Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A81AA7

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N621HD · DASSAULT Falcon 2000 · operated by XLS AVIATION LLC

Hex
A81AA7
Octal
52015247
Decimal
11,016,871
Country
US
Tail
N621HD
Type
F2TH
No current signal · last broadcast 11d ago
Flights observed
93
Distinct callsigns
1
Country
US
Last broadcast
11d ago

Last known position

Most recent position reported by Mode-S A81AA7.

Country allocation

The ICAO 24-bit address A81AA7 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
N621HD - 93 2026-07-24

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-24 N621HD FCM → PIE Jul 24, 17:00 UTCJul 24, 19:35 UTC2h 35m
2026-07-23 N621HD ORL → FCM Jul 23, 20:55 UTCJul 23, 23:55 UTC3h 0m
2026-07-23 N621HD - Jul 23, 18:45 UTCJul 23, 20:10 UTC1h 25m
2026-07-23 N621HD - Jul 23, 16:35 UTCJul 23, 17:35 UTC1h 0m
2026-07-22 N621HD - Jul 22, 22:55 UTCJul 22, 23:45 UTC50m
2026-07-22 N621HD - Jul 22, 21:10 UTCJul 22, 22:30 UTC1h 20m
2026-07-22 N621HD - Jul 22, 14:20 UTCJul 22, 16:55 UTC2h 35m
2026-07-21 N621HD - Jul 21, 21:10 UTCJul 21, 22:05 UTC55m
2026-07-21 N621HD ORL → FCM Jul 21, 17:25 UTCJul 21, 20:55 UTC3h 30m
2026-07-21 N621HD FCM → ORL Jul 21, 13:20 UTCJul 21, 15:50 UTC2h 30m
2026-07-20 N621HD PHX → FCM Jul 20, 18:45 UTCJul 20, 21:20 UTC2h 35m
2026-07-19 N621HD - Jul 19, 22:40 UTCJul 20, 01:15 UTC2h 35m
2026-07-19 N621HD - Jul 19, 21:15 UTCJul 19, 22:15 UTC1h 0m
2026-07-19 N621HD - Jul 19, 20:00 UTCJul 19, 20:45 UTC45m
2026-07-17 N621HD - Jul 17, 23:55 UTCJul 18, 01:50 UTC1h 55m
2026-07-17 N621HD - Jul 17, 21:30 UTCJul 17, 23:20 UTC1h 50m
2026-07-17 N621HD - Jul 17, 19:20 UTCJul 17, 20:50 UTC1h 30m
2026-07-17 N621HD - Jul 17, 17:20 UTCJul 17, 18:50 UTC1h 30m
2026-07-15 N621HD FTY → APA Jul 15, 22:25 UTCJul 16, 00:50 UTC2h 25m
2026-07-15 N621HD PHL → FTY Jul 15, 13:25 UTCJul 15, 15:00 UTC1h 35m
2026-07-14 N621HD - Jul 14, 23:30 UTCJul 15, 02:45 UTC3h 15m
2026-07-14 N621HD FCM → APA Jul 14, 21:15 UTCJul 14, 22:55 UTC1h 39m
2026-07-14 N621HD - Jul 14, 19:40 UTCJul 14, 20:40 UTC1h 0m
2026-07-14 N621HD - Jul 14, 16:45 UTCJul 14, 18:05 UTC1h 20m
2026-07-14 N621HD - Jul 14, 14:25 UTCJul 14, 16:05 UTC1h 40m
2026-07-12 N621HD - Jul 12, 16:40 UTCJul 12, 17:40 UTC1h 0m
2026-07-12 N621HD - Jul 12, 15:01 UTCJul 12, 16:10 UTC1h 10m
2026-07-10 N621HD - Jul 10, 20:45 UTCJul 10, 21:40 UTC55m
2026-07-10 N621HD - Jul 10, 18:15 UTCJul 10, 19:25 UTC1h 10m
2026-07-08 N621HD - Jul 8, 02:40 UTCJul 8, 03:35 UTC55m
2026-07-08 N621HD - Jul 8, 00:10 UTCJul 8, 02:25 UTC2h 15m
2026-07-07 N621HD - Jul 7, 14:05 UTCJul 7, 16:10 UTC2h 5m
2026-07-07 N621HD - Jul 7, 12:25 UTCJul 7, 13:30 UTC1h 5m
2026-07-07 N621HD - Jul 7, 01:55 UTCJul 7, 03:30 UTC1h 35m
2026-07-06 N621HD - Jul 6, 19:15 UTCJul 6, 21:00 UTC1h 45m
2026-07-02 N621HD - Jul 2, 21:00 UTCJul 2, 22:05 UTC1h 5m
2026-07-02 N621HD - Jul 2, 18:20 UTCJul 2, 20:25 UTC2h 5m
2026-07-02 N621HD FCM → USA Jul 2, 15:35 UTCJul 2, 17:45 UTC2h 10m
2026-07-02 N621HD - Jul 2, 13:40 UTCJul 2, 14:55 UTC1h 15m
2026-06-25 N621HD - Jun 25, 21:05 UTCJun 25, 21:59 UTC55m
2026-06-25 N621HD - Jun 25, 18:19 UTCJun 25, 20:34 UTC2h 15m
2026-06-25 N621HD - Jun 25, 16:05 UTCJun 25, 17:44 UTC1h 40m
2026-06-25 N621HD PIE → ORL Jun 25, 15:10 UTCJun 25, 15:40 UTC30m
2026-06-23 N621HD - Jun 23, 21:29 UTCJun 23, 21:54 UTC25m
2026-06-23 N621HD - Jun 23, 19:34 UTCJun 23, 20:59 UTC1h 25m
2026-06-23 N621HD - Jun 23, 18:14 UTCJun 23, 18:55 UTC40m
2026-06-22 N621HD - Jun 22, 18:04 UTCJun 22, 19:54 UTC1h 50m
2026-06-22 N621HD PIE → ORL Jun 22, 17:10 UTCJun 22, 17:40 UTC30m
2026-06-20 N621HD MCO → PIE Jun 20, 23:25 UTCJun 20, 23:50 UTC25m
2026-06-20 N621HD - Jun 20, 20:25 UTCJun 20, 22:05 UTC1h 40m

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 N621HD page for operator, model, and routing details .

Mode-S A81AA7 frequently asked

What is Mode-S code A81AA7?
A81AA7 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N621HD.
Where is Mode-S A81AA7 registered?
Mode-S code A81AA7 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 A81AA7 broadcasting right now?
No active broadcast right now. Last signal was 11d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A81AA7, octal 52015247, decimal 11,016,871.
What flights does A81AA7 operate?
Mode-S A81AA7 has broadcast 1 distinct callsign, including N621HD.