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sensors Mode-S transponder

ADF79C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N99981 · CESSNA 172 Skyhawk · operated by SKY HIGH LEASING SERVICES LLC

Hex
ADF79C
Octal
53373634
Decimal
11,401,116
Country
US
Tail
N99981
Type
C172
No current signal · last broadcast 7h ago
Flights observed
162
Distinct callsigns
1
Country
US
Last broadcast
7h ago

Last known position

Most recent position reported by Mode-S ADF79C.

Country allocation

The ICAO 24-bit address ADF79C 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
N99981 - 162 2026-07-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 N99981 - Jul 14, 11:00 UTCJul 14, 11:35 UTC35m
2026-07-11 N99981 - Jul 11, 12:15 UTCJul 11, 14:15 UTC2h 0m
2026-07-10 N99981 - Jul 10, 12:10 UTCJul 10, 13:30 UTC1h 20m
2026-07-09 N99981 - Jul 9, 17:50 UTCJul 9, 18:15 UTC25m
2026-07-09 N99981 - Jul 9, 12:30 UTCJul 9, 13:35 UTC1h 5m
2026-07-08 N99981 - Jul 8, 16:10 UTCJul 8, 17:05 UTC55m
2026-07-08 N99981 - Jul 8, 13:05 UTCJul 8, 14:45 UTC1h 40m
2026-07-07 N99981 - Jul 7, 12:10 UTCJul 7, 14:10 UTC2h 0m
2026-07-06 N99981 - Jul 6, 14:05 UTCJul 6, 14:15 UTC10m
2026-07-06 N99981 - Jul 6, 12:55 UTCJul 6, 13:05 UTC10m
2026-07-05 N99981 - Jul 5, 14:15 UTCJul 5, 15:25 UTC1h 10m
2026-07-03 N99981 - Jul 3, 15:50 UTCJul 3, 17:20 UTC1h 30m
2026-07-03 N99981 - Jul 3, 12:15 UTCJul 3, 13:40 UTC1h 25m
2026-07-02 N99981 - Jul 2, 19:40 UTCJul 2, 21:00 UTC1h 20m
2026-07-02 N99981 - Jul 2, 18:10 UTCJul 2, 18:50 UTC40m
2026-07-02 N99981 - Jul 2, 14:15 UTCJul 2, 14:45 UTC30m
2026-07-02 N99981 - Jul 2, 12:30 UTCJul 2, 13:15 UTC45m
2026-06-29 N99981 - Jun 29, 12:20 UTCJun 29, 14:29 UTC2h 10m
2026-06-27 N99981 - Jun 27, 17:34 UTCJun 27, 18:45 UTC1h 10m
2026-06-27 N99981 - Jun 27, 11:44 UTCJun 27, 13:04 UTC1h 20m
2026-06-26 N99981 - Jun 26, 17:59 UTCJun 26, 19:04 UTC1h 5m
2026-06-26 N99981 - Jun 26, 15:15 UTCJun 26, 16:05 UTC50m
2026-06-26 N99981 - Jun 26, 11:49 UTCJun 26, 13:10 UTC1h 20m
2026-06-25 N99981 - Jun 25, 17:09 UTCJun 25, 17:25 UTC15m
2026-06-25 N99981 - Jun 25, 15:59 UTCJun 25, 16:14 UTC15m
2026-06-25 N99981 - Jun 25, 14:14 UTCJun 25, 15:15 UTC1h 0m
2026-06-25 N99981 - Jun 25, 11:50 UTCJun 25, 12:54 UTC1h 5m
2026-06-24 N99981 - Jun 24, 17:50 UTCJun 24, 18:55 UTC1h 5m
2026-06-24 N99981 - Jun 24, 13:34 UTCJun 24, 13:50 UTC15m
2026-06-24 N99981 - Jun 24, 12:25 UTCJun 24, 12:40 UTC15m
2026-06-23 N99981 - Jun 23, 20:19 UTCJun 23, 20:40 UTC20m
2026-06-23 N99981 - Jun 23, 17:04 UTCJun 23, 17:50 UTC45m
2026-06-23 N99981 - Jun 23, 13:00 UTCJun 23, 13:59 UTC1h 0m
2026-06-22 N99981 - Jun 22, 19:09 UTCJun 22, 20:30 UTC1h 20m
2026-06-22 N99981 - Jun 22, 15:54 UTCJun 22, 16:54 UTC1h 0m
2026-06-22 N99981 - Jun 22, 14:24 UTCJun 22, 14:40 UTC15m
2026-06-22 N99981 - Jun 22, 12:00 UTCJun 22, 13:49 UTC1h 50m
2026-06-21 N99981 - Jun 21, 13:34 UTCJun 21, 14:54 UTC1h 20m
2026-06-18 N99981 - Jun 18, 14:05 UTCJun 18, 15:05 UTC1h 0m
2026-06-18 N99981 - Jun 18, 12:20 UTCJun 18, 13:20 UTC1h 0m
2026-06-17 N99981 - Jun 17, 17:50 UTCJun 17, 18:56 UTC1h 5m
2026-06-17 N99981 - Jun 17, 12:05 UTCJun 17, 12:55 UTC50m
2026-06-16 N99981 - Jun 16, 11:55 UTCJun 16, 13:34 UTC1h 40m
2026-06-15 N99981 - Jun 15, 19:25 UTCJun 15, 19:39 UTC15m
2026-06-15 N99981 - Jun 15, 17:54 UTCJun 15, 18:29 UTC35m
2026-06-15 N99981 - Jun 15, 15:55 UTCJun 15, 16:30 UTC35m
2026-06-15 N99981 - Jun 15, 13:34 UTCJun 15, 14:30 UTC55m
2026-06-15 N99981 - Jun 15, 12:35 UTCJun 15, 13:00 UTC25m
2026-06-13 N99981 - Jun 13, 18:00 UTCJun 13, 18:25 UTC25m
2026-06-13 N99981 - Jun 13, 14:05 UTCJun 13, 14:15 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 N99981 page for operator, model, and routing details .

Mode-S ADF79C frequently asked

What is Mode-S code ADF79C?
ADF79C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N99981.
Where is Mode-S ADF79C registered?
Mode-S code ADF79C 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 ADF79C broadcasting right now?
No active broadcast right now. Last signal was 7h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex ADF79C, octal 53373634, decimal 11,401,116.
What flights does ADF79C operate?
Mode-S ADF79C has broadcast 1 distinct callsign, including N99981.