sensors Mode-S transponder
4CAF00
ICAO 24-bit transponder address · allocated to Ireland
Currently assigned to EI-HRF · BOEING 737-800
- Hex
- 4CAF00
- Octal
- 23127400
- Decimal
- 5,025,536
- Country
- IE
- Tail
- EI-HRF
- Type
- B738
- Flights observed
- 31
- Distinct callsigns
- 7
- Country
- IE
- Last broadcast
- 1d ago
Last known position
Country allocation
The ICAO 24-bit address 4CAF00 falls within the block assigned to Ireland (IE) by ICAO Annex 10, Volume III. Every aircraft registered in Ireland 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 7 distinct
Recent flights last 31
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-06-01 | CGS4418 | - | Jun 1, 20:20 UTC | Jun 1, 20:50 UTC | 30m |
| 2026-05-31 | CGS4421 | - | May 31, 23:20 UTC | May 31, 23:50 UTC | 30m |
| 2026-05-29 | CGS4418 | - | May 29, 00:15 UTC | May 29, 00:40 UTC | 25m |
| 2026-05-28 | CGS4421 | - | May 28, 21:45 UTC | May 28, 22:15 UTC | 30m |
| 2026-05-28 | CGS4420 | DWC → NBO | May 28, 16:35 UTC | May 28, 16:50 UTC | 15m |
| 2026-05-27 | CGS4418 | - | May 27, 02:24 UTC | May 27, 02:54 UTC | 30m |
| 2026-05-26 | CGS4421 | - | May 26, 21:40 UTC | May 26, 22:05 UTC | 25m |
| 2026-05-23 | CGS706 | - | May 23, 18:30 UTC | May 23, 19:20 UTC | 50m |
| 2026-05-22 | CGS708 | - | May 22, 17:15 UTC | May 22, 18:55 UTC | 1h 40m |
| 2026-05-22 | CGS707 | - | May 22, 13:25 UTC | May 22, 14:30 UTC | 1h 5m |
| 2026-05-21 | CGS707 | - | May 21, 17:35 UTC | May 22, 14:30 UTC | 20h 55m |
| 2026-05-21 | CGS705 | - | May 21, 13:55 UTC | May 21, 15:20 UTC | 1h 25m |
| 2026-05-14 | CGS4418 | - | May 14, 23:40 UTC | May 15, 00:10 UTC | 30m |
| 2026-05-14 | CGS4421 | - | May 14, 21:30 UTC | May 14, 22:05 UTC | 35m |
| 2026-05-12 | CGS4418 | - | May 12, 23:35 UTC | May 13, 00:05 UTC | 30m |
| 2026-05-12 | CGS4421 | - | May 12, 21:35 UTC | May 12, 22:05 UTC | 30m |
| 2026-05-07 | CGS4418 | - | May 7, 23:45 UTC | May 8, 00:14 UTC | 30m |
| 2026-05-07 | CGS4421 | - | May 7, 22:00 UTC | May 7, 22:30 UTC | 30m |
| 2026-05-04 | CGS4418 | - | May 4, 21:00 UTC | May 4, 21:30 UTC | 30m |
| 2026-05-04 | CGS4421 | - | May 4, 00:10 UTC | May 4, 00:40 UTC | 30m |
| 2026-04-27 | CGS4418 | - | Apr 27, 20:05 UTC | Apr 27, 20:35 UTC | 30m |
| 2026-04-27 | CGS4421 | - | Apr 27, 02:20 UTC | Apr 27, 02:50 UTC | 30m |
| 2026-04-22 | CGS4418 | - | Apr 22, 00:35 UTC | Apr 22, 01:05 UTC | 30m |
| 2026-04-21 | CGS4421 | - | Apr 21, 22:05 UTC | Apr 21, 22:30 UTC | 25m |
| 2026-04-20 | CGS4418 | - | Apr 20, 21:30 UTC | Apr 20, 21:55 UTC | 25m |
| 2026-04-19 | CGS4421 | - | Apr 19, 23:45 UTC | Apr 20, 00:15 UTC | 30m |
| 2026-04-17 | CGS4418 | - | Apr 17, 00:10 UTC | Apr 17, 00:35 UTC | 25m |
| 2026-04-16 | CGS4421 | - | Apr 16, 22:00 UTC | Apr 16, 22:30 UTC | 30m |
| 2026-04-14 | CGS4418 | - | Apr 14, 22:10 UTC | Apr 14, 22:35 UTC | 25m |
| 2026-04-14 | CGS4421 | - | Apr 14, 19:50 UTC | Apr 14, 20:20 UTC | 30m |
| 2026-04-13 | CGS4418 | - | Apr 13, 21:00 UTC | Apr 13, 21:30 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.
Prefer a tail-number view? See the EI-HRF page for operator, model, and routing details .