sensors Mode-S transponder
773645
ICAO 24-bit transponder address · allocated to Sri Lanka
Currently assigned to 4R-MRE · AIRBUS A-320
- Hex
- 773645
- Octal
- 35633105
- Decimal
- 7,812,677
- Country
- LK
- Tail
- 4R-MRE
- Type
- A320
- Flights observed
- 294
- Distinct callsigns
- 20
- Country
- LK
- Last broadcast
- Jul 24, 23:40 UTC
Last known position
Country allocation
The ICAO 24-bit address 773645 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 |
|---|---|---|---|
| ALK141 | SriLankan Airlines | 50 | 2026-07-24 |
| ALK142 | SriLankan Airlines | 46 | 2026-07-24 |
| ALK191 | SriLankan Airlines | 12 | 2026-07-22 |
| ALK144 | - | 11 | 2026-07-23 |
| ALK195 | - | 10 | 2026-07-21 |
| ALK167 | - | 10 | 2026-06-29 |
| ALK161 | - | 10 | 2026-06-29 |
| ALK168 | - | 9 | 2026-06-29 |
| ALK162 | - | 9 | 2026-06-29 |
| ALK192 | SriLankan Airlines | 8 | 2026-07-20 |
| ALK174 | - | 8 | 2026-07-21 |
| ALK143 | SriLankan Airlines | 8 | 2026-07-23 |
| ALK196 | - | 7 | 2026-07-21 |
| ALK166 | - | 7 | 2026-07-05 |
| ALK173 | SriLankan Airlines | 6 | 2026-07-07 |
| ALK124 | SriLankan Airlines | 6 | 2026-05-21 |
| ALK364 | - | 5 | 2026-06-20 |
| ALK165 | SriLankan Airlines | 5 | 2026-06-09 |
| ALK123 | SriLankan Airlines | 5 | 2026-05-07 |
| ALK306 | - | 4 | 2026-07-03 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-24 | ALK142 | BOM → CMB | Jul 24, 22:00 UTC | Jul 24, 23:40 UTC | 1h 40m |
| 2026-07-24 | ALK141 | CMB → BOM | Jul 24, 04:55 UTC | Jul 24, 20:30 UTC | 15h 35m |
| 2026-07-24 | ALK1173 | CMB → BLR | Jul 24, 03:00 UTC | Jul 24, 03:20 UTC | 20m |
| 2026-07-23 | ALK144 | - | Jul 23, 16:10 UTC | Jul 23, 17:55 UTC | 1h 45m |
| 2026-07-23 | ALK143 | CMB → BOM | Jul 23, 00:15 UTC | Jul 23, 14:30 UTC | 14h 15m |
| 2026-07-22 | ALK191 | CMB → DEL | Jul 22, 04:00 UTC | Jul 22, 22:45 UTC | 18h 45m |
| 2026-07-21 | ALK174 | - | Jul 21, 22:15 UTC | Jul 22, 20:25 UTC | 22h 10m |
| 2026-07-21 | ALK196 | - | Jul 21, 13:40 UTC | Jul 21, 20:50 UTC | 7h 10m |
| 2026-07-21 | ALK195 | - | Jul 21, 09:35 UTC | Jul 21, 12:05 UTC | 2h 30m |
| 2026-07-20 | ALK142 | BOM → CMB | Jul 20, 21:55 UTC | Jul 20, 23:35 UTC | 1h 40m |
| 2026-07-20 | ALK141 | CMB → BOM | Jul 20, 13:45 UTC | Jul 20, 20:35 UTC | 6h 50m |
| 2026-07-20 | ALK195 | - | Jul 20, 11:35 UTC | Jul 20, 12:10 UTC | 35m |
| 2026-07-20 | ALK192 | DEL → CMB | Jul 20, 00:10 UTC | Jul 20, 10:00 UTC | 9h 50m |
| 2026-07-19 | ALK196 | - | Jul 19, 13:35 UTC | Jul 19, 22:45 UTC | 9h 10m |
| 2026-07-19 | ALK195 | - | Jul 19, 09:40 UTC | Jul 19, 12:05 UTC | 2h 25m |
| 2026-07-18 | ALK195 | - | Jul 18, 16:50 UTC | Jul 19, 12:05 UTC | 19h 15m |
| 2026-07-18 | ALK103 | - | Jul 18, 14:00 UTC | Jul 19, 09:50 UTC | 19h 50m |
| 2026-07-17 | ALK104 | - | Jul 17, 17:20 UTC | Jul 18, 17:00 UTC | 23h 41m |
| 2026-07-17 | ALK104 | - | Jul 17, 17:05 UTC | Jul 18, 14:10 UTC | 21h 6m |
| 2026-07-17 | ALK103 | - | Jul 17, 10:55 UTC | Jul 17, 17:20 UTC | 6h 25m |
| 2026-07-17 | ALK1174 | - | Jul 17, 05:10 UTC | Jul 17, 08:54 UTC | 3h 45m |
| 2026-07-17 | ALK1173 | - | Jul 17, 02:50 UTC | Jul 17, 03:30 UTC | 40m |
| 2026-07-16 | ALK184 | KHI → CMB | Jul 16, 13:49 UTC | Jul 16, 16:30 UTC | 2h 40m |
| 2026-07-16 | ALK183 | - | Jul 16, 09:25 UTC | Jul 16, 11:40 UTC | 2h 15m |
| 2026-07-15 | ALK142 | - | Jul 15, 22:00 UTC | Jul 15, 23:45 UTC | 1h 45m |
| 2026-07-15 | ALK141 | - | Jul 15, 18:50 UTC | Jul 15, 20:35 UTC | 1h 45m |
| 2026-07-14 | ALK142 | - | Jul 14, 21:55 UTC | Jul 15, 06:10 UTC | 8h 14m |
| 2026-07-14 | ALK141 | - | Jul 14, 19:00 UTC | Jul 14, 20:35 UTC | 1h 35m |
| 2026-07-13 | ALK142 | - | Jul 13, 22:50 UTC | Jul 14, 00:35 UTC | 1h 45m |
| 2026-07-13 | ALK141 | - | Jul 13, 13:40 UTC | Jul 13, 20:40 UTC | 7h 0m |
| 2026-07-13 | ALK195 | - | Jul 13, 09:50 UTC | Jul 13, 12:05 UTC | 2h 15m |
| 2026-07-11 | ALK144 | - | Jul 11, 16:35 UTC | Jul 11, 17:35 UTC | 1h 0m |
| 2026-07-11 | ALK144 | - | Jul 11, 15:50 UTC | Jul 11, 16:00 UTC | 10m |
| 2026-07-11 | ALK143 | CMB → BOM | Jul 11, 13:55 UTC | Jul 11, 14:15 UTC | 20m |
| 2026-07-11 | ALK143 | CMB → BOM | Jul 11, 07:35 UTC | Jul 11, 13:15 UTC | 5h 40m |
| 2026-07-11 | ALK404 | - | Jul 11, 05:15 UTC | Jul 11, 05:35 UTC | 20m |
| 2026-07-10 | ALK142 | - | Jul 10, 22:45 UTC | Jul 10, 23:45 UTC | 1h 0m |
| 2026-07-10 | ALK142 | - | Jul 10, 22:00 UTC | Jul 10, 22:10 UTC | 10m |
| 2026-07-10 | ALK141 | - | Jul 10, 20:20 UTC | Jul 10, 20:30 UTC | 10m |
| 2026-07-10 | ALK141 | - | Jul 10, 19:00 UTC | Jul 10, 19:45 UTC | 45m |
| 2026-07-07 | ALK174 | - | Jul 7, 22:00 UTC | Jul 8, 11:25 UTC | 13h 25m |
| 2026-07-07 | ALK173 | CMB → BLR | Jul 7, 19:55 UTC | Jul 7, 20:30 UTC | 35m |
| 2026-07-06 | ALK142 | - | Jul 6, 22:45 UTC | Jul 7, 09:20 UTC | 10h 35m |
| 2026-07-06 | ALK142 | - | Jul 6, 22:00 UTC | Jul 6, 22:10 UTC | 10m |
| 2026-07-06 | ALK141 | - | Jul 6, 20:20 UTC | Jul 6, 20:45 UTC | 25m |
| 2026-07-06 | ALK141 | - | Jul 6, 14:05 UTC | Jul 6, 19:45 UTC | 5h 40m |
| 2026-07-06 | ALK195 | - | Jul 6, 00:00 UTC | Jul 6, 12:00 UTC | 12h 0m |
| 2026-07-05 | ALK191 | - | Jul 5, 20:10 UTC | Jul 5, 22:30 UTC | 2h 20m |
| 2026-07-05 | ALK166 | - | Jul 5, 06:30 UTC | Jul 5, 07:00 UTC | 30m |
| 2026-07-05 | ALK192 | DEL → COK | Jul 5, 00:05 UTC | Jul 5, 05:10 UTC | 5h 5m |
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-MRE page for operator, model, and routing details .