sensors Mode-S transponder
A561FD
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N446MC · BOEING 747-400 · operated by ATLAS AIR INC
- Hex
- A561FD
- Octal
- 51260775
- Decimal
- 10,838,525
- Country
- US
- Tail
- N446MC
- Type
- B744
- Flights observed
- 176
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 4d ago
Last known position
Country allocation
The ICAO 24-bit address A561FD 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 |
|---|---|---|---|
| GTI8117 | - | 16 | 2026-07-13 |
| GTI8560 | - | 15 | 2026-07-09 |
| GTI512 | Atlas Air | 15 | 2026-04-19 |
| GTI8120 | - | 13 | 2026-07-15 |
| GTI8603 | - | 11 | 2026-06-18 |
| GTI8559 | - | 11 | 2026-07-08 |
| GTI8193 | - | 8 | 2026-06-23 |
| GTI8174 | - | 7 | 2026-07-17 |
| GTI812 | - | 7 | 2026-06-13 |
| GTI8243 | Atlas Air | 5 | 2026-06-03 |
| GTI8028 | Atlas Air | 5 | 2026-04-16 |
| GTI8857 | Atlas Air | 3 | 2026-04-23 |
| GTI8824 | Atlas Air | 3 | 2026-05-27 |
| GTI8676 | Atlas Air | 3 | 2026-04-25 |
| GTI8602 | - | 3 | 2026-06-17 |
| GTI8551 | Atlas Air | 3 | 2026-05-11 |
| GTI8242 | Atlas Air | 3 | 2026-06-10 |
| GTI5579 | Atlas Air | 3 | 2026-05-05 |
| GTI518 | Atlas Air | 3 | 2026-05-25 |
| GTI511 | Atlas Air | 3 | 2026-04-19 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-17 | GTI8995 | HHN → PSM | Jul 17, 08:45 UTC | Jul 17, 20:40 UTC | 11h 55m |
| 2026-07-17 | GTI8174 | - | Jul 17, 04:39 UTC | Jul 17, 06:00 UTC | 1h 20m |
| 2026-07-17 | GTI8174 | - | Jul 17, 02:59 UTC | Jul 17, 03:10 UTC | 10m |
| 2026-07-16 | GTI8174 | - | Jul 16, 13:34 UTC | Jul 16, 18:59 UTC | 5h 25m |
| 2026-07-15 | GTI8174 | - | Jul 15, 19:00 UTC | Jul 16, 11:10 UTC | 16h 10m |
| 2026-07-15 | GTI8173 | - | Jul 15, 09:20 UTC | Jul 16, 05:15 UTC | 19h 55m |
| 2026-07-15 | GTI8120 | - | Jul 15, 01:50 UTC | Jul 15, 06:20 UTC | 4h 30m |
| 2026-07-14 | GTI8120 | ICN → ANC | Jul 14, 16:25 UTC | Jul 14, 23:55 UTC | 7h 29m |
| 2026-07-13 | GTI8120 | - | Jul 13, 20:00 UTC | Jul 13, 20:25 UTC | 25m |
| 2026-07-13 | GTI8117 | - | Jul 13, 11:15 UTC | Jul 13, 11:30 UTC | 15m |
| 2026-07-13 | GTI8117 | - | Jul 13, 04:05 UTC | Jul 13, 04:45 UTC | 40m |
| 2026-07-12 | GTI8117 | - | Jul 12, 11:05 UTC | Jul 13, 00:01 UTC | 12h 55m |
| 2026-07-12 | GTI8120 | - | Jul 12, 01:40 UTC | Jul 12, 06:55 UTC | 5h 15m |
| 2026-07-11 | GTI8120 | ICN → ANC | Jul 11, 14:35 UTC | Jul 11, 22:10 UTC | 7h 35m |
| 2026-07-11 | GTI8120 | - | Jul 11, 12:00 UTC | Jul 11, 12:20 UTC | 20m |
| 2026-07-11 | GTI8117 | - | Jul 11, 05:15 UTC | Jul 11, 05:31 UTC | 15m |
| 2026-07-11 | GTI8117 | - | Jul 11, 01:35 UTC | Jul 11, 01:45 UTC | 10m |
| 2026-07-10 | GTI8117 | - | Jul 10, 22:15 UTC | Jul 10, 22:55 UTC | 40m |
| 2026-07-10 | GTI8117 | - | Jul 10, 07:10 UTC | Jul 10, 19:50 UTC | 12h 40m |
| 2026-07-09 | GTI8560 | - | Jul 9, 13:00 UTC | Jul 9, 17:25 UTC | 4h 25m |
| 2026-07-09 | GTI8560 | ICN → ANC | Jul 9, 03:15 UTC | Jul 9, 11:00 UTC | 7h 45m |
| 2026-07-09 | GTI8560 | - | Jul 9, 00:40 UTC | Jul 9, 01:00 UTC | 20m |
| 2026-07-08 | GTI8559 | - | Jul 8, 18:05 UTC | Jul 8, 18:15 UTC | 10m |
| 2026-07-08 | GTI8559 | - | Jul 8, 12:05 UTC | Jul 8, 16:00 UTC | 3h 55m |
| 2026-07-07 | GTI531 | - | Jul 7, 04:35 UTC | Jul 7, 16:35 UTC | 12h 0m |
| 2026-07-06 | GTI8174 | - | Jul 6, 19:15 UTC | Jul 6, 22:30 UTC | 3h 15m |
| 2026-07-06 | GTI8174 | - | Jul 6, 09:30 UTC | Jul 6, 15:35 UTC | 6h 5m |
| 2026-07-05 | GTI8174 | - | Jul 5, 16:00 UTC | Jul 6, 07:35 UTC | 15h 35m |
| 2026-07-05 | GTI8173 | - | Jul 5, 06:05 UTC | Jul 6, 01:45 UTC | 19h 40m |
| 2026-07-04 | GTI8120 | - | Jul 4, 23:00 UTC | Jul 5, 03:30 UTC | 4h 30m |
| 2026-07-04 | GTI8120 | ICN → ANC | Jul 4, 12:55 UTC | Jul 4, 20:20 UTC | 7h 25m |
| 2026-07-04 | GTI8120 | - | Jul 4, 10:15 UTC | Jul 4, 10:40 UTC | 25m |
| 2026-07-04 | GTI8117 | - | Jul 4, 03:45 UTC | Jul 4, 04:05 UTC | 20m |
| 2026-07-03 | GTI8117 | - | Jul 3, 21:05 UTC | Jul 4, 01:00 UTC | 3h 55m |
| 2026-07-02 | GTI8117 | - | Jul 2, 08:00 UTC | Jul 2, 21:20 UTC | 13h 20m |
| 2026-07-01 | GTI8560 | ANC → ORD | Jul 1, 20:50 UTC | Jul 2, 02:35 UTC | 5h 45m |
| 2026-07-01 | GTI8560 | ICN → ANC | Jul 1, 11:20 UTC | Jul 1, 18:35 UTC | 7h 15m |
| 2026-07-01 | GTI8560 | - | Jul 1, 09:10 UTC | Jul 1, 09:30 UTC | 20m |
| 2026-07-01 | GTI8559 | - | Jul 1, 03:00 UTC | Jul 1, 03:20 UTC | 20m |
| 2026-06-30 | GTI8559 | - | Jun 30, 20:15 UTC | Jun 30, 23:55 UTC | 3h 40m |
| 2026-06-30 | GTI8559 | - | Jun 30, 01:09 UTC | Jun 30, 14:10 UTC | 13h 1m |
| 2026-06-27 | GTI8366 | LAX → SYD | Jun 27, 22:29 UTC | Jun 28, 01:25 UTC | 2h 55m |
| 2026-06-26 | GTI8365 | PVG → ANC | Jun 26, 07:55 UTC | Jun 26, 13:34 UTC | 5h 40m |
| 2026-06-25 | GTI8365 | PVG → ANC | Jun 25, 22:29 UTC | Jun 26, 05:44 UTC | 7h 15m |
| 2026-06-24 | GTI8364 | LAX → ICN | Jun 24, 18:20 UTC | Jun 24, 19:00 UTC | 40m |
| 2026-06-24 | GTI8254 | ORD → ICN | Jun 24, 02:34 UTC | Jun 24, 16:05 UTC | 13h 30m |
| 2026-06-23 | GTI8193 | ANC → ORD | Jun 23, 08:04 UTC | Jun 23, 13:19 UTC | 5h 15m |
| 2026-06-22 | GTI8193 | ICN → ANC | Jun 22, 22:15 UTC | Jun 23, 05:45 UTC | 7h 30m |
| 2026-06-22 | GTI8193 | - | Jun 22, 17:25 UTC | Jun 22, 19:19 UTC | 1h 55m |
| 2026-06-22 | GTI8192 | - | Jun 22, 11:44 UTC | Jun 22, 12:25 UTC | 40m |
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 N446MC page for operator, model, and routing details .