sensors Mode-S transponder
ADEF77
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N9973T · PIPER PA-38 Tomahawk · operated by MENNO DAVID L
- Hex
- ADEF77
- Octal
- 53367567
- Decimal
- 11,399,031
- Country
- US
- Tail
- N9973T
- Type
- PA38
- Flights observed
- 63
- Distinct callsigns
- 1
- Country
- US
- Last broadcast
- 7d ago
Last known position
Country allocation
The ICAO 24-bit address ADEF77 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 1 distinct
| Callsign | Airline | Flights | Last seen |
|---|---|---|---|
| N9973T | - | 63 | 2026-07-25 |
Recent flights last 50
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-07-25 | N9973T | - | Jul 25, 14:50 UTC | Jul 25, 16:45 UTC | 1h 55m |
| 2026-07-23 | N9973T | - | Jul 23, 19:15 UTC | Jul 23, 20:15 UTC | 1h 0m |
| 2026-07-23 | N9973T | - | Jul 23, 16:05 UTC | Jul 23, 16:35 UTC | 30m |
| 2026-07-20 | N9973T | - | Jul 20, 19:25 UTC | Jul 20, 20:15 UTC | 50m |
| 2026-07-20 | N9973T | - | Jul 20, 16:15 UTC | Jul 20, 17:05 UTC | 50m |
| 2026-07-13 | N9973T | - | Jul 13, 18:55 UTC | Jul 13, 19:50 UTC | 55m |
| 2026-07-13 | N9973T | - | Jul 13, 16:45 UTC | Jul 13, 17:55 UTC | 1h 10m |
| 2026-07-08 | N9973T | - | Jul 8, 19:40 UTC | Jul 8, 20:25 UTC | 45m |
| 2026-07-08 | N9973T | - | Jul 8, 17:15 UTC | Jul 8, 18:35 UTC | 1h 20m |
| 2026-07-08 | N9973T | - | Jul 8, 15:15 UTC | Jul 8, 15:40 UTC | 25m |
| 2026-07-07 | N9973T | - | Jul 7, 17:50 UTC | Jul 7, 18:15 UTC | 25m |
| 2026-07-07 | N9973T | - | Jul 7, 15:10 UTC | Jul 7, 15:35 UTC | 25m |
| 2026-06-29 | N9973T | - | Jun 29, 20:09 UTC | Jun 29, 21:14 UTC | 1h 5m |
| 2026-06-27 | N9973T | - | Jun 27, 17:39 UTC | Jun 27, 19:24 UTC | 1h 45m |
| 2026-06-24 | N9973T | - | Jun 24, 18:05 UTC | Jun 24, 18:55 UTC | 50m |
| 2026-06-24 | N9973T | - | Jun 24, 15:59 UTC | Jun 24, 16:50 UTC | 50m |
| 2026-06-24 | N9973T | - | Jun 24, 13:14 UTC | Jun 24, 13:44 UTC | 30m |
| 2026-06-21 | N9973T | - | Jun 21, 19:39 UTC | Jun 21, 20:29 UTC | 50m |
| 2026-06-21 | N9973T | - | Jun 21, 11:44 UTC | Jun 21, 12:14 UTC | 30m |
| 2026-06-17 | N9973T | - | Jun 17, 14:55 UTC | Jun 17, 16:30 UTC | 1h 35m |
| 2026-06-16 | N9973T | - | Jun 16, 16:20 UTC | Jun 16, 17:10 UTC | 50m |
| 2026-06-16 | N9973T | - | Jun 16, 14:45 UTC | Jun 16, 15:35 UTC | 50m |
| 2026-06-15 | N9973T | - | Jun 15, 16:55 UTC | Jun 15, 18:25 UTC | 1h 30m |
| 2026-06-09 | N9973T | - | Jun 9, 18:25 UTC | Jun 9, 19:00 UTC | 35m |
| 2026-06-09 | N9973T | - | Jun 9, 15:25 UTC | Jun 9, 15:50 UTC | 25m |
| 2026-06-07 | N9973T | - | Jun 7, 19:00 UTC | Jun 7, 19:50 UTC | 50m |
| 2026-06-07 | N9973T | - | Jun 7, 17:00 UTC | Jun 7, 17:55 UTC | 55m |
| 2026-06-05 | N9973T | - | Jun 5, 13:30 UTC | Jun 5, 14:35 UTC | 1h 5m |
| 2026-06-04 | N9973T | - | Jun 4, 17:00 UTC | Jun 4, 17:35 UTC | 35m |
| 2026-06-04 | N9973T | - | Jun 4, 16:05 UTC | Jun 4, 16:25 UTC | 20m |
| 2026-06-04 | N9973T | - | Jun 4, 13:35 UTC | Jun 4, 14:00 UTC | 25m |
| 2026-06-03 | N9973T | - | Jun 3, 13:20 UTC | Jun 3, 14:40 UTC | 1h 20m |
| 2026-06-02 | N9973T | - | Jun 2, 19:40 UTC | Jun 2, 20:30 UTC | 50m |
| 2026-06-01 | N9973T | - | Jun 1, 19:30 UTC | Jun 1, 20:20 UTC | 50m |
| 2026-06-01 | N9973T | - | Jun 1, 15:55 UTC | Jun 1, 16:40 UTC | 45m |
| 2026-05-30 | N9973T | - | May 30, 16:30 UTC | May 30, 16:45 UTC | 15m |
| 2026-05-28 | N9973T | - | May 28, 19:40 UTC | May 28, 20:20 UTC | 40m |
| 2026-05-27 | N9973T | - | May 27, 18:15 UTC | May 27, 18:35 UTC | 20m |
| 2026-05-26 | N9973T | - | May 26, 17:15 UTC | May 26, 18:05 UTC | 50m |
| 2026-05-26 | N9973T | - | May 26, 14:14 UTC | May 26, 15:14 UTC | 1h 0m |
| 2026-05-24 | N9973T | - | May 24, 19:25 UTC | May 24, 20:35 UTC | 1h 10m |
| 2026-05-20 | N9973T | - | May 20, 17:15 UTC | May 20, 18:00 UTC | 45m |
| 2026-05-19 | N9973T | - | May 19, 23:30 UTC | May 19, 23:55 UTC | 25m |
| 2026-05-18 | N9973T | - | May 18, 23:45 UTC | May 19, 00:25 UTC | 40m |
| 2026-05-18 | N9973T | - | May 18, 13:50 UTC | May 18, 14:25 UTC | 35m |
| 2026-05-17 | N9973T | - | May 17, 22:50 UTC | May 17, 23:55 UTC | 1h 5m |
| 2026-05-12 | N9973T | - | May 12, 15:10 UTC | May 12, 18:30 UTC | 3h 20m |
| 2026-05-11 | N9973T | - | May 11, 17:35 UTC | May 11, 19:00 UTC | 1h 25m |
| 2026-05-10 | N9973T | - | May 10, 15:19 UTC | May 10, 16:20 UTC | 1h 0m |
| 2026-05-10 | N9973T | - | May 10, 13:44 UTC | May 10, 14:45 UTC | 1h 0m |
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 N9973T page for operator, model, and routing details .