sensors Mode-S transponder
7705C3
ICAO 24-bit transponder address · allocated to Sri Lanka
Currently assigned to 4R-ANC · AIRBUS A-321neo
- Hex
- 7705C3
- Octal
- 35602703
- Decimal
- 7,800,259
- Country
- LK
- Tail
- 4R-ANC
- Type
- A21N
- Flights observed
- 268
- Distinct callsigns
- 20
- Country
- LK
- Last broadcast
- 2h ago
Current position
Country allocation
The ICAO 24-bit address 7705C3 falls within the block assigned to Sri Lanka (LK) by ICAO Annex 10, Volume III. Every aircraft registered in Sri Lanka 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 20 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| ALK254 | - | 25 | 2026-07-12 |
| ALK253 | - | 25 | 2026-07-14 |
| ALK364 | - | 24 | 2026-07-13 |
| ALK404 | - | 18 | 2026-07-12 |
| ALK217 | SriLankan Airlines | 18 | 2026-07-07 |
| ALK218 | - | 15 | 2026-07-07 |
| ALK365 | - | 12 | 2026-07-11 |
| ALK141 | - | 12 | 2026-07-05 |
| ALK142 | - | 11 | 2026-07-05 |
| ALK405 | - | 10 | 2026-07-09 |
| ALK314 | - | 8 | 2026-06-23 |
| ALK318 | SriLankan Airlines | 7 | 2026-05-19 |
| ALK315 | - | 7 | 2026-06-23 |
| ALK166 | - | 7 | 2026-06-30 |
| ALK89L | - | 5 | 2026-06-29 |
| ALK90L | - | 4 | 2026-06-29 |
| ALK319 | SriLankan Airlines | 4 | 2026-05-20 |
| ALK168 | - | 4 | 2026-07-08 |
| ALK161 | SriLankan Airlines | 4 | 2026-06-02 |
| ALK885 | SriLankan Airlines | 3 | 2026-04-30 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-14 | ALK253 | - | Jul 14, 13:20 UTC | Jul 14, 17:45 UTC | 4h 25m |
| 2026-07-13 | ALK26L | - | Jul 13, 19:35 UTC | Jul 13, 23:25 UTC | 3h 50m |
| 2026-07-13 | ALK25L | - | Jul 13, 08:05 UTC | Jul 13, 17:25 UTC | 9h 20m |
| 2026-07-13 | ALK364 | - | Jul 13, 06:20 UTC | Jul 13, 06:35 UTC | 15m |
| 2026-07-13 | ALK364 | - | Jul 13, 05:10 UTC | Jul 13, 05:31 UTC | 20m |
| 2026-07-12 | ALK254 | - | Jul 12, 19:40 UTC | Jul 13, 00:05 UTC | 4h 25m |
| 2026-07-12 | ALK253 | - | Jul 12, 07:31 UTC | Jul 12, 17:35 UTC | 10h 5m |
| 2026-07-12 | ALK404 | - | Jul 12, 05:05 UTC | Jul 12, 05:30 UTC | 25m |
| 2026-07-11 | ALK254 | - | Jul 11, 19:40 UTC | Jul 11, 23:55 UTC | 4h 15m |
| 2026-07-11 | ALK253 | - | Jul 11, 14:00 UTC | Jul 11, 18:05 UTC | 4h 5m |
| 2026-07-11 | ALK365 | - | Jul 11, 08:25 UTC | Jul 11, 08:40 UTC | 15m |
| 2026-07-11 | ALK364 | - | Jul 11, 06:25 UTC | Jul 11, 06:45 UTC | 20m |
| 2026-07-10 | ALK26L | - | Jul 10, 19:25 UTC | Jul 11, 05:50 UTC | 10h 25m |
| 2026-07-10 | ALK25L | - | Jul 10, 17:25 UTC | Jul 10, 17:45 UTC | 20m |
| 2026-07-10 | ALK25L | - | Jul 10, 14:10 UTC | Jul 10, 14:35 UTC | 25m |
| 2026-07-10 | ALK365 | - | Jul 10, 08:40 UTC | Jul 10, 09:05 UTC | 25m |
| 2026-07-10 | ALK364 | - | Jul 10, 06:45 UTC | Jul 10, 07:05 UTC | 20m |
| 2026-07-09 | ALK230 | - | Jul 9, 19:05 UTC | Jul 10, 06:05 UTC | 11h 0m |
| 2026-07-09 | ALK229 | - | Jul 9, 12:20 UTC | Jul 9, 16:35 UTC | 4h 15m |
| 2026-07-09 | ALK405 | - | Jul 9, 07:35 UTC | Jul 9, 08:55 UTC | 1h 20m |
| 2026-07-09 | ALK404 | - | Jul 9, 05:25 UTC | Jul 9, 05:55 UTC | 30m |
| 2026-07-08 | ALK254 | - | Jul 8, 20:10 UTC | Jul 9, 00:45 UTC | 4h 35m |
| 2026-07-08 | ALK253 | - | Jul 8, 13:20 UTC | Jul 8, 17:40 UTC | 4h 20m |
| 2026-07-08 | ALK168 | - | Jul 8, 11:00 UTC | Jul 8, 11:30 UTC | 30m |
| 2026-07-08 | ALK167 | - | Jul 8, 09:10 UTC | Jul 8, 09:35 UTC | 25m |
| 2026-07-07 | ALK218 | - | Jul 7, 19:55 UTC | Jul 8, 00:10 UTC | 4h 15m |
| 2026-07-07 | ALK217 | CMB → DOH | Jul 7, 07:05 UTC | Jul 7, 17:50 UTC | 10h 45m |
| 2026-07-07 | ALK404 | - | Jul 7, 04:50 UTC | Jul 7, 05:25 UTC | 35m |
| 2026-07-06 | ALK254 | - | Jul 6, 20:10 UTC | Jul 7, 00:20 UTC | 4h 10m |
| 2026-07-06 | ALK253 | - | Jul 6, 14:05 UTC | Jul 6, 18:25 UTC | 4h 20m |
| 2026-07-06 | ALK365 | - | Jul 6, 08:30 UTC | Jul 6, 08:40 UTC | 10m |
| 2026-07-06 | ALK364 | - | Jul 6, 06:35 UTC | Jul 6, 06:55 UTC | 20m |
| 2026-07-06 | ALK364 | - | Jul 6, 05:20 UTC | Jul 6, 05:40 UTC | 20m |
| 2026-07-05 | ALK142 | - | Jul 5, 22:35 UTC | Jul 5, 23:30 UTC | 55m |
| 2026-07-05 | ALK142 | - | Jul 5, 21:50 UTC | Jul 5, 22:00 UTC | 10m |
| 2026-07-05 | ALK141 | - | Jul 5, 20:10 UTC | Jul 5, 20:35 UTC | 25m |
| 2026-07-05 | ALK309 | SIN → CMB | Jul 5, 12:45 UTC | Jul 5, 19:40 UTC | 6h 55m |
| 2026-07-05 | ALK308 | - | Jul 5, 09:50 UTC | Jul 5, 10:55 UTC | 1h 5m |
| 2026-07-04 | ALK254 | - | Jul 4, 20:30 UTC | Jul 5, 00:45 UTC | 4h 15m |
| 2026-07-04 | ALK253 | - | Jul 4, 14:30 UTC | Jul 4, 18:45 UTC | 4h 15m |
| 2026-07-04 | ALK365 | - | Jul 4, 09:00 UTC | Jul 4, 09:20 UTC | 20m |
| 2026-07-04 | ALK364 | - | Jul 4, 06:00 UTC | Jul 4, 07:15 UTC | 1h 15m |
| 2026-07-03 | ALK218 | - | Jul 3, 20:00 UTC | Jul 4, 00:00 UTC | 4h 0m |
| 2026-07-03 | ALK217 | CMB → DOH | Jul 3, 14:25 UTC | Jul 3, 18:35 UTC | 4h 10m |
| 2026-07-03 | ALK365 | - | Jul 3, 09:05 UTC | Jul 3, 09:25 UTC | 20m |
| 2026-07-03 | ALK364 | - | Jul 3, 06:35 UTC | Jul 3, 06:50 UTC | 15m |
| 2026-07-03 | ALK364 | - | Jul 3, 05:35 UTC | Jul 3, 06:00 UTC | 25m |
| 2026-07-02 | ALK230 | - | Jul 2, 19:25 UTC | Jul 3, 00:00 UTC | 4h 35m |
| 2026-07-02 | ALK229 | - | Jul 2, 12:15 UTC | Jul 2, 16:40 UTC | 4h 25m |
| 2026-07-02 | ALK192 | - | Jul 2, 00:05 UTC | Jul 2, 02:15 UTC | 2h 10m |
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 4R-ANC page for operator, model, and routing details .