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
- Flights observed
- 103
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 7h ago
Last known position
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 |
|---|---|---|---|
| GTI8905 | Atlas Air | 9 | 2026-04-17 |
| GTI8422 | Atlas Air | 8 | 2026-04-18 |
| GTI8174 | Atlas Air | 6 | 2026-05-20 |
| GTI8998 | Atlas Air | 4 | 2026-05-10 |
| GTI8941 | Atlas Air | 4 | 2026-05-21 |
| GTI8692 | Atlas Air | 4 | 2026-04-14 |
| GTI8102 | Atlas Air | 4 | 2026-05-07 |
| GTI8909 | Atlas Air | 3 | 2026-04-22 |
| GTI8515 | Atlas Air | 3 | 2026-04-27 |
| GTI654 | Atlas Air | 3 | 2026-05-18 |
| GTI512 | Atlas Air | 3 | 2026-05-14 |
| CMB389 | - | 3 | 2026-05-29 |
| GTI9834 | Atlas Air | 2 | 2026-05-01 |
| GTI9789 | Atlas Air | 2 | 2026-05-17 |
| GTI8555 | Atlas Air | 2 | 2026-05-12 |
| GTI8523 | Atlas Air | 2 | 2026-05-04 |
| GTI8421 | Atlas Air | 2 | 2026-04-18 |
| GTI8365 | Atlas Air | 2 | 2026-04-23 |
| GTI825 | Atlas Air | 2 | 2026-05-28 |
| GTI8193 | Atlas Air | 2 | 2026-04-30 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-29 | GTI9901 | CVG → ICN | May 29, 18:05 UTC | May 29, 18:35 UTC | 30m |
| 2026-05-29 | CMB389 | - | May 29, 12:20 UTC | May 29, 14:30 UTC | 2h 10m |
| 2026-05-29 | CMB389 | - | May 29, 07:30 UTC | May 29, 08:45 UTC | 1h 15m |
| 2026-05-28 | CMB389 | - | May 28, 20:10 UTC | May 29, 05:10 UTC | 9h 0m |
| 2026-05-28 | GTI8324 | - | May 28, 14:15 UTC | May 28, 15:45 UTC | 1h 30m |
| 2026-05-28 | GTI825 | ANC → MIA | May 28, 03:45 UTC | May 28, 11:05 UTC | 7h 20m |
| 2026-05-27 | GTI825 | ANC → MIA | May 27, 16:00 UTC | May 28, 01:20 UTC | 9h 20m |
| 2026-05-21 | GTI8941 | ANC → ICN | May 21, 15:30 UTC | May 22, 09:20 UTC | 17h 50m |
| 2026-05-21 | GTI8941 | ANC → ICN | May 21, 13:20 UTC | May 22, 09:20 UTC | 20h 0m |
| 2026-05-21 | GTI8941 | ANC → ICN | May 21, 12:30 UTC | May 22, 09:20 UTC | 20h 50m |
| 2026-05-20 | GTI8941 | ANC → ICN | May 20, 23:50 UTC | May 21, 09:40 UTC | 9h 50m |
| 2026-05-20 | GTI8174 | ANC → NLU | May 20, 19:00 UTC | May 20, 20:30 UTC | 1h 30m |
| 2026-05-20 | GTI8174 | ANC → NLU | May 20, 07:45 UTC | May 20, 12:40 UTC | 4h 55m |
| 2026-05-19 | GTI8174 | ANC → NLU | May 19, 14:30 UTC | May 20, 05:25 UTC | 14h 56m |
| 2026-05-19 | GTI8173 | LAX → PVG | May 19, 04:05 UTC | May 19, 23:40 UTC | 19h 35m |
| 2026-05-18 | GTI9879 | IAH → CVG | May 18, 18:30 UTC | May 18, 23:35 UTC | 5h 5m |
| 2026-05-18 | GTI654 | ANC → ORD | May 18, 12:00 UTC | May 18, 14:40 UTC | 2h 40m |
| 2026-05-18 | GTI654 | ANC → ORD | May 18, 03:50 UTC | May 18, 09:35 UTC | 5h 45m |
| 2026-05-17 | GTI654 | ANC → ORD | May 17, 16:20 UTC | May 18, 02:15 UTC | 9h 55m |
| 2026-05-17 | GTI9789 | MIA → HHN | May 17, 12:45 UTC | May 17, 13:10 UTC | 25m |
| 2026-05-17 | GTI9789 | MIA → HHN | May 17, 02:45 UTC | May 17, 05:45 UTC | 3h 0m |
| 2026-05-16 | CMB395 | - | May 16, 18:35 UTC | May 16, 21:25 UTC | 2h 50m |
| 2026-05-16 | CMB395 | - | May 16, 13:31 UTC | May 16, 15:20 UTC | 1h 50m |
| 2026-05-16 | GTI8574 | MIA → BOG | May 16, 07:45 UTC | May 16, 09:16 UTC | 1h 30m |
| 2026-05-15 | GTI658 | ANC → ORD | May 15, 23:40 UTC | May 16, 05:20 UTC | 5h 40m |
| 2026-05-15 | GTI658 | ANC → ORD | May 15, 13:30 UTC | May 15, 21:30 UTC | 7h 59m |
| 2026-05-14 | GTI9001 | MIA → ORD | May 14, 23:10 UTC | May 15, 11:05 UTC | 11h 55m |
| 2026-05-14 | GTI512 | ANC → ORD | May 14, 16:50 UTC | May 14, 20:20 UTC | 3h 30m |
| 2026-05-14 | GTI512 | ANC → ORD | May 14, 07:20 UTC | May 14, 13:15 UTC | 5h 55m |
| 2026-05-13 | GTI512 | ANC → ORD | May 13, 16:25 UTC | May 14, 05:20 UTC | 12h 55m |
| 2026-05-12 | GTI9927 | ATL → DOV | May 12, 22:25 UTC | May 12, 22:40 UTC | 15m |
| 2026-05-12 | GTI8555 | HHN → BWI | May 12, 05:20 UTC | May 12, 16:35 UTC | 11h 15m |
| 2026-05-11 | GTI8555 | HHN → BWI | May 11, 14:30 UTC | May 11, 22:35 UTC | 8h 5m |
| 2026-05-10 | GTI8204 | IAH → HHN | May 10, 21:00 UTC | May 10, 23:55 UTC | 2h 55m |
| 2026-05-10 | GTI8998 | CHS → HHN | May 10, 09:50 UTC | May 10, 16:55 UTC | 7h 5m |
| 2026-05-09 | GTI8998 | CHS → HHN | May 9, 14:40 UTC | May 10, 07:15 UTC | 16h 35m |
| 2026-05-09 | GTI8998 | CHS → HHN | May 9, 09:30 UTC | May 10, 07:15 UTC | 21h 45m |
| 2026-05-09 | GTI8998 | CHS → HHN | May 9, 08:20 UTC | May 10, 07:15 UTC | 22h 55m |
| 2026-05-08 | GTI8997 | RMS → BWI | May 8, 22:00 UTC | May 9, 06:25 UTC | 8h 25m |
| 2026-05-08 | GTI9271 | MIA → ANC | May 8, 07:24 UTC | May 8, 09:09 UTC | 1h 45m |
| 2026-05-07 | GTI8102 | DFW → ORD | May 7, 01:15 UTC | May 7, 02:05 UTC | 50m |
| 2026-05-06 | GTI8102 | DFW → ORD | May 6, 16:25 UTC | May 6, 22:15 UTC | 5h 49m |
| 2026-05-06 | GTI8102 | DFW → ORD | May 6, 07:45 UTC | May 6, 13:15 UTC | 5h 30m |
| 2026-05-05 | GTI8102 | DFW → ORD | May 5, 16:35 UTC | May 6, 05:55 UTC | 13h 19m |
| 2026-05-04 | GTI8516 | HNL → CVG | May 4, 15:35 UTC | May 5, 05:40 UTC | 14h 6m |
| 2026-05-04 | GTI8523 | ANC → ORD | May 4, 04:50 UTC | May 4, 09:45 UTC | 4h 55m |
| 2026-05-03 | GTI8523 | ANC → ORD | May 3, 18:00 UTC | May 4, 02:45 UTC | 8h 45m |
| 2026-05-03 | GTI9876 | TPE → HAN | May 3, 06:20 UTC | May 3, 14:45 UTC | 8h 25m |
| 2026-05-03 | GTI8576 | ANC → MIA | May 3, 00:35 UTC | May 3, 03:15 UTC | 2h 40m |
| 2026-05-01 | GTI9834 | SUU → CVG | May 1, 18:15 UTC | May 2, 11:40 UTC | 17h 26m |
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 .