sensors Mode-S transponder
AC6C3C
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N9U · CESSNA 560XL Citation XLS · operated by BCL AVIATION LLC
- Hex
- AC6C3C
- Octal
- 53066074
- Decimal
- 11,299,900
- Country
- US
- Tail
- N9U
- Type
- C56X
- Flights observed
- 30
- Distinct callsigns
- 1
- Country
- US
- Last broadcast
- 15d ago
Last known position
Country allocation
The ICAO 24-bit address AC6C3C 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 1 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| N9U | - | 30 | 2026-07-26 |
Recent flights last 30
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-26 | N9U | IND → SUS | Jul 26, 15:10 UTC | Jul 26, 15:55 UTC | 45m |
| 2026-07-25 | N9U | - | Jul 25, 13:50 UTC | Jul 25, 14:35 UTC | 45m |
| 2026-07-22 | N9U | - | Jul 22, 20:55 UTC | Jul 22, 21:55 UTC | 1h 0m |
| 2026-07-21 | N9U | - | Jul 21, 12:10 UTC | Jul 21, 13:15 UTC | 1h 5m |
| 2026-07-20 | N9U | - | Jul 20, 21:00 UTC | Jul 20, 22:25 UTC | 1h 25m |
| 2026-07-19 | N9U | - | Jul 19, 15:15 UTC | Jul 19, 16:40 UTC | 1h 25m |
| 2026-07-12 | N9U | - | Jul 12, 03:35 UTC | Jul 12, 05:01 UTC | 1h 25m |
| 2026-07-11 | N9U | - | Jul 11, 16:05 UTC | Jul 11, 17:25 UTC | 1h 20m |
| 2026-06-28 | N9U | APC → SUS | Jun 28, 21:45 UTC | Jun 29, 01:10 UTC | 3h 25m |
| 2026-06-25 | N9U | - | Jun 25, 19:34 UTC | Jun 26, 00:39 UTC | 5h 5m |
| 2026-06-14 | N9U | - | Jun 14, 00:05 UTC | Jun 14, 02:15 UTC | 2h 10m |
| 2026-06-13 | N9U | - | Jun 13, 09:55 UTC | Jun 13, 11:35 UTC | 1h 40m |
| 2026-05-21 | N9U | - | May 21, 18:10 UTC | May 21, 21:00 UTC | 2h 50m |
| 2026-05-21 | N9U | - | May 21, 12:40 UTC | May 21, 14:35 UTC | 1h 55m |
| 2026-05-16 | N9U | DOV → SUS | May 16, 23:55 UTC | May 17, 02:10 UTC | 2h 15m |
| 2026-05-16 | N9U | - | May 16, 15:40 UTC | May 16, 16:15 UTC | 35m |
| 2026-05-14 | N9U | - | May 14, 22:00 UTC | May 14, 23:25 UTC | 1h 25m |
| 2026-05-14 | N9U | - | May 14, 18:15 UTC | May 14, 19:30 UTC | 1h 15m |
| 2026-05-12 | N9U | - | May 12, 20:25 UTC | May 12, 21:30 UTC | 1h 5m |
| 2026-05-12 | N9U | - | May 12, 12:35 UTC | May 12, 13:25 UTC | 50m |
| 2026-05-07 | N9U | - | May 7, 05:00 UTC | May 7, 07:00 UTC | 2h 0m |
| 2026-05-06 | N9U | - | May 6, 12:15 UTC | May 6, 13:40 UTC | 1h 25m |
| 2026-05-04 | N9U | - | May 4, 00:10 UTC | May 4, 02:50 UTC | 2h 40m |
| 2026-04-30 | N9U | - | Apr 30, 21:55 UTC | May 1, 00:10 UTC | 2h 15m |
| 2026-04-27 | N9U | - | Apr 27, 17:40 UTC | Apr 27, 20:20 UTC | 2h 40m |
| 2026-04-26 | N9U | - | Apr 26, 04:50 UTC | Apr 26, 06:10 UTC | 1h 20m |
| 2026-04-25 | N9U | - | Apr 25, 15:40 UTC | Apr 25, 17:10 UTC | 1h 30m |
| 2026-04-25 | N9U | - | Apr 25, 12:50 UTC | Apr 25, 15:05 UTC | 2h 15m |
| 2026-04-19 | N9U | - | Apr 19, 15:40 UTC | Apr 19, 16:15 UTC | 35m |
| 2026-04-17 | N9U | - | Apr 17, 22:05 UTC | Apr 17, 23:05 UTC | 1h 0m |
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 N9U page for operator, model, and routing details .