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sensors Mode-S transponder

ACD251

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N925SD · operated by SHIPMAN HOLDINGS I LLC

Hex
ACD251
Octal
53151121
Decimal
11,326,033
Country
US
Tail
N925SD
Type
PC12
No current signal · last broadcast 5d ago
Flights observed
86
Distinct callsigns
1
Country
US
Last broadcast
5d ago

Last known position

Most recent position reported by Mode-S ACD251.

Country allocation

The ICAO 24-bit address ACD251 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
N925SD - 86 2026-07-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-21 N925SD - Jul 21, 20:05 UTCJul 21, 22:45 UTC2h 40m
2026-07-19 N925SD - Jul 19, 18:10 UTCJul 19, 19:00 UTC50m
2026-07-18 N925SD - Jul 18, 12:50 UTCJul 18, 13:30 UTC40m
2026-07-18 N925SD - Jul 18, 10:50 UTCJul 18, 11:55 UTC1h 5m
2026-07-16 N925SD - Jul 16, 22:00 UTCJul 17, 00:04 UTC2h 5m
2026-07-16 N925SD - Jul 16, 14:15 UTCJul 16, 19:20 UTC5h 5m
2026-07-15 N925SD RBD → CLD Jul 15, 22:55 UTCJul 16, 03:20 UTC4h 25m
2026-07-14 N925SD - Jul 14, 19:50 UTCJul 14, 21:15 UTC1h 25m
2026-07-14 N925SD - Jul 14, 13:25 UTCJul 14, 15:00 UTC1h 35m
2026-07-09 N925SD - Jul 9, 22:30 UTCJul 9, 23:10 UTC40m
2026-07-09 N925SD - Jul 9, 16:00 UTCJul 9, 16:35 UTC35m
2026-07-08 N925SD - Jul 8, 16:45 UTCJul 8, 16:55 UTC10m
2026-07-08 N925SD - Jul 8, 14:40 UTCJul 8, 15:45 UTC1h 5m
2026-07-08 N925SD - Jul 8, 11:45 UTCJul 8, 12:45 UTC1h 0m
2026-07-04 N925SD - Jul 4, 20:55 UTCJul 4, 22:05 UTC1h 10m
2026-07-04 N925SD - Jul 4, 12:25 UTCJul 4, 13:25 UTC1h 0m
2026-07-03 N925SD - Jul 3, 22:30 UTCJul 3, 23:40 UTC1h 10m
2026-07-03 N925SD - Jul 3, 20:10 UTCJul 3, 21:15 UTC1h 5m
2026-07-03 N925SD - Jul 3, 18:25 UTCJul 3, 18:35 UTC10m
2026-06-30 N925SD CLD → DAL Jun 30, 19:00 UTCJun 30, 23:25 UTC4h 25m
2026-06-28 N925SD VGT → CLD Jun 28, 19:20 UTCJun 28, 20:39 UTC1h 20m
2026-06-25 N925SD - Jun 25, 21:29 UTCJun 25, 22:45 UTC1h 15m
2026-06-24 N925SD - Jun 24, 21:14 UTCJun 25, 02:05 UTC4h 50m
2026-06-21 N925SD - Jun 21, 14:59 UTCJun 21, 16:04 UTC1h 5m
2026-06-21 N925SD - Jun 21, 13:34 UTCJun 21, 14:24 UTC50m
2026-06-20 N925SD - Jun 20, 17:29 UTCJun 20, 19:44 UTC2h 15m
2026-06-16 N925SD - Jun 16, 18:15 UTCJun 16, 22:40 UTC4h 26m
2026-06-15 N925SD - Jun 15, 15:59 UTCJun 15, 20:54 UTC4h 55m
2026-06-15 N925SD - Jun 15, 13:05 UTCJun 15, 14:00 UTC55m
2026-06-15 N925SD - Jun 15, 02:04 UTCJun 15, 03:35 UTC1h 30m
2026-06-14 N925SD - Jun 14, 21:05 UTCJun 15, 01:04 UTC3h 59m
2026-06-12 N925SD - Jun 12, 15:55 UTCJun 12, 19:30 UTC3h 35m
2026-06-12 N925SD - Jun 12, 14:15 UTCJun 12, 15:15 UTC1h 0m
2026-06-12 N925SD - Jun 12, 11:45 UTCJun 12, 12:35 UTC50m
2026-06-11 N925SD - Jun 11, 15:05 UTCJun 11, 16:05 UTC1h 0m
2026-06-11 N925SD - Jun 11, 13:00 UTCJun 11, 13:55 UTC55m
2026-06-07 N925SD - Jun 7, 20:20 UTCJun 7, 21:20 UTC1h 0m
2026-06-06 N925SD - Jun 6, 12:35 UTCJun 6, 13:44 UTC1h 10m
2026-06-05 N925SD - Jun 5, 00:35 UTCJun 5, 01:30 UTC55m
2026-06-04 N925SD - Jun 4, 23:50 UTCJun 5, 00:10 UTC20m
2026-06-04 N925SD - Jun 4, 22:25 UTCJun 4, 23:05 UTC40m
2026-06-04 N925SD - Jun 4, 20:05 UTCJun 4, 21:10 UTC1h 5m
2026-06-04 N925SD - Jun 4, 00:45 UTCJun 4, 02:20 UTC1h 35m
2026-06-03 N925SD - Jun 3, 22:40 UTCJun 3, 23:45 UTC1h 5m
2026-06-03 N925SD - Jun 3, 19:55 UTCJun 3, 20:20 UTC25m
2026-06-03 N925SD - Jun 3, 17:50 UTCJun 3, 18:45 UTC55m
2026-06-03 N925SD - Jun 3, 14:55 UTCJun 3, 16:00 UTC1h 5m
2026-06-03 N925SD - Jun 3, 01:05 UTCJun 3, 01:45 UTC40m
2026-06-02 N925SD - Jun 2, 22:10 UTCJun 2, 22:55 UTC45m
2026-06-01 N925SD - Jun 1, 20:55 UTCJun 1, 21:45 UTC50m

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 N925SD page for operator, model, and routing details .

Mode-S ACD251 frequently asked

What is Mode-S code ACD251?
ACD251 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N925SD.
Where is Mode-S ACD251 registered?
Mode-S code ACD251 is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is ACD251 broadcasting right now?
No active broadcast right now. Last signal was 5d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ACD251, octal 53151121, decimal 11,326,033.
What flights does ACD251 operate?
Mode-S ACD251 has broadcast 1 distinct callsign, including N925SD.