sensors Mode-S transponder
AB729E
ICAO 24-bit transponder address · allocated to United States
Currently assigned to N837CS · AIRBUS HELICOPTERS EC-135/635 · operated by REACH AIR MEDICAL SERVICES LLC
- Hex
- AB729E
- Octal
- 52671236
- Decimal
- 11,235,998
- Country
- US
- Tail
- N837CS
- Type
- EC35
- Flights observed
- 44
- Distinct callsigns
- 3
- Country
- US
- Last broadcast
- 12h ago
Last known position
Country allocation
The ICAO 24-bit address AB729E 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 3 distinct
Recent flights last 44
| Date | Flight | Route | Takeoff | Landing | Duration |
|---|---|---|---|---|---|
| 2026-06-30 | REH86 | - | Jun 30, 17:40 UTC | Jun 30, 17:55 UTC | 15m |
| 2026-06-25 | REH86 | - | Jun 25, 18:59 UTC | Jun 25, 19:15 UTC | 15m |
| 2026-06-25 | REH86 | - | Jun 25, 17:49 UTC | Jun 25, 18:00 UTC | 10m |
| 2026-06-24 | REH86 | - | Jun 24, 16:50 UTC | Jun 24, 17:20 UTC | 30m |
| 2026-06-23 | REH86 | - | Jun 23, 21:29 UTC | Jun 23, 21:39 UTC | 10m |
| 2026-06-17 | REH86 | - | Jun 17, 22:00 UTC | Jun 17, 22:25 UTC | 25m |
| 2026-06-17 | REH86 | - | Jun 17, 17:20 UTC | Jun 17, 17:35 UTC | 15m |
| 2026-06-17 | REH86 | - | Jun 17, 16:30 UTC | Jun 17, 16:40 UTC | 10m |
| 2026-06-12 | REH86 | - | Jun 12, 21:20 UTC | Jun 12, 21:45 UTC | 25m |
| 2026-06-11 | REH86 | - | Jun 11, 03:20 UTC | Jun 11, 03:40 UTC | 20m |
| 2026-06-10 | REH86 | - | Jun 10, 16:10 UTC | Jun 10, 16:25 UTC | 15m |
| 2026-06-06 | REH86 | - | Jun 6, 17:15 UTC | Jun 6, 17:49 UTC | 35m |
| 2026-06-05 | REH86 | - | Jun 5, 20:40 UTC | Jun 5, 21:15 UTC | 35m |
| 2026-06-01 | REH99 | - | Jun 1, 14:50 UTC | Jun 1, 15:55 UTC | 1h 5m |
| 2026-05-29 | REH99 | - | May 29, 20:35 UTC | May 29, 21:10 UTC | 35m |
| 2026-05-29 | REH99 | - | May 29, 16:20 UTC | May 29, 16:30 UTC | 10m |
| 2026-05-28 | REH99 | - | May 28, 20:20 UTC | May 28, 21:10 UTC | 50m |
| 2026-05-28 | CMD13 | - | May 28, 02:15 UTC | May 28, 04:45 UTC | 2h 30m |
| 2026-05-27 | CMD13 | - | May 27, 07:35 UTC | May 27, 07:45 UTC | 10m |
| 2026-05-27 | CMD13 | - | May 27, 06:09 UTC | May 27, 07:00 UTC | 51m |
| 2026-05-26 | CMD13 | - | May 26, 10:20 UTC | May 26, 10:54 UTC | 35m |
| 2026-05-26 | CMD13 | - | May 26, 08:45 UTC | May 26, 09:25 UTC | 40m |
| 2026-05-26 | CMD13 | - | May 26, 01:05 UTC | May 26, 01:40 UTC | 35m |
| 2026-05-25 | CMD13 | - | May 25, 22:25 UTC | May 25, 22:49 UTC | 25m |
| 2026-05-25 | CMD13 | - | May 25, 05:35 UTC | May 25, 05:50 UTC | 15m |
| 2026-05-25 | CMD13 | - | May 25, 04:35 UTC | May 25, 04:45 UTC | 10m |
| 2026-05-24 | CMD13 | - | May 24, 14:10 UTC | May 24, 14:25 UTC | 15m |
| 2026-05-24 | CMD13 | - | May 24, 13:15 UTC | May 24, 13:35 UTC | 20m |
| 2026-05-23 | CMD13 | - | May 23, 15:00 UTC | May 23, 15:15 UTC | 15m |
| 2026-05-23 | CMD13 | - | May 23, 08:05 UTC | May 23, 08:20 UTC | 15m |
| 2026-05-22 | CMD13 | - | May 22, 23:00 UTC | May 22, 23:15 UTC | 15m |
| 2026-05-22 | CMD13 | - | May 22, 22:10 UTC | May 22, 22:20 UTC | 10m |
| 2026-05-13 | REH86 | - | May 13, 20:30 UTC | May 13, 20:40 UTC | 10m |
| 2026-05-12 | REH86 | - | May 12, 20:35 UTC | May 12, 21:20 UTC | 45m |
| 2026-05-09 | REH86 | - | May 9, 18:30 UTC | May 9, 19:05 UTC | 35m |
| 2026-05-03 | REH86 | - | May 3, 00:45 UTC | May 3, 01:15 UTC | 30m |
| 2026-05-02 | REH86 | - | May 2, 19:45 UTC | May 2, 20:25 UTC | 40m |
| 2026-05-01 | REH86 | - | May 1, 18:35 UTC | May 1, 19:10 UTC | 35m |
| 2026-04-30 | REH86 | - | Apr 30, 17:25 UTC | Apr 30, 17:40 UTC | 15m |
| 2026-04-29 | REH86 | - | Apr 29, 17:40 UTC | Apr 29, 18:00 UTC | 20m |
| 2026-04-20 | REH86 | - | Apr 20, 22:35 UTC | Apr 20, 23:15 UTC | 40m |
| 2026-04-16 | REH86 | - | Apr 16, 18:05 UTC | Apr 16, 18:25 UTC | 20m |
| 2026-04-13 | REH86 | - | Apr 13, 18:40 UTC | Apr 13, 18:50 UTC | 10m |
| 2026-04-12 | REH86 | - | Apr 12, 18:10 UTC | Apr 12, 18:25 UTC | 15m |
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 N837CS page for operator, model, and routing details .