sensors Mode-S transponder

A1021A

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N164S · PILATUS PC-12 · operated by LIFE FLIGHT NETWORK LLC

Hex
A1021A
Octal
50201032
Decimal
10,551,834
Country
US
Tail
N164S
Type
PC12
No current signal · last broadcast 3d ago
Flights observed
39
Distinct callsigns
1
Country
US
Last broadcast
3d ago

Last known position

Most recent position reported by Mode-S A1021A.

Country allocation

The ICAO 24-bit address A1021A 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
N164S - 39 2026-05-29

Recent flights last 39

DateFlightRouteTakeoffLandingDuration
2026-05-29 N164S - May 29, 22:50 UTCMay 29, 23:45 UTC55m
2026-05-29 N164S - May 29, 20:15 UTCMay 29, 20:45 UTC30m
2026-05-29 N164S - May 29, 19:30 UTCMay 29, 19:40 UTC10m
2026-05-29 N164S - May 29, 17:25 UTCMay 29, 18:45 UTC1h 20m
2026-05-26 N164S - May 26, 22:50 UTCMay 26, 23:45 UTC55m
2026-05-19 N164S - May 19, 19:25 UTCMay 19, 19:55 UTC30m
2026-05-19 N164S - May 19, 15:05 UTCMay 19, 15:35 UTC30m
2026-05-15 N164S - May 15, 22:05 UTCMay 15, 22:40 UTC35m
2026-05-15 N164S - May 15, 20:40 UTCMay 15, 21:15 UTC35m
2026-05-15 N164S - May 15, 18:50 UTCMay 15, 19:55 UTC1h 5m
2026-05-15 N164S - May 15, 05:20 UTCMay 15, 07:50 UTC2h 30m
2026-05-15 N164S - May 15, 03:20 UTCMay 15, 03:50 UTC30m
2026-05-14 N164S - May 14, 23:20 UTCMay 15, 00:20 UTC1h 0m
2026-05-13 N164S - May 13, 20:05 UTCMay 13, 21:00 UTC55m
2026-05-13 N164S - May 13, 18:15 UTCMay 13, 19:05 UTC50m
2026-05-13 N164S - May 13, 03:10 UTCMay 13, 04:20 UTC1h 10m
2026-05-11 N164S HIO → BFI May 11, 21:10 UTCMay 11, 21:50 UTC40m
2026-05-11 N164S - May 11, 18:50 UTCMay 11, 19:20 UTC30m
2026-05-11 N164S - May 11, 16:55 UTCMay 11, 17:30 UTC36m
2026-05-11 N164S - May 11, 13:25 UTCMay 11, 13:30 UTC5m
2026-05-08 N164S - May 8, 21:05 UTCMay 8, 22:20 UTC1h 15m
2026-05-08 N164S - May 8, 19:25 UTCMay 8, 20:30 UTC1h 5m
2026-05-04 N164S - May 4, 22:20 UTCMay 4, 22:30 UTC10m
2026-05-01 N164S - May 1, 01:10 UTCMay 1, 01:40 UTC30m
2026-04-29 N164S - Apr 29, 20:35 UTCApr 29, 22:10 UTC1h 35m
2026-04-29 N164S - Apr 29, 14:30 UTCApr 29, 15:00 UTC30m
2026-04-28 N164S - Apr 28, 19:35 UTCApr 28, 20:05 UTC30m
2026-04-28 N164S - Apr 28, 15:55 UTCApr 28, 16:20 UTC25m
2026-04-27 N164S - Apr 27, 18:55 UTCApr 27, 20:05 UTC1h 10m
2026-04-17 N164S - Apr 17, 20:40 UTCApr 17, 21:10 UTC30m
2026-04-17 N164S - Apr 17, 15:45 UTCApr 17, 16:15 UTC30m
2026-04-17 N164S - Apr 17, 00:15 UTCApr 17, 01:15 UTC1h 0m
2026-04-16 N164S - Apr 16, 23:20 UTCApr 16, 23:45 UTC25m
2026-04-16 N164S - Apr 16, 22:45 UTCApr 16, 23:05 UTC20m
2026-04-16 N164S - Apr 16, 17:54 UTCApr 16, 18:55 UTC1h 0m
2026-04-16 N164S - Apr 16, 16:05 UTCApr 16, 17:10 UTC1h 5m
2026-04-13 N164S - Apr 13, 20:10 UTCApr 13, 21:05 UTC55m
2026-04-13 N164S - Apr 13, 16:15 UTCApr 13, 16:45 UTC30m
2026-04-13 N164S - Apr 13, 16:00 UTCApr 13, 16:15 UTC15m

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 N164S page for operator, model, and routing details .

Mode-S A1021A frequently asked

What is Mode-S code A1021A?
A1021A is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N164S.
Where is Mode-S A1021A registered?
Mode-S code A1021A 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 A1021A broadcasting right now?
No active broadcast right now. Last signal was 3d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1021A, octal 50201032, decimal 10,551,834.
What flights does A1021A operate?
Mode-S A1021A has broadcast 1 distinct callsign, including N164S.