sensors Mode-S transponder
A73D39
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N566AE · operated by US NAVAL TEST PILOT SCHOOL
- Hex
- A73D39
- Octal
- 51636471
- Decimal
- 10,960,185
- Country
- US
- Tail
- N566AE
- Type
- EC45
- Flights observed
- 44
- Distinct callsigns
- 4
- Country
- US
- Last broadcast
- 57m ago
Last known position
Country allocation
The ICAO 24-bit address A73D39 falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States 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 44
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-14 | TSTR70 | - | Jul 14, 14:05 UTC | Jul 14, 15:50 UTC | 1h 45m |
| 2026-07-13 | TSTR70 | - | Jul 13, 20:00 UTC | Jul 13, 20:10 UTC | 10m |
| 2026-07-13 | TSTR70 | - | Jul 13, 18:45 UTC | Jul 13, 19:10 UTC | 25m |
| 2026-07-13 | TSTR70 | - | Jul 13, 13:15 UTC | Jul 13, 14:45 UTC | 1h 30m |
| 2026-07-10 | TSTR70 | - | Jul 10, 13:55 UTC | Jul 10, 15:25 UTC | 1h 30m |
| 2026-07-08 | TSTR70 | - | Jul 8, 18:35 UTC | Jul 8, 20:20 UTC | 1h 45m |
| 2026-07-07 | TSTR70 | - | Jul 7, 14:50 UTC | Jul 7, 15:40 UTC | 50m |
| 2026-07-01 | VVHX70 | - | Jul 1, 19:55 UTC | Jul 1, 20:05 UTC | 10m |
| 2026-07-01 | VVHX70 | - | Jul 1, 18:10 UTC | Jul 1, 18:25 UTC | 15m |
| 2026-06-30 | DBD70 | - | Jun 30, 15:35 UTC | Jun 30, 15:55 UTC | 20m |
| 2026-06-30 | DBD70 | - | Jun 30, 14:30 UTC | Jun 30, 15:00 UTC | 30m |
| 2026-06-24 | TSTR70 | - | Jun 24, 14:20 UTC | Jun 24, 15:35 UTC | 1h 15m |
| 2026-06-23 | VVHX070 | LTW → NHK | Jun 23, 15:40 UTC | Jun 23, 15:50 UTC | 10m |
| 2026-06-23 | VVHX070 | - | Jun 23, 13:59 UTC | Jun 23, 14:10 UTC | 10m |
| 2026-06-22 | TSTR70 | - | Jun 22, 20:04 UTC | Jun 22, 21:05 UTC | 1h 0m |
| 2026-06-11 | TSTR70 | NHK → NHK | Jun 11, 13:00 UTC | Jun 11, 14:10 UTC | 1h 10m |
| 2026-06-09 | TSTR70 | NHK → NHK | Jun 9, 20:50 UTC | Jun 9, 21:20 UTC | 30m |
| 2026-06-09 | TSTR70 | - | Jun 9, 13:05 UTC | Jun 9, 15:00 UTC | 1h 55m |
| 2026-06-05 | TSTR70 | - | Jun 5, 17:35 UTC | Jun 5, 19:35 UTC | 2h 0m |
| 2026-06-04 | TSTR70 | NHK → NHK | Jun 4, 18:15 UTC | Jun 4, 19:30 UTC | 1h 15m |
| 2026-06-04 | VVHX70 | - | Jun 4, 14:50 UTC | Jun 4, 15:20 UTC | 30m |
| 2026-06-04 | VVHX70 | - | Jun 4, 13:30 UTC | Jun 4, 13:45 UTC | 15m |
| 2026-06-02 | VVHX70 | NHK → NHK | Jun 2, 18:15 UTC | Jun 2, 19:40 UTC | 1h 25m |
| 2026-06-02 | VVHX70 | - | Jun 2, 14:05 UTC | Jun 2, 15:45 UTC | 1h 40m |
| 2026-06-01 | TSTR70 | NHK → NHK | Jun 1, 14:35 UTC | Jun 1, 15:10 UTC | 35m |
| 2026-06-01 | TSTR70 | - | Jun 1, 14:00 UTC | Jun 1, 14:25 UTC | 25m |
| 2026-05-22 | VVHX70 | NHK → NHK | May 22, 17:35 UTC | May 22, 18:45 UTC | 1h 10m |
| 2026-05-22 | VVHX70 | NHK → NHK | May 22, 14:25 UTC | May 22, 14:55 UTC | 30m |
| 2026-05-22 | VVHX70 | NHK → NHK | May 22, 13:40 UTC | May 22, 14:20 UTC | 40m |
| 2026-05-13 | VVHX70 | - | May 13, 19:25 UTC | May 13, 21:15 UTC | 1h 50m |
| 2026-05-13 | VVHX70 | - | May 13, 14:30 UTC | May 13, 15:00 UTC | 30m |
| 2026-05-13 | VVHX70 | - | May 13, 13:31 UTC | May 13, 13:45 UTC | 15m |
| 2026-05-08 | VVHX70 | - | May 8, 13:55 UTC | May 8, 14:45 UTC | 50m |
| 2026-05-06 | VVHX70 | - | May 6, 13:45 UTC | May 6, 15:30 UTC | 1h 45m |
| 2026-05-01 | VVHX70 | - | May 1, 18:10 UTC | May 1, 18:20 UTC | 10m |
| 2026-04-30 | TSTR70 | - | Apr 30, 13:40 UTC | Apr 30, 14:25 UTC | 45m |
| 2026-04-30 | TSTR70 | - | Apr 30, 12:45 UTC | Apr 30, 13:35 UTC | 50m |
| 2026-04-29 | TSTR70 | - | Apr 29, 19:30 UTC | Apr 29, 21:20 UTC | 1h 50m |
| 2026-04-29 | TSTR70 | - | Apr 29, 14:20 UTC | Apr 29, 15:15 UTC | 55m |
| 2026-04-29 | TSTR70 | - | Apr 29, 13:15 UTC | Apr 29, 14:15 UTC | 1h 0m |
| 2026-04-28 | TSTR70 | - | Apr 28, 18:50 UTC | Apr 28, 20:50 UTC | 2h 0m |
| 2026-04-28 | TSTR70 | NHK → NHK | Apr 28, 14:00 UTC | Apr 28, 14:30 UTC | 30m |
| 2026-04-27 | TSTR70 | - | Apr 27, 13:20 UTC | Apr 27, 13:50 UTC | 30m |
| 2026-04-23 | TSTR70 | - | Apr 23, 19:25 UTC | Apr 23, 20:30 UTC | 1h 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 N566AE page for operator, model, and routing details .