sensors Mode-S transponder

A661FC

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N510FR · GULFSTREAM 2 · operated by ONEFLIGHT INTERNATIONAL INC

Hex
A661FC
Octal
51460774
Decimal
10,904,060
Country
US
Tail
N510FR
Type
GLF2
No current signal · last broadcast 8d ago
Flights observed
50
Distinct callsigns
1
Country
US
Last broadcast
8d ago

Last known position

Most recent position reported by Mode-S A661FC.

Country allocation

The ICAO 24-bit address A661FC 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
N510FR - 50 2026-07-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-21 N510FR - Jul 21, 01:30 UTCJul 21, 05:00 UTC3h 30m
2026-07-20 N510FR - Jul 20, 21:50 UTCJul 21, 00:25 UTC2h 34m
2026-07-20 N510FR IAD → TEB Jul 20, 17:50 UTCJul 20, 18:40 UTC50m
2026-07-19 N510FR - Jul 19, 16:20 UTCJul 19, 16:55 UTC35m
2026-07-19 N510FR - Jul 19, 14:15 UTCJul 19, 15:45 UTC1h 30m
2026-07-18 N510FR - Jul 18, 18:20 UTCJul 18, 19:30 UTC1h 10m
2026-07-18 N510FR - Jul 18, 15:00 UTCJul 18, 17:15 UTC2h 15m
2026-07-17 N510FR TEB → FLL Jul 17, 18:19 UTCJul 17, 20:35 UTC2h 15m
2026-07-17 N510FR - Jul 17, 14:10 UTCJul 17, 16:34 UTC2h 25m
2026-07-16 N510FR - Jul 16, 18:34 UTCJul 16, 22:10 UTC3h 35m
2026-07-15 N510FR - Jul 15, 19:00 UTCJul 15, 21:25 UTC2h 25m
2026-07-15 N510FR - Jul 15, 12:55 UTCJul 15, 17:50 UTC4h 55m
2026-07-15 N510FR - Jul 15, 10:35 UTCJul 15, 11:40 UTC1h 5m
2026-07-13 N510FR - Jul 13, 14:15 UTCJul 13, 16:25 UTC2h 10m
2026-07-12 N510FR - Jul 12, 19:15 UTCJul 12, 21:05 UTC1h 50m
2026-07-09 N510FR - Jul 9, 22:25 UTCJul 10, 00:40 UTC2h 15m
2026-07-09 N510FR - Jul 9, 18:20 UTCJul 9, 21:40 UTC3h 20m
2026-07-09 N510FR - Jul 9, 15:15 UTCJul 9, 17:05 UTC1h 50m
2026-07-07 N510FR STP → APA Jul 7, 21:00 UTCJul 7, 22:50 UTC1h 50m
2026-07-07 N510FR - Jul 7, 15:25 UTCJul 7, 18:40 UTC3h 15m
2026-07-02 N510FR - Jul 2, 14:25 UTCJul 2, 15:35 UTC1h 10m
2026-07-01 N510FR - Jul 1, 22:45 UTCJul 1, 23:55 UTC1h 10m
2026-07-01 N510FR - Jul 1, 19:35 UTCJul 1, 20:05 UTC30m
2026-07-01 N510FR - Jul 1, 14:50 UTCJul 1, 18:10 UTC3h 20m
2026-06-30 N510FR - Jun 30, 18:35 UTCJun 30, 20:10 UTC1h 35m
2026-06-28 N510FR - Jun 28, 14:19 UTCJun 28, 14:50 UTC30m
2026-06-28 N510FR - Jun 28, 14:04 UTCJun 28, 14:14 UTC10m
2026-06-28 N510FR APA → APA Jun 28, 13:34 UTCJun 28, 13:40 UTC5m
2026-06-22 N510FR - Jun 22, 20:10 UTCJun 22, 21:49 UTC1h 40m
2026-06-22 N510FR - Jun 22, 17:15 UTCJun 22, 19:34 UTC2h 20m
2026-06-22 N510FR - Jun 22, 14:24 UTCJun 22, 15:54 UTC1h 30m
2026-06-15 N510FR VNY → APA Jun 15, 21:40 UTCJun 15, 23:19 UTC1h 40m
2026-06-15 N510FR APA → VNY Jun 15, 19:00 UTCJun 15, 20:50 UTC1h 50m
2026-06-15 N510FR VNY → APA Jun 15, 01:04 UTCJun 15, 02:44 UTC1h 40m
2026-06-14 N510FR APA → VNY Jun 14, 22:00 UTCJun 14, 23:59 UTC1h 59m
2026-05-20 N510FR TEB → APA May 20, 12:40 UTCMay 20, 16:30 UTC3h 50m
2026-05-18 N510FR APA → TEB May 18, 14:40 UTCMay 18, 17:45 UTC3h 5m
2026-05-10 N510FR - May 10, 22:49 UTCMay 11, 02:00 UTC3h 10m
2026-05-07 N510FR - May 7, 16:25 UTCMay 7, 17:50 UTC1h 25m
2026-05-07 N510FR - May 7, 13:35 UTCMay 7, 14:45 UTC1h 10m
2026-05-05 N510FR - May 5, 19:30 UTCMay 5, 19:55 UTC25m
2026-05-05 N510FR - May 5, 16:35 UTCMay 5, 17:05 UTC30m
2026-05-04 N510FR - May 4, 19:00 UTCMay 4, 22:35 UTC3h 35m
2026-05-04 N510FR - May 4, 15:00 UTCMay 4, 17:20 UTC2h 20m
2026-05-03 N510FR - May 3, 23:39 UTCMay 4, 03:40 UTC4h 0m
2026-04-30 N510FR - Apr 30, 15:05 UTCApr 30, 18:05 UTC3h 0m
2026-04-29 N510FR - Apr 29, 15:15 UTCApr 29, 16:15 UTC1h 0m
2026-04-27 N510FR APA → APA Apr 27, 20:40 UTCApr 27, 22:15 UTC1h 35m
2026-04-24 N510FR - Apr 24, 17:45 UTCApr 24, 18:25 UTC40m
2026-04-23 N510FR - Apr 23, 18:00 UTCApr 23, 20:45 UTC2h 45m

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 N510FR page for operator, model, and routing details .

Mode-S A661FC frequently asked

What is Mode-S code A661FC?
A661FC is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N510FR.
Where is Mode-S A661FC registered?
Mode-S code A661FC 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 A661FC broadcasting right now?
No active broadcast right now. Last signal was 8d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A661FC, octal 51460774, decimal 10,904,060.
What flights does A661FC operate?
Mode-S A661FC has broadcast 1 distinct callsign, including N510FR.