sensors Mode-S transponder
1540A1
ICAO 24-bit transponder address · allocated to Russia
Currently assigned to RA-82081 · ANTONOV An-124 Ruslan
- Hex
- 1540A1
- Octal
- 05240241
- Decimal
- 1,392,801
- Country
- RU
- Tail
- RA-82081
- Type
- A124
- Flights observed
- 6
- Distinct callsigns
- 4
- Country
- RU
- Last broadcast
- 21h ago
Last known position
Country allocation
The ICAO 24-bit address 1540A1 falls within the block assigned to Russia (RU) by ICAO Annex 10, Volume III. Every aircraft registered in Russia 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 4 distinct
Recent flights last 6
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-05-19 | VDA716 | - | May 19, 22:45 UTC | May 19, 23:20 UTC | 35m |
| 2026-05-19 | VDA716 | - | May 19, 14:10 UTC | May 19, 14:40 UTC | 30m |
| 2026-05-17 | VDA715 | - | May 17, 16:30 UTC | May 18, 08:50 UTC | 16h 20m |
| 2026-05-16 | VDA516 | - | May 16, 19:20 UTC | May 16, 19:55 UTC | 35m |
| 2026-05-15 | VDA5159 | - | May 15, 20:30 UTC | May 16, 19:55 UTC | 23h 26m |
| 2026-05-15 | VDA5159 | - | May 15, 18:10 UTC | May 15, 21:15 UTC | 3h 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 RA-82081 page for operator, model, and routing details .