Apparatus

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sensors Mode-S transponder

A65FCB

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N51HF · CESSNA 206 Stationair · operated by SAN MATEO COUNTY SHERIFF'S OFFICE

Hex
A65FCB
Octal
51457713
Decimal
10,903,499
Country
US
Tail
N51HF
Type
C206
No current signal · last broadcast 8h ago
Flights observed
40
Distinct callsigns
1
Country
US
Last broadcast
8h ago

Last known position

Most recent position reported by Mode-S A65FCB.

Country allocation

The ICAO 24-bit address A65FCB 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
N51HF - 40 2026-07-17

Recent flights last 40

DateFlightRouteTakeoffLandingDuration
2026-07-17 N51HF SQL → SQL Jul 17, 21:30 UTCJul 17, 22:49 UTC1h 20m
2026-07-13 N51HF SQL → SQL Jul 13, 21:15 UTCJul 13, 22:45 UTC1h 30m
2026-07-13 N51HF SQL → SQL Jul 13, 19:40 UTCJul 13, 20:40 UTC1h 0m
2026-07-09 N51HF SQL → SQL Jul 9, 19:00 UTCJul 9, 23:10 UTC4h 10m
2026-07-06 N51HF SQL → SQL Jul 6, 22:15 UTCJul 7, 00:05 UTC1h 50m
2026-07-04 N51HF SQL → SQL Jul 4, 16:35 UTCJul 4, 19:40 UTC3h 5m
2026-07-02 N51HF SQL → SQL Jul 2, 02:10 UTCJul 2, 04:40 UTC2h 30m
2026-07-01 N51HF SQL → SQL Jul 1, 19:50 UTCJul 1, 22:55 UTC3h 5m
2026-06-30 N51HF SQL → SQL Jun 30, 20:15 UTCJun 30, 21:45 UTC1h 30m
2026-06-25 N51HF SQL → SQL Jun 25, 23:44 UTCJun 26, 01:34 UTC1h 50m
2026-06-23 N51HF SQL → SQL Jun 23, 20:15 UTCJun 23, 22:10 UTC1h 55m
2026-06-23 N51HF SQL → SQL Jun 23, 02:15 UTCJun 23, 04:09 UTC1h 55m
2026-06-20 N51HF SQL → SQL Jun 20, 03:44 UTCJun 20, 04:44 UTC1h 0m
2026-06-18 N51HF SQL → SQL Jun 18, 21:15 UTCJun 18, 23:00 UTC1h 45m
2026-06-17 N51HF SQL → SQL Jun 17, 21:00 UTCJun 17, 22:15 UTC1h 15m
2026-06-17 N51HF SQL → SQL Jun 17, 02:10 UTCJun 17, 04:00 UTC1h 50m
2026-06-16 N51HF SQL → SQL Jun 16, 20:35 UTCJun 16, 23:35 UTC3h 0m
2026-06-13 N51HF SQL → SQL Jun 13, 20:45 UTCJun 13, 22:20 UTC1h 35m
2026-06-13 N51HF SQL → SQL Jun 13, 17:00 UTCJun 13, 19:45 UTC2h 45m
2026-06-13 N51HF SQL → SQL Jun 13, 01:05 UTCJun 13, 01:20 UTC15m
2026-06-13 N51HF SQL → SQL Jun 13, 00:25 UTCJun 13, 01:00 UTC35m
2026-06-11 N51HF SQL → SQL Jun 11, 23:15 UTCJun 12, 00:00 UTC45m
2026-06-11 N51HF SQL → SQL Jun 11, 04:15 UTCJun 11, 05:35 UTC1h 20m
2026-06-09 N51HF SQL → SQL Jun 9, 23:45 UTCJun 10, 02:45 UTC3h 0m
2026-06-09 N51HF - Jun 9, 20:25 UTCJun 9, 20:30 UTC5m
2026-06-09 N51HF - Jun 9, 17:40 UTCJun 9, 19:30 UTC1h 50m
2026-06-04 N51HF SQL → SQL Jun 4, 18:50 UTCJun 4, 23:10 UTC4h 20m
2026-06-04 N51HF SQL → SQL Jun 4, 04:05 UTCJun 4, 05:30 UTC1h 25m
2026-06-03 N51HF SQL → SQL Jun 3, 20:40 UTCJun 3, 22:30 UTC1h 50m
2026-06-01 N51HF SQL → SQL Jun 1, 19:40 UTCJun 1, 21:35 UTC1h 55m
2026-05-28 N51HF SQL → SQL May 28, 18:50 UTCMay 28, 22:10 UTC3h 20m
2026-05-15 N51HF SQL → SQL May 15, 20:55 UTCMay 15, 22:45 UTC1h 50m
2026-05-12 N51HF SQL → SQL May 12, 20:05 UTCMay 12, 22:01 UTC1h 55m
2026-05-12 N51HF - May 12, 02:45 UTCMay 12, 03:10 UTC25m
2026-05-08 N51HF SQL → SQL May 8, 22:40 UTCMay 8, 23:30 UTC50m
2026-05-08 N51HF SQL → SQL May 8, 20:20 UTCMay 8, 20:25 UTC5m
2026-05-08 N51HF - May 8, 20:05 UTCMay 8, 20:15 UTC10m
2026-05-08 N51HF SQL → SQL May 8, 19:25 UTCMay 8, 20:00 UTC35m
2026-05-05 N51HF - May 5, 19:10 UTCMay 5, 19:25 UTC15m
2026-05-04 N51HF SQL → RHV May 4, 20:40 UTCMay 4, 20:55 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 N51HF page for operator, model, and routing details .

Mode-S A65FCB frequently asked

What is Mode-S code A65FCB?
A65FCB is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N51HF.
Where is Mode-S A65FCB registered?
Mode-S code A65FCB 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 A65FCB broadcasting right now?
No active broadcast right now. Last signal was 8h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A65FCB, octal 51457713, decimal 10,903,499.
What flights does A65FCB operate?
Mode-S A65FCB has broadcast 1 distinct callsign, including N51HF.