sensors Mode-S transponder

AD81A1

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N97DK · BOMBARDIER BD-100 Challenger 300 · operated by JOURNEY & HOME INC

Hex
AD81A1
Octal
53300641
Decimal
11,370,913
Country
US
Tail
N97DK
Type
CL30
No current signal · last broadcast 11h ago
Flights observed
28
Distinct callsigns
2
Country
US
Last broadcast
11h ago

Last known position

Most recent position reported by Mode-S AD81A1.

Country allocation

The ICAO 24-bit address AD81A1 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 2 distinct

Callsign Airline Flights Last seen
EJM200 - 25 2026-05-29
TEST - 3 2026-04-13

Recent flights last 28

DateFlightRouteTakeoffLandingDuration
2026-05-29 EJM200 - May 29, 17:25 UTCMay 29, 19:10 UTC1h 45m
2026-05-28 EJM200 - May 28, 14:50 UTCMay 28, 18:05 UTC3h 15m
2026-05-27 EJM200 PSQ → SRQ May 27, 23:00 UTCMay 28, 02:20 UTC3h 20m
2026-05-21 EJM200 - May 21, 03:10 UTCMay 21, 04:35 UTC1h 25m
2026-05-20 EJM200 - May 20, 11:55 UTCMay 20, 13:35 UTC1h 40m
2026-05-15 EJM200 - May 15, 16:15 UTCMay 15, 16:45 UTC30m
2026-05-15 EJM200 - May 15, 12:50 UTCMay 15, 15:25 UTC2h 34m
2026-05-14 EJM200 - May 14, 19:25 UTCMay 14, 21:45 UTC2h 20m
2026-05-14 EJM200 - May 14, 12:05 UTCMay 14, 12:50 UTC45m
2026-05-14 EJM200 - May 14, 10:40 UTCMay 14, 11:05 UTC25m
2026-05-06 EJM200 - May 6, 15:20 UTCMay 6, 16:00 UTC40m
2026-05-03 EJM200 - May 3, 19:05 UTCMay 3, 22:05 UTC3h 0m
2026-05-03 EJM200 - May 3, 15:00 UTCMay 3, 17:24 UTC2h 25m
2026-05-01 EJM200 - May 1, 01:35 UTCMay 1, 02:30 UTC55m
2026-04-30 EJM200 - Apr 30, 21:30 UTCMay 1, 01:15 UTC3h 45m
2026-04-29 EJM200 - Apr 29, 20:40 UTCApr 29, 22:20 UTC1h 40m
2026-04-29 EJM200 - Apr 29, 14:10 UTCApr 29, 20:00 UTC5h 50m
2026-04-29 EJM200 - Apr 29, 11:35 UTCApr 29, 12:50 UTC1h 15m
2026-04-17 EJM200 - Apr 17, 23:25 UTCApr 17, 23:45 UTC20m
2026-04-17 EJM200 - Apr 17, 22:15 UTCApr 17, 23:20 UTC1h 5m
2026-04-17 EJM200 - Apr 17, 13:20 UTCApr 17, 14:00 UTC40m
2026-04-17 EJM200 - Apr 17, 12:20 UTCApr 17, 13:15 UTC55m
2026-04-13 EJM200 - Apr 13, 19:50 UTCApr 13, 23:35 UTC3h 45m
2026-04-13 EJM200 - Apr 13, 19:40 UTCApr 13, 19:45 UTC5m
2026-04-13 EJM200 SJC → LAS Apr 13, 04:30 UTCApr 13, 05:35 UTC1h 5m
2026-04-13 TEST DEN → SJC Apr 13, 01:20 UTCApr 13, 03:45 UTC2h 25m
2026-04-12 TEST - Apr 12, 23:55 UTCApr 13, 00:05 UTC10m
2026-04-12 TEST - Apr 12, 19:45 UTCApr 12, 20:15 UTC30m

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 N97DK page for operator, model, and routing details .

Mode-S AD81A1 frequently asked

What is Mode-S code AD81A1?
AD81A1 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N97DK.
Where is Mode-S AD81A1 registered?
Mode-S code AD81A1 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 AD81A1 broadcasting right now?
No active broadcast right now. Last signal was 11h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AD81A1, octal 53300641, decimal 11,370,913.
What flights does AD81A1 operate?
Mode-S AD81A1 has broadcast 2 distinct callsigns, including EJM200, TEST.