sensors Mode-S transponder
A87453
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N644CK · LEARJET 35 · operated by KALITTA CHARTERS LLC
- Hex
- A87453
- Octal
- 52072123
- Decimal
- 11,039,827
- Country
- US
- Tail
- N644CK
- Type
- LJ35
- Flights observed
- 73
- Distinct callsigns
- 10
- Country
- US
- Last broadcast
- 1d ago
Last known position
Country allocation
The ICAO 24-bit address A87453 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 10 distinct
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-26 | USC240 | - | Jul 26, 22:20 UTC | Jul 26, 22:45 UTC | 25m |
| 2026-07-26 | USC240 | - | Jul 26, 20:25 UTC | Jul 26, 21:35 UTC | 1h 10m |
| 2026-07-26 | USC240 | - | Jul 26, 17:50 UTC | Jul 26, 19:40 UTC | 1h 50m |
| 2026-07-21 | USC270 | - | Jul 21, 06:35 UTC | Jul 21, 08:20 UTC | 1h 45m |
| 2026-07-21 | USC270 | OAK → APA | Jul 21, 01:15 UTC | Jul 21, 03:30 UTC | 2h 15m |
| 2026-07-20 | USC102 | - | Jul 20, 01:05 UTC | Jul 20, 01:55 UTC | 50m |
| 2026-07-19 | USC102 | - | Jul 19, 23:40 UTC | Jul 20, 00:40 UTC | 1h 0m |
| 2026-07-19 | USC102 | - | Jul 19, 20:10 UTC | Jul 19, 22:15 UTC | 2h 5m |
| 2026-07-19 | USC102 | BED → ADS | Jul 19, 15:50 UTC | Jul 19, 19:20 UTC | 3h 30m |
| 2026-07-19 | USC102 | - | Jul 19, 02:55 UTC | Jul 19, 04:20 UTC | 1h 25m |
| 2026-07-12 | USC242 | - | Jul 12, 13:40 UTC | Jul 12, 15:05 UTC | 1h 25m |
| 2026-07-11 | USC102 | - | Jul 11, 22:30 UTC | Jul 12, 00:30 UTC | 2h 0m |
| 2026-07-07 | USC270 | - | Jul 7, 04:30 UTC | Jul 7, 06:10 UTC | 1h 40m |
| 2026-07-07 | USC240 | BUR → APA | Jul 7, 01:20 UTC | Jul 7, 03:10 UTC | 1h 50m |
| 2026-07-06 | USC240 | - | Jul 6, 06:10 UTC | Jul 6, 07:00 UTC | 50m |
| 2026-07-06 | USC240 | PDX → OAK | Jul 6, 04:10 UTC | Jul 6, 05:40 UTC | 1h 30m |
| 2026-07-06 | USC240 | - | Jul 6, 01:55 UTC | Jul 6, 03:10 UTC | 1h 15m |
| 2026-07-05 | USC240 | - | Jul 5, 23:55 UTC | Jul 6, 01:10 UTC | 1h 15m |
| 2026-07-05 | USC240 | - | Jul 5, 22:15 UTC | Jul 5, 22:45 UTC | 30m |
| 2026-07-05 | USC240 | SUS → APA | Jul 5, 18:10 UTC | Jul 5, 20:10 UTC | 2h 0m |
| 2026-06-30 | USC31 | - | Jun 30, 04:15 UTC | Jun 30, 05:00 UTC | 45m |
| 2026-06-29 | USC31 | - | Jun 29, 23:54 UTC | Jun 30, 03:30 UTC | 3h 36m |
| 2026-06-29 | USC31 | OAK → SDM | Jun 29, 21:14 UTC | Jun 29, 22:19 UTC | 1h 5m |
| 2026-06-28 | USC102 | - | Jun 28, 23:50 UTC | Jun 29, 00:44 UTC | 55m |
| 2026-06-28 | USC102 | PHX → BUR | Jun 28, 22:20 UTC | Jun 28, 23:29 UTC | 1h 10m |
| 2026-06-28 | USC102 | - | Jun 28, 19:40 UTC | Jun 28, 21:50 UTC | 2h 10m |
| 2026-06-28 | USC102 | BED → ADS | Jun 28, 15:20 UTC | Jun 28, 18:59 UTC | 3h 40m |
| 2026-06-27 | USC102 | - | Jun 27, 22:29 UTC | Jun 28, 00:35 UTC | 2h 5m |
| 2026-06-17 | USC270 | - | Jun 17, 07:30 UTC | Jun 17, 08:35 UTC | 1h 5m |
| 2026-06-15 | USC55 | - | Jun 15, 23:54 UTC | Jun 16, 01:40 UTC | 1h 45m |
| 2026-06-14 | USC101 | - | Jun 14, 19:40 UTC | Jun 14, 21:05 UTC | 1h 25m |
| 2026-06-14 | USC101 | - | Jun 14, 18:45 UTC | Jun 14, 19:25 UTC | 40m |
| 2026-06-14 | USC101 | - | Jun 14, 16:15 UTC | Jun 14, 18:05 UTC | 1h 50m |
| 2026-06-13 | USC102 | - | Jun 13, 22:10 UTC | Jun 14, 00:15 UTC | 2h 5m |
| 2026-06-10 | USC31 | RST → SUS | Jun 10, 13:05 UTC | Jun 10, 14:05 UTC | 1h 0m |
| 2026-06-10 | USC31 | - | Jun 10, 10:15 UTC | Jun 10, 12:30 UTC | 2h 15m |
| 2026-06-10 | USC31 | - | Jun 10, 07:25 UTC | Jun 10, 09:20 UTC | 1h 55m |
| 2026-06-09 | USC40 | - | Jun 9, 07:45 UTC | Jun 9, 09:20 UTC | 1h 35m |
| 2026-06-09 | USC40 | OKC → CHS | Jun 9, 04:40 UTC | Jun 9, 06:55 UTC | 2h 15m |
| 2026-06-09 | USC40 | BUR → OKC | Jun 9, 00:45 UTC | Jun 9, 03:05 UTC | 2h 20m |
| 2026-06-08 | USC240 | - | Jun 8, 02:30 UTC | Jun 8, 03:20 UTC | 50m |
| 2026-06-08 | USC240 | PDX → OAK | Jun 8, 00:40 UTC | Jun 8, 01:55 UTC | 1h 15m |
| 2026-06-07 | USC240 | - | Jun 7, 21:00 UTC | Jun 8, 00:00 UTC | 3h 0m |
| 2026-06-07 | USC240 | - | Jun 7, 18:10 UTC | Jun 7, 20:15 UTC | 2h 5m |
| 2026-06-02 | USC270 | - | Jun 2, 04:40 UTC | Jun 2, 06:25 UTC | 1h 45m |
| 2026-06-02 | USC270 | OAK → APA | Jun 2, 01:15 UTC | Jun 2, 03:15 UTC | 2h 0m |
| 2026-06-01 | USC102 | - | Jun 1, 01:25 UTC | Jun 1, 02:15 UTC | 50m |
| 2026-06-01 | USC102 | PHX → BUR | Jun 1, 00:05 UTC | Jun 1, 01:10 UTC | 1h 5m |
| 2026-05-31 | USC102 | BED → PHX | May 31, 15:35 UTC | May 31, 21:35 UTC | 6h 0m |
| 2026-05-31 | USC242 | - | May 31, 12:25 UTC | May 31, 13:55 UTC | 1h 30m |
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 N644CK page for operator, model, and routing details .