sensors Mode-S transponder
A9C508
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N729AN · BOEING 777-300ER · operated by AMERICAN AIRLINES INC
- Hex
- A9C508
- Octal
- 52342410
- Decimal
- 11,126,024
- Country
- US
- Tail
- N729AN
- Type
- B77W
- Flights observed
- 181
- Distinct callsigns
- 20
- Country
- US
- Last broadcast
- 55m ago
Current position
Country allocation
The ICAO 24-bit address A9C508 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 |
|---|---|---|---|
| AAL730 | - | 13 | 2026-07-06 |
| AAL78 | - | 12 | 2026-07-14 |
| AAL731 | American Airlines | 12 | 2026-07-06 |
| AAL51 | American Airlines | 10 | 2026-07-07 |
| AAL142 | American Airlines | 10 | 2026-07-04 |
| AAL80 | - | 9 | 2026-07-13 |
| AAL72 | - | 9 | 2026-07-10 |
| AAL101 | American Airlines | 9 | 2026-05-09 |
| AAL953 | - | 7 | 2026-07-03 |
| AAL73 | - | 7 | 2026-07-10 |
| AAL20 | - | 7 | 2026-06-23 |
| AAL141 | - | 7 | 2026-07-02 |
| AAL137 | - | 7 | 2026-07-09 |
| AAL735 | American Airlines | 6 | 2026-05-29 |
| AAL954 | - | 5 | 2026-07-04 |
| AAL79 | - | 5 | 2026-07-12 |
| AAL175 | American Airlines | 5 | 2026-06-22 |
| AAL734 | American Airlines | 4 | 2026-05-30 |
| AAL39 | - | 4 | 2026-06-27 |
| AAL216 | - | 4 | 2026-07-07 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-14 | AAL78 | - | Jul 14, 05:00 UTC | Jul 14, 06:00 UTC | 1h 0m |
| 2026-07-13 | AAL81 | LHR → DFW | Jul 13, 16:25 UTC | Jul 14, 01:20 UTC | 8h 55m |
| 2026-07-13 | AAL80 | DFW → LHR | Jul 13, 02:45 UTC | Jul 13, 11:40 UTC | 8h 55m |
| 2026-07-12 | AAL79 | LHR → DFW | Jul 12, 14:01 UTC | Jul 12, 23:50 UTC | 9h 50m |
| 2026-07-12 | AAL136 | - | Jul 12, 01:15 UTC | Jul 12, 11:15 UTC | 10h 0m |
| 2026-07-10 | AAL72 | - | Jul 10, 23:20 UTC | Jul 11, 12:20 UTC | 13h 0m |
| 2026-07-10 | AAL73 | - | Jul 10, 06:20 UTC | Jul 10, 20:20 UTC | 14h 0m |
| 2026-07-09 | AAL137 | - | Jul 9, 16:25 UTC | Jul 10, 02:50 UTC | 10h 25m |
| 2026-07-09 | AAL78 | - | Jul 9, 12:25 UTC | Jul 9, 13:05 UTC | 40m |
| 2026-07-09 | AAL78 | - | Jul 9, 04:30 UTC | Jul 9, 13:05 UTC | 8h 35m |
| 2026-07-09 | AAL78 | DFW → LHR | Jul 9, 04:04 UTC | Jul 9, 12:06 UTC | 8h 2m |
| 2026-07-08 | AAL217 | ATH → DFW | Jul 8, 11:35 UTC | Jul 8, 23:45 UTC | 12h 10m |
| 2026-07-07 | AAL216 | DFW → ATH | Jul 7, 21:44 UTC | Jul 8, 09:06 UTC | 11h 22m |
| 2026-07-07 | AAL216 | - | Jul 7, 21:45 UTC | Jul 8, 06:00 UTC | 8h 15m |
| 2026-07-07 | AAL51 | LHR → DFW | Jul 7, 13:55 UTC | Jul 7, 17:25 UTC | 3h 30m |
| 2026-07-07 | AAL51 | LHR → DFW | Jul 7, 08:25 UTC | Jul 7, 09:40 UTC | 1h 15m |
| 2026-07-06 | AAL730 | - | Jul 6, 22:40 UTC | Jul 7, 05:40 UTC | 7h 0m |
| 2026-07-06 | AAL730 | CLT → LHR | Jul 6, 22:36 UTC | Jul 7, 05:31 UTC | 6h 55m |
| 2026-07-06 | AAL731 | LHR → CLT | Jul 6, 08:30 UTC | Jul 6, 16:20 UTC | 7h 50m |
| 2026-07-05 | AAL730 | - | Jul 5, 22:35 UTC | Jul 6, 05:30 UTC | 6h 55m |
| 2026-07-05 | AAL731 | LHR → CLT | Jul 5, 08:40 UTC | Jul 5, 16:45 UTC | 8h 5m |
| 2026-07-04 | AAL142 | JFK → LHR | Jul 4, 15:13 UTC | Jul 4, 21:13 UTC | 6h 0m |
| 2026-07-04 | AAL142 | JFK → LHR | Jul 4, 15:15 UTC | Jul 4, 20:00 UTC | 4h 45m |
| 2026-07-04 | AAL954 | - | Jul 4, 00:30 UTC | Jul 4, 10:10 UTC | 9h 40m |
| 2026-07-03 | AAL953 | JFK → EZE | Jul 3, 03:51 UTC | Jul 3, 14:00 UTC | 10h 9m |
| 2026-07-03 | AAL953 | - | Jul 3, 03:55 UTC | Jul 3, 08:10 UTC | 4h 15m |
| 2026-07-02 | AAL141 | - | Jul 2, 17:20 UTC | Jul 3, 00:25 UTC | 7h 5m |
| 2026-07-02 | AAL141 | LHR → JFK | Jul 2, 17:17 UTC | Jul 3, 00:25 UTC | 7h 8m |
| 2026-07-02 | AAL80 | - | Jul 2, 04:20 UTC | Jul 2, 12:15 UTC | 7h 55m |
| 2026-07-02 | AAL80 | DFW → LHR | Jul 2, 04:17 UTC | Jul 2, 12:13 UTC | 7h 56m |
| 2026-06-30 | AAL79 | LHR → DFW | Jun 30, 13:55 UTC | Jun 30, 23:25 UTC | 9h 30m |
| 2026-06-30 | AAL38 | - | Jun 30, 00:00 UTC | Jun 30, 08:00 UTC | 8h 1m |
| 2026-06-29 | AAL930 | - | Jun 29, 00:49 UTC | Jun 29, 08:35 UTC | 7h 45m |
| 2026-06-28 | AAL929 | - | Jun 28, 00:50 UTC | Jun 28, 08:29 UTC | 7h 40m |
| 2026-06-27 | AAL39 | - | Jun 27, 11:39 UTC | Jun 27, 11:59 UTC | 20m |
| 2026-06-27 | AAL39 | LHR → MIA | Jun 27, 11:39 UTC | Jun 27, 20:49 UTC | 9h 10m |
| 2026-06-27 | AAL38 | - | Jun 27, 00:10 UTC | Jun 27, 00:44 UTC | 35m |
| 2026-06-27 | AAL38 | MIA → LHR | Jun 27, 00:09 UTC | Jun 27, 07:54 UTC | 7h 45m |
| 2026-06-26 | AAL930 | - | Jun 26, 01:24 UTC | Jun 26, 02:00 UTC | 35m |
| 2026-06-26 | AAL930 | GRU → MIA | Jun 26, 01:15 UTC | Jun 26, 09:13 UTC | 7h 58m |
| 2026-06-25 | AAL929 | - | Jun 25, 01:04 UTC | Jun 25, 08:45 UTC | 7h 40m |
| 2026-06-24 | AAL39 | - | Jun 24, 11:45 UTC | Jun 24, 20:30 UTC | 8h 45m |
| 2026-06-24 | AAL39 | LHR → MIA | Jun 24, 11:41 UTC | Jun 24, 20:25 UTC | 8h 44m |
| 2026-06-23 | AAL20 | DFW → LHR | Jun 23, 23:00 UTC | Jun 24, 07:24 UTC | 8h 25m |
| 2026-06-23 | AAL176 | NRT → DFW | Jun 23, 08:25 UTC | Jun 23, 19:10 UTC | 10h 45m |
| 2026-06-22 | AAL175 | DFW → HND | Jun 22, 17:44 UTC | Jun 23, 06:09 UTC | 12h 25m |
| 2026-06-21 | AAL176 | NRT → DFW | Jun 21, 07:55 UTC | Jun 21, 19:00 UTC | 11h 5m |
| 2026-06-20 | AAL175 | DFW → HND | Jun 20, 16:34 UTC | Jun 21, 05:00 UTC | 12h 25m |
| 2026-06-17 | AAL217 | CLT → AUS | Jun 17, 11:25 UTC | Jun 17, 23:35 UTC | 12h 10m |
| 2026-06-16 | AAL216 | SFO → DFW | Jun 16, 21:20 UTC | Jun 17, 08:00 UTC | 10h 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 N729AN page for operator, model, and routing details .