sensors Mode-S transponder
A4FA43
ICAO 24-bit transponder address · allocated to United States
- Hex
- A4FA43
- Octal
- 51175103
- Decimal
- 10,811,971
- Country
- US
- Flights observed
- 43
- Distinct callsigns
- 1
- Country
- US
- Last broadcast
- Jul 24, 20:35 UTC
Last known position
Country allocation
The ICAO 24-bit address A4FA43 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 |
|---|---|---|---|
| N42LC | - | 43 | 2026-07-24 |
Recent flights last 43
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-24 | N42LC | FRG → WWD | Jul 24, 19:45 UTC | Jul 24, 20:35 UTC | 50m |
| 2026-07-24 | N42LC | - | Jul 24, 15:15 UTC | Jul 24, 16:15 UTC | 1h 0m |
| 2026-07-19 | N42LC | - | Jul 19, 22:55 UTC | Jul 20, 00:50 UTC | 1h 55m |
| 2026-07-19 | N42LC | - | Jul 19, 20:45 UTC | Jul 19, 22:20 UTC | 1h 35m |
| 2026-07-16 | N42LC | - | Jul 16, 15:25 UTC | Jul 16, 16:25 UTC | 1h 0m |
| 2026-07-16 | N42LC | - | Jul 16, 13:54 UTC | Jul 16, 14:40 UTC | 45m |
| 2026-07-16 | N42LC | BLM → BED | Jul 16, 12:00 UTC | Jul 16, 13:20 UTC | 1h 20m |
| 2026-07-15 | N42LC | - | Jul 15, 21:30 UTC | Jul 15, 22:05 UTC | 35m |
| 2026-07-10 | N42LC | - | Jul 10, 12:20 UTC | Jul 10, 12:55 UTC | 35m |
| 2026-07-09 | N42LC | - | Jul 9, 16:15 UTC | Jul 9, 16:45 UTC | 30m |
| 2026-07-09 | N42LC | - | Jul 9, 12:35 UTC | Jul 9, 13:05 UTC | 30m |
| 2026-07-08 | N42LC | - | Jul 8, 17:20 UTC | Jul 8, 18:40 UTC | 1h 20m |
| 2026-07-07 | N42LC | - | Jul 7, 15:15 UTC | Jul 7, 16:55 UTC | 1h 40m |
| 2026-07-05 | N42LC | - | Jul 5, 14:05 UTC | Jul 5, 15:35 UTC | 1h 30m |
| 2026-07-02 | N42LC | - | Jul 2, 23:00 UTC | Jul 3, 00:35 UTC | 1h 35m |
| 2026-07-01 | N42LC | - | Jul 1, 18:30 UTC | Jul 1, 19:05 UTC | 35m |
| 2026-06-21 | N42LC | - | Jun 21, 22:15 UTC | Jun 21, 23:05 UTC | 50m |
| 2026-06-21 | N42LC | - | Jun 21, 20:05 UTC | Jun 21, 20:59 UTC | 55m |
| 2026-06-16 | N42LC | - | Jun 16, 12:50 UTC | Jun 16, 13:19 UTC | 30m |
| 2026-06-15 | N42LC | - | Jun 15, 11:10 UTC | Jun 15, 11:30 UTC | 20m |
| 2026-06-13 | N42LC | - | Jun 13, 13:20 UTC | Jun 13, 15:05 UTC | 1h 45m |
| 2026-06-08 | N42LC | - | Jun 8, 14:50 UTC | Jun 8, 15:25 UTC | 35m |
| 2026-06-08 | N42LC | - | Jun 8, 14:05 UTC | Jun 8, 14:20 UTC | 15m |
| 2026-05-31 | N42LC | - | May 31, 16:05 UTC | May 31, 17:05 UTC | 1h 0m |
| 2026-05-26 | N42LC | - | May 26, 15:35 UTC | May 26, 16:15 UTC | 40m |
| 2026-05-21 | N42LC | - | May 21, 20:55 UTC | May 21, 21:35 UTC | 40m |
| 2026-05-20 | N42LC | - | May 20, 19:10 UTC | May 20, 19:45 UTC | 35m |
| 2026-05-19 | N42LC | - | May 19, 20:35 UTC | May 19, 21:30 UTC | 55m |
| 2026-05-19 | N42LC | - | May 19, 19:15 UTC | May 19, 20:05 UTC | 50m |
| 2026-05-19 | N42LC | - | May 19, 15:10 UTC | May 19, 16:30 UTC | 1h 20m |
| 2026-05-17 | N42LC | - | May 17, 23:05 UTC | May 17, 23:45 UTC | 40m |
| 2026-05-08 | N42LC | - | May 8, 15:50 UTC | May 8, 16:25 UTC | 35m |
| 2026-05-08 | N42LC | - | May 8, 11:44 UTC | May 8, 12:30 UTC | 45m |
| 2026-05-06 | N42LC | - | May 6, 22:20 UTC | May 6, 23:15 UTC | 55m |
| 2026-05-04 | N42LC | - | May 4, 13:30 UTC | May 4, 16:20 UTC | 2h 50m |
| 2026-04-27 | N42LC | - | Apr 27, 21:00 UTC | Apr 27, 21:40 UTC | 40m |
| 2026-04-27 | N42LC | - | Apr 27, 19:25 UTC | Apr 27, 20:25 UTC | 1h 0m |
| 2026-04-27 | N42LC | - | Apr 27, 14:05 UTC | Apr 27, 15:35 UTC | 1h 30m |
| 2026-04-23 | N42LC | - | Apr 23, 17:40 UTC | Apr 23, 18:55 UTC | 1h 15m |
| 2026-04-23 | N42LC | - | Apr 23, 15:35 UTC | Apr 23, 16:45 UTC | 1h 10m |
| 2026-04-21 | N42LC | - | Apr 21, 15:35 UTC | Apr 21, 16:10 UTC | 35m |
| 2026-04-14 | N42LC | - | Apr 14, 16:50 UTC | Apr 14, 17:05 UTC | 15m |
| 2026-04-14 | N42LC | - | Apr 14, 15:10 UTC | Apr 14, 15:40 UTC | 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.