Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A81A73

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N621FB · AEROSPATIALE AS-350 Ecureuil · operated by CITY OF PHOENIX, POLICE AIR SUPPORT UNIT

Hex
A81A73
Octal
52015163
Decimal
11,016,819
Country
US
Tail
N621FB
Type
AS50
No current signal · last broadcast 1h ago
Flights observed
191
Distinct callsigns
1
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A81A73.

Country allocation

The ICAO 24-bit address A81A73 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
N621FB - 191 2026-07-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 N621FB DVT → DVT Jul 14, 08:00 UTCJul 14, 09:30 UTC1h 30m
2026-07-14 N621FB - Jul 14, 06:05 UTCJul 14, 06:40 UTC35m
2026-07-14 N621FB - Jul 14, 05:00 UTCJul 14, 06:00 UTC1h 0m
2026-07-13 N621FB - Jul 13, 23:05 UTCJul 14, 00:30 UTC1h 25m
2026-07-13 N621FB - Jul 13, 02:05 UTCJul 13, 02:45 UTC40m
2026-07-12 N621FB - Jul 12, 23:05 UTCJul 13, 00:35 UTC1h 30m
2026-07-12 N621FB - Jul 12, 02:05 UTCJul 12, 03:35 UTC1h 30m
2026-07-11 N621FB - Jul 11, 23:05 UTCJul 12, 00:50 UTC1h 45m
2026-07-11 N621FB - Jul 11, 06:35 UTCJul 11, 08:10 UTC1h 35m
2026-07-11 N621FB - Jul 11, 03:35 UTCJul 11, 05:20 UTC1h 45m
2026-07-10 N621FB - Jul 10, 07:25 UTCJul 10, 08:05 UTC40m
2026-07-10 N621FB - Jul 10, 06:35 UTCJul 10, 07:20 UTC45m
2026-07-10 N621FB DVT → DVT Jul 10, 03:35 UTCJul 10, 05:15 UTC1h 40m
2026-07-08 N621FB - Jul 8, 16:05 UTCJul 8, 16:50 UTC45m
2026-07-08 N621FB - Jul 8, 08:00 UTCJul 8, 09:30 UTC1h 30m
2026-07-08 N621FB - Jul 8, 05:05 UTCJul 8, 06:40 UTC1h 35m
2026-07-07 N621FB DVT → DVT Jul 7, 06:30 UTCJul 7, 08:05 UTC1h 35m
2026-07-07 N621FB - Jul 7, 03:35 UTCJul 7, 05:05 UTC1h 30m
2026-07-06 N621FB - Jul 6, 08:05 UTCJul 6, 09:35 UTC1h 30m
2026-07-06 N621FB - Jul 6, 05:05 UTCJul 6, 06:40 UTC1h 35m
2026-07-05 N621FB - Jul 5, 08:05 UTCJul 5, 10:10 UTC2h 5m
2026-07-05 N621FB DVT → DVT Jul 5, 05:00 UTCJul 5, 06:35 UTC1h 35m
2026-07-04 N621FB - Jul 4, 08:00 UTCJul 4, 09:55 UTC1h 55m
2026-07-04 N621FB - Jul 4, 05:05 UTCJul 4, 06:40 UTC1h 35m
2026-07-03 N621FB - Jul 3, 08:05 UTCJul 3, 09:30 UTC1h 25m
2026-07-03 N621FB - Jul 3, 05:05 UTCJul 3, 06:35 UTC1h 30m
2026-07-01 N621FB - Jul 1, 18:35 UTCJul 1, 20:50 UTC2h 15m
2026-07-01 N621FB DVT → DVT Jul 1, 15:15 UTCJul 1, 16:20 UTC1h 5m
2026-06-29 N621FB - Jun 29, 06:34 UTCJun 29, 08:14 UTC1h 40m
2026-06-29 N621FB - Jun 29, 03:54 UTCJun 29, 05:09 UTC1h 15m
2026-06-28 N621FB DVT → DVT Jun 28, 06:30 UTCJun 28, 08:05 UTC1h 35m
2026-06-28 N621FB - Jun 28, 03:40 UTCJun 28, 05:09 UTC1h 30m
2026-06-27 N621FB DVT → DVT Jun 27, 06:30 UTCJun 27, 08:29 UTC2h 0m
2026-06-27 N621FB DVT → DVT Jun 27, 03:34 UTCJun 27, 05:04 UTC1h 30m
2026-06-26 N621FB - Jun 26, 16:20 UTCJun 26, 16:30 UTC10m
2026-06-26 N621FB - Jun 26, 15:25 UTCJun 26, 15:34 UTC10m
2026-06-26 N621FB DVT → DVT Jun 26, 06:29 UTCJun 26, 08:10 UTC1h 40m
2026-06-26 N621FB - Jun 26, 03:29 UTCJun 26, 05:10 UTC1h 40m
2026-06-22 N621FB DVT → DVT Jun 22, 06:35 UTCJun 22, 08:10 UTC1h 35m
2026-06-22 N621FB - Jun 22, 03:40 UTCJun 22, 05:20 UTC1h 40m
2026-06-22 N621FB - Jun 22, 01:00 UTCJun 22, 02:25 UTC1h 25m
2026-06-21 N621FB - Jun 21, 21:14 UTCJun 21, 22:00 UTC45m
2026-06-19 N621FB - Jun 19, 18:34 UTCJun 19, 20:29 UTC1h 55m
2026-06-19 N621FB - Jun 19, 15:34 UTCJun 19, 16:29 UTC55m
2026-06-18 N621FB - Jun 18, 18:50 UTCJun 18, 19:55 UTC1h 5m
2026-06-18 N621FB - Jun 18, 15:30 UTCJun 18, 17:00 UTC1h 30m
2026-06-18 N621FB DVT → DVT Jun 18, 06:35 UTCJun 18, 08:10 UTC1h 35m
2026-06-18 N621FB DVT → DVT Jun 18, 03:30 UTCJun 18, 05:25 UTC1h 55m
2026-06-17 N621FB DVT → DVT Jun 17, 15:40 UTCJun 17, 17:20 UTC1h 40m
2026-06-17 N621FB - Jun 17, 08:00 UTCJun 17, 09:40 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 N621FB page for operator, model, and routing details .

Mode-S A81A73 frequently asked

What is Mode-S code A81A73?
A81A73 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N621FB.
Where is Mode-S A81A73 registered?
Mode-S code A81A73 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 A81A73 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A81A73, octal 52015163, decimal 11,016,819.
What flights does A81A73 operate?
Mode-S A81A73 has broadcast 1 distinct callsign, including N621FB.