Apparatus

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sensors Mode-S transponder

AB73F9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N837SP · CESSNA 172 Skyhawk · operated by ISRANI VIJAY

Hex
AB73F9
Octal
52671771
Decimal
11,236,345
Country
US
Tail
N837SP
Type
C172
No current signal · last broadcast 8h ago
Flights observed
162
Distinct callsigns
1
Country
US
Last broadcast
8h ago

Last known position

Most recent position reported by Mode-S AB73F9.

Country allocation

The ICAO 24-bit address AB73F9 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
N837SP - 162 2026-07-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 N837SP PAO → PAO Jul 14, 01:45 UTCJul 14, 02:25 UTC40m
2026-07-13 N837SP PAO → PAO Jul 13, 15:05 UTCJul 13, 15:20 UTC15m
2026-07-13 N837SP PAO → PAO Jul 13, 02:10 UTCJul 13, 03:20 UTC1h 10m
2026-07-12 N837SP PAO → PAO Jul 12, 20:10 UTCJul 12, 21:35 UTC1h 25m
2026-07-11 N837SP PAO → PAO Jul 11, 22:55 UTCJul 12, 00:30 UTC1h 35m
2026-07-11 N837SP PAO → PAO Jul 11, 19:25 UTCJul 11, 20:55 UTC1h 30m
2026-07-11 N837SP PAO → PAO Jul 11, 16:35 UTCJul 11, 17:40 UTC1h 5m
2026-07-09 N837SP PAO → PAO Jul 9, 20:30 UTCJul 9, 21:10 UTC40m
2026-07-07 N837SP PAO → PAO Jul 7, 23:20 UTCJul 8, 00:05 UTC45m
2026-07-06 N837SP PAO → PAO Jul 6, 23:15 UTCJul 7, 00:40 UTC1h 25m
2026-07-06 N837SP PAO → PAO Jul 6, 18:30 UTCJul 6, 20:15 UTC1h 45m
2026-07-03 N837SP PAO → PAO Jul 3, 18:50 UTCJul 3, 20:25 UTC1h 35m
2026-07-02 N837SP PAO → PAO Jul 2, 18:55 UTCJul 2, 20:30 UTC1h 35m
2026-07-01 N837SP PAO → PAO Jul 1, 19:55 UTCJul 1, 21:35 UTC1h 40m
2026-07-01 N837SP PAO → PAO Jul 1, 02:40 UTCJul 1, 03:45 UTC1h 5m
2026-06-30 N837SP PAO → PAO Jun 30, 22:35 UTCJul 1, 00:45 UTC2h 10m
2026-06-30 N837SP PAO → PAO Jun 30, 19:35 UTCJun 30, 21:20 UTC1h 45m
2026-06-30 N837SP PAO → PAO Jun 30, 01:25 UTCJun 30, 02:40 UTC1h 15m
2026-06-28 N837SP PAO → PAO Jun 28, 22:20 UTCJun 28, 23:25 UTC1h 5m
2026-06-28 N837SP PAO → PAO Jun 28, 19:44 UTCJun 28, 21:10 UTC1h 25m
2026-06-28 N837SP PAO → PAO Jun 28, 16:39 UTCJun 28, 18:00 UTC1h 20m
2026-06-27 N837SP PAO → PAO Jun 27, 22:29 UTCJun 27, 23:50 UTC1h 20m
2026-06-27 N837SP PAO → PAO Jun 27, 01:15 UTCJun 27, 02:35 UTC1h 20m
2026-06-26 N837SP PAO → PAO Jun 26, 20:55 UTCJun 26, 21:59 UTC1h 5m
2026-06-25 N837SP PAO → PAO Jun 25, 20:34 UTCJun 25, 22:20 UTC1h 45m
2026-06-24 N837SP PAO → PAO Jun 24, 17:10 UTCJun 24, 18:20 UTC1h 10m
2026-06-23 N837SP PAO → PAO Jun 23, 22:19 UTCJun 23, 23:50 UTC1h 30m
2026-06-23 N837SP PAO → PAO Jun 23, 19:39 UTCJun 23, 21:20 UTC1h 40m
2026-06-23 N837SP PAO → PAO Jun 23, 00:04 UTCJun 23, 00:50 UTC45m
2026-06-22 N837SP PAO → PAO Jun 22, 19:19 UTCJun 22, 20:39 UTC1h 20m
2026-06-21 N837SP - Jun 21, 20:40 UTCJun 21, 21:39 UTC1h 0m
2026-06-21 N837SP - Jun 21, 19:05 UTCJun 21, 20:09 UTC1h 5m
2026-06-20 N837SP PAO → PAO Jun 20, 20:55 UTCJun 20, 22:59 UTC2h 5m
2026-06-19 N837SP PAO → PAO Jun 19, 23:14 UTCJun 20, 00:34 UTC1h 20m
2026-06-19 N837SP PAO → PAO Jun 19, 20:49 UTCJun 19, 21:39 UTC50m
2026-06-19 N837SP PAO → PAO Jun 19, 16:55 UTCJun 19, 17:59 UTC1h 5m
2026-06-18 N837SP PAO → PAO Jun 18, 22:15 UTCJun 18, 23:45 UTC1h 30m
2026-06-18 N837SP PAO → PAO Jun 18, 19:25 UTCJun 18, 20:45 UTC1h 20m
2026-06-17 N837SP PAO → PAO Jun 17, 19:55 UTCJun 17, 21:00 UTC1h 5m
2026-06-17 N837SP PAO → PAO Jun 17, 01:10 UTCJun 17, 01:50 UTC40m
2026-06-16 N837SP PAO → PAO Jun 16, 19:40 UTCJun 16, 21:10 UTC1h 31m
2026-06-15 N837SP PAO → PAO Jun 15, 21:50 UTCJun 15, 23:39 UTC1h 50m
2026-06-15 N837SP PAO → PAO Jun 15, 17:59 UTCJun 15, 19:05 UTC1h 5m
2026-06-14 N837SP PAO → PAO Jun 14, 19:35 UTCJun 14, 20:55 UTC1h 20m
2026-06-14 N837SP PAO → PAO Jun 14, 00:50 UTCJun 14, 02:10 UTC1h 20m
2026-06-13 N837SP PAO → PAO Jun 13, 22:25 UTCJun 13, 23:50 UTC1h 25m
2026-06-13 N837SP PAO → PAO Jun 13, 17:40 UTCJun 13, 20:05 UTC2h 25m
2026-06-12 N837SP PAO → PAO Jun 12, 16:40 UTCJun 12, 20:05 UTC3h 25m
2026-06-11 N837SP PAO → PAO Jun 11, 19:40 UTCJun 11, 21:15 UTC1h 35m
2026-06-11 N837SP PAO → PAO Jun 11, 17:15 UTCJun 11, 18:40 UTC1h 25m

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 N837SP page for operator, model, and routing details .

Mode-S AB73F9 frequently asked

What is Mode-S code AB73F9?
AB73F9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N837SP.
Where is Mode-S AB73F9 registered?
Mode-S code AB73F9 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 AB73F9 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 AB73F9, octal 52671771, decimal 11,236,345.
What flights does AB73F9 operate?
Mode-S AB73F9 has broadcast 1 distinct callsign, including N837SP.