sensors Mode-S transponder
511199
ICAO 24-bit transponder address · allocated to Estonia
- Hex
- 511199
- Octal
- 24210631
- Decimal
- 5,312,921
- Country
- EE
- Flights observed
- 29
- Distinct callsigns
- 1
- Country
- EE
- Last broadcast
- 18d ago
Last known position
Country allocation
The ICAO 24-bit address 511199 falls within the block assigned to Estonia (EE) by ICAO Annex 10, Volume III. Every aircraft registered in Estonia 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 |
|---|---|---|---|
| ESEPH | - | 29 | 2026-07-01 |
Recent flights last 29
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-01 | ESEPH | - | Jul 1, 18:00 UTC | Jul 1, 18:35 UTC | 35m |
| 2026-06-28 | ESEPH | - | Jun 28, 15:20 UTC | Jun 28, 17:34 UTC | 2h 15m |
| 2026-06-26 | ESEPH | - | Jun 26, 05:30 UTC | Jun 26, 08:10 UTC | 2h 40m |
| 2026-06-25 | ESEPH | - | Jun 25, 08:24 UTC | Jun 25, 08:55 UTC | 30m |
| 2026-06-23 | ESEPH | - | Jun 23, 14:15 UTC | Jun 23, 15:04 UTC | 50m |
| 2026-06-23 | ESEPH | - | Jun 23, 05:04 UTC | Jun 23, 06:09 UTC | 1h 5m |
| 2026-06-22 | ESEPH | - | Jun 22, 13:05 UTC | Jun 22, 13:19 UTC | 15m |
| 2026-06-22 | ESEPH | - | Jun 22, 11:35 UTC | Jun 22, 12:15 UTC | 40m |
| 2026-06-14 | ESEPH | - | Jun 14, 13:45 UTC | Jun 14, 16:55 UTC | 3h 10m |
| 2026-06-14 | ESEPH | - | Jun 14, 09:25 UTC | Jun 14, 12:25 UTC | 3h 0m |
| 2026-06-11 | ESEPH | - | Jun 11, 11:10 UTC | Jun 11, 11:40 UTC | 30m |
| 2026-06-11 | ESEPH | - | Jun 11, 07:10 UTC | Jun 11, 09:40 UTC | 2h 30m |
| 2026-06-10 | ESEPH | - | Jun 10, 10:10 UTC | Jun 10, 13:50 UTC | 3h 40m |
| 2026-06-03 | ESEPH | - | Jun 3, 16:00 UTC | Jun 3, 16:20 UTC | 20m |
| 2026-06-03 | ESEPH | - | Jun 3, 14:50 UTC | Jun 3, 15:15 UTC | 25m |
| 2026-06-02 | ESEPH | - | Jun 2, 14:00 UTC | Jun 2, 14:40 UTC | 40m |
| 2026-05-29 | ESEPH | - | May 29, 17:00 UTC | May 29, 18:00 UTC | 1h 0m |
| 2026-05-29 | ESEPH | - | May 29, 16:05 UTC | May 29, 16:20 UTC | 15m |
| 2026-05-23 | ESEPH | - | May 23, 15:10 UTC | May 23, 15:50 UTC | 40m |
| 2026-05-22 | ESEPH | - | May 22, 16:10 UTC | May 22, 16:40 UTC | 30m |
| 2026-05-17 | ESEPH | - | May 17, 15:35 UTC | May 17, 16:35 UTC | 1h 0m |
| 2026-05-17 | ESEPH | - | May 17, 13:01 UTC | May 17, 14:30 UTC | 1h 30m |
| 2026-05-14 | ESEPH | - | May 14, 10:45 UTC | May 14, 13:55 UTC | 3h 10m |
| 2026-05-14 | ESEPH | - | May 14, 07:55 UTC | May 14, 08:25 UTC | 30m |
| 2026-05-02 | ESEPH | - | May 2, 13:10 UTC | May 2, 13:50 UTC | 40m |
| 2026-04-30 | ESEPH | - | Apr 30, 06:00 UTC | Apr 30, 06:30 UTC | 30m |
| 2026-04-19 | ESEPH | - | Apr 19, 14:20 UTC | Apr 19, 15:00 UTC | 40m |
| 2026-04-17 | ESEPH | - | Apr 17, 07:45 UTC | Apr 17, 07:55 UTC | 10m |
| 2026-04-17 | ESEPH | - | Apr 17, 06:25 UTC | Apr 17, 06:45 UTC | 20m |
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.