where is Mode-S A5277D registered?
Mode-S code A5277D 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 A5277D broadcasting right now?
No active broadcast right now. Last signal was 4h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A5277D, octal 51223575, decimal 10,823,549.
What flights does A5277D operate?
Mode-S A5277D has broadcast 20 distinct callsigns, including GTI8174, GTI8998, GTI8422, GTI8905, GTI8997.