sensors Mode-S transponder

A71AB4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N557PC · PILATUS PC-12 · operated by TVPX AIRCRAFT SOLUTIONS INC TRUSTEE

Hex
A71AB4
Octal
51615264
Decimal
10,951,348
Country
US
Tail
N557PC
Type
PC12
No current signal · last broadcast 6d ago
Flights observed
227
Distinct callsigns
1
Country
US
Last broadcast
6d ago

Last known position

Most recent position reported by Mode-S A71AB4.

Country allocation

The ICAO 24-bit address A71AB4 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
N557PC - 227 2026-07-12

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-12 N557PC - Jul 12, 01:30 UTCJul 12, 02:05 UTC35m
2026-07-12 N557PC - Jul 12, 00:20 UTCJul 12, 00:35 UTC15m
2026-07-11 N557PC - Jul 11, 22:50 UTCJul 11, 23:40 UTC50m
2026-07-10 N557PC - Jul 10, 13:10 UTCJul 10, 13:35 UTC25m
2026-07-10 N557PC - Jul 10, 11:40 UTCJul 10, 11:55 UTC15m
2026-07-09 N557PC - Jul 9, 06:10 UTCJul 9, 06:30 UTC20m
2026-07-09 N557PC - Jul 9, 03:20 UTCJul 9, 03:30 UTC10m
2026-07-08 N557PC - Jul 8, 06:45 UTCJul 8, 07:05 UTC20m
2026-07-08 N557PC - Jul 8, 04:30 UTCJul 8, 04:55 UTC25m
2026-07-06 N557PC - Jul 6, 06:00 UTCJul 6, 06:20 UTC20m
2026-07-06 N557PC - Jul 6, 04:00 UTCJul 6, 04:20 UTC20m
2026-07-06 N557PC - Jul 6, 01:05 UTCJul 6, 02:00 UTC55m
2026-07-05 N557PC - Jul 5, 20:25 UTCJul 5, 21:25 UTC1h 0m
2026-07-05 N557PC - Jul 5, 11:40 UTCJul 5, 12:00 UTC20m
2026-07-05 N557PC - Jul 5, 09:10 UTCJul 5, 09:25 UTC15m
2026-07-05 N557PC - Jul 5, 04:50 UTCJul 5, 05:05 UTC15m
2026-07-05 N557PC - Jul 5, 03:00 UTCJul 5, 03:10 UTC10m
2026-07-05 N557PC - Jul 5, 00:05 UTCJul 5, 00:25 UTC20m
2026-07-04 N557PC - Jul 4, 21:15 UTCJul 4, 21:30 UTC15m
2026-07-04 N557PC - Jul 4, 12:05 UTCJul 4, 12:20 UTC15m
2026-07-04 N557PC - Jul 4, 02:55 UTCJul 4, 03:15 UTC20m
2026-07-04 N557PC - Jul 4, 00:30 UTCJul 4, 00:45 UTC15m
2026-07-03 N557PC - Jul 3, 06:10 UTCJul 3, 06:30 UTC20m
2026-07-03 N557PC - Jul 3, 04:35 UTCJul 3, 04:50 UTC15m
2026-07-02 N557PC - Jul 2, 11:45 UTCJul 2, 12:20 UTC35m
2026-07-02 N557PC - Jul 2, 09:30 UTCJul 2, 10:00 UTC30m
2026-07-01 N557PC - Jul 1, 16:40 UTCJul 1, 17:25 UTC45m
2026-07-01 N557PC - Jul 1, 03:10 UTCJul 1, 03:55 UTC45m
2026-06-28 N557PC - Jun 28, 02:14 UTCJun 28, 02:34 UTC20m
2026-06-27 N557PC - Jun 27, 23:29 UTCJun 27, 23:45 UTC15m
2026-06-27 N557PC - Jun 27, 13:20 UTCJun 27, 13:40 UTC20m
2026-06-27 N557PC - Jun 27, 11:25 UTCJun 27, 11:39 UTC15m
2026-06-27 N557PC - Jun 27, 08:20 UTCJun 27, 08:35 UTC15m
2026-06-27 N557PC - Jun 27, 06:44 UTCJun 27, 06:54 UTC10m
2026-06-27 N557PC - Jun 27, 04:39 UTCJun 27, 05:04 UTC25m
2026-06-27 N557PC - Jun 27, 02:09 UTCJun 27, 02:29 UTC20m
2026-06-26 N557PC - Jun 26, 20:24 UTCJun 26, 20:44 UTC20m
2026-06-26 N557PC - Jun 26, 17:29 UTCJun 26, 17:40 UTC10m
2026-06-24 N557PC - Jun 24, 20:14 UTCJun 24, 20:35 UTC20m
2026-06-24 N557PC - Jun 24, 17:34 UTCJun 24, 17:50 UTC15m
2026-06-24 N557PC - Jun 24, 08:39 UTCJun 24, 09:39 UTC1h 0m
2026-06-24 N557PC - Jun 24, 05:20 UTCJun 24, 06:29 UTC1h 10m
2026-06-24 N557PC - Jun 24, 03:19 UTCJun 24, 03:40 UTC20m
2026-06-23 N557PC - Jun 23, 02:49 UTCJun 23, 03:49 UTC1h 0m
2026-06-22 N557PC - Jun 22, 23:39 UTCJun 23, 00:45 UTC1h 5m
2026-06-22 N557PC - Jun 22, 15:45 UTCJun 22, 15:59 UTC15m
2026-06-22 N557PC - Jun 22, 13:05 UTCJun 22, 13:19 UTC15m
2026-06-22 N557PC - Jun 22, 04:30 UTCJun 22, 04:44 UTC15m
2026-06-22 N557PC - Jun 22, 02:10 UTCJun 22, 02:19 UTC10m
2026-06-20 N557PC - Jun 20, 11:34 UTCJun 20, 11:44 UTC10m

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 N557PC page for operator, model, and routing details .

Mode-S A71AB4 frequently asked

What is Mode-S code A71AB4?
A71AB4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N557PC.
Where is Mode-S A71AB4 registered?
Mode-S code A71AB4 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 A71AB4 broadcasting right now?
No active broadcast right now. Last signal was 6d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A71AB4, octal 51615264, decimal 10,951,348.
What flights does A71AB4 operate?
Mode-S A71AB4 has broadcast 1 distinct callsign, including N557PC.