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sensors Mode-S transponder

A0FFF4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N16351 · PIPER PA-28-140/150/160/180 · operated by DEGRAAFF NORMAN L, DEGRAAFF TERESA M

Hex
A0FFF4
Octal
50177764
Decimal
10,551,284
Country
US
Tail
N16351
Type
P28A
No current signal · last broadcast Jul 22, 00:50 UTC
Flights observed
22
Distinct callsigns
1
Country
US
Last broadcast
Jul 22, 00:50 UTC

Last known position

Most recent position reported by Mode-S A0FFF4.

Country allocation

The ICAO 24-bit address A0FFF4 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
N16351 - 22 2026-07-22

Recent flights last 22

DateFlightRouteTakeoffLandingDuration
2026-07-22 N16351 - Jul 22, 00:35 UTCJul 22, 00:50 UTC15m
2026-07-21 N16351 FRD → BLI Jul 21, 16:30 UTCJul 21, 16:50 UTC20m
2026-07-20 N16351 - Jul 20, 01:40 UTCJul 20, 02:25 UTC45m
2026-07-19 N16351 - Jul 19, 21:15 UTCJul 19, 21:35 UTC20m
2026-07-18 N16351 FBS → BLI Jul 18, 20:40 UTCJul 18, 20:55 UTC15m
2026-07-12 N16351 - Jul 12, 23:50 UTCJul 13, 00:05 UTC15m
2026-07-12 N16351 - Jul 12, 15:55 UTCJul 12, 16:10 UTC15m
2026-07-10 N16351 - Jul 10, 03:00 UTCJul 10, 03:15 UTC15m
2026-07-09 N16351 - Jul 9, 01:35 UTCJul 9, 01:50 UTC15m
2026-07-05 N16351 - Jul 5, 22:05 UTCJul 5, 22:35 UTC30m
2026-07-05 N16351 - Jul 5, 20:20 UTCJul 5, 21:30 UTC1h 10m
2026-07-04 N16351 - Jul 4, 01:55 UTCJul 4, 03:00 UTC1h 5m
2026-07-04 N16351 - Jul 4, 01:00 UTCJul 4, 01:10 UTC10m
2026-07-01 N16351 - Jul 1, 01:45 UTCJul 1, 02:00 UTC15m
2026-06-30 N16351 FBS → BLI Jun 30, 15:05 UTCJun 30, 15:20 UTC15m
2026-06-28 N16351 - Jun 28, 20:50 UTCJun 28, 21:04 UTC15m
2026-06-27 N16351 - Jun 27, 16:59 UTCJun 27, 17:14 UTC15m
2026-06-25 N16351 - Jun 25, 18:15 UTCJun 25, 18:34 UTC20m
2026-06-08 N16351 FBS → BLI Jun 8, 18:05 UTCJun 8, 18:25 UTC20m
2026-05-29 N16351 - May 29, 18:45 UTCMay 29, 19:00 UTC15m
2026-05-23 N16351 BLI → FBS May 23, 01:30 UTCMay 23, 01:50 UTC20m
2026-05-21 N16351 BYW → BLI May 21, 23:10 UTCMay 21, 23:25 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 N16351 page for operator, model, and routing details .

Mode-S A0FFF4 frequently asked

What is Mode-S code A0FFF4?
A0FFF4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N16351.
Where is Mode-S A0FFF4 registered?
Mode-S code A0FFF4 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 A0FFF4 broadcasting right now?
No active broadcast right now. Last signal was Jul 22, 00:50 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A0FFF4, octal 50177764, decimal 10,551,284.
What flights does A0FFF4 operate?
Mode-S A0FFF4 has broadcast 1 distinct callsign, including N16351.