Apparatus

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sensors Mode-S transponder

A9C8EC

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N73CH · operated by ALF IX LLC

Hex
A9C8EC
Octal
52344354
Decimal
11,127,020
Country
US
Tail
N73CH
Type
C172
No current signal · last broadcast 5d ago
Flights observed
165
Distinct callsigns
1
Country
US
Last broadcast
5d ago

Last known position

Most recent position reported by Mode-S A9C8EC.

Country allocation

The ICAO 24-bit address A9C8EC 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
N73CH - 165 2026-07-15

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-15 N73CH DBQ → DBQ Jul 15, 18:35 UTCJul 15, 19:30 UTC55m
2026-07-15 N73CH DBQ → DBQ Jul 15, 17:10 UTCJul 15, 17:40 UTC30m
2026-07-14 N73CH DBQ → DBQ Jul 14, 19:40 UTCJul 14, 20:40 UTC1h 0m
2026-07-14 N73CH DBQ → DBQ Jul 14, 15:30 UTCJul 14, 16:35 UTC1h 5m
2026-07-13 N73CH DBQ → DBQ Jul 13, 21:25 UTCJul 13, 22:55 UTC1h 30m
2026-07-13 N73CH DBQ → DBQ Jul 13, 17:55 UTCJul 13, 20:15 UTC2h 20m
2026-07-13 N73CH - Jul 13, 13:45 UTCJul 13, 13:50 UTC5m
2026-07-13 N73CH - Jul 13, 12:35 UTCJul 13, 13:00 UTC25m
2026-07-11 N73CH BKX → DBQ Jul 11, 21:55 UTCJul 12, 00:40 UTC2h 45m
2026-07-11 N73CH - Jul 11, 16:00 UTCJul 11, 16:20 UTC20m
2026-07-11 N73CH - Jul 11, 13:40 UTCJul 11, 15:20 UTC1h 40m
2026-07-10 N73CH DBQ → DBQ Jul 10, 20:50 UTCJul 10, 21:30 UTC40m
2026-07-09 N73CH DBQ → DBQ Jul 9, 19:45 UTCJul 9, 20:45 UTC1h 0m
2026-07-09 N73CH DBQ → DBQ Jul 9, 17:15 UTCJul 9, 17:45 UTC30m
2026-07-09 N73CH DBQ → DBQ Jul 9, 15:15 UTCJul 9, 16:20 UTC1h 5m
2026-07-08 N73CH DBQ → DBQ Jul 8, 23:10 UTCJul 8, 23:15 UTC5m
2026-07-08 N73CH DBQ → DBQ Jul 8, 22:30 UTCJul 8, 22:35 UTC5m
2026-07-08 N73CH DBQ → DBQ Jul 8, 22:00 UTCJul 8, 22:25 UTC25m
2026-07-08 N73CH DBQ → DBQ Jul 8, 18:35 UTCJul 8, 20:30 UTC1h 55m
2026-07-08 N73CH DBQ → DBQ Jul 8, 16:40 UTCJul 8, 17:35 UTC55m
2026-07-08 N73CH DBQ → DBQ Jul 8, 14:35 UTCJul 8, 15:35 UTC1h 0m
2026-07-08 N73CH DBQ → DBQ Jul 8, 12:45 UTCJul 8, 13:40 UTC55m
2026-07-08 N73CH DBQ → DBQ Jul 8, 01:10 UTCJul 8, 02:05 UTC55m
2026-07-07 N73CH DBQ → DBQ Jul 7, 23:15 UTCJul 8, 00:15 UTC1h 0m
2026-07-07 N73CH - Jul 7, 20:50 UTCJul 7, 21:15 UTC25m
2026-07-07 N73CH - Jul 7, 20:15 UTCJul 7, 20:45 UTC30m
2026-07-07 N73CH - Jul 7, 18:20 UTCJul 7, 19:15 UTC55m
2026-07-07 N73CH - Jul 7, 17:25 UTCJul 7, 17:35 UTC10m
2026-07-07 N73CH - Jul 7, 16:05 UTCJul 7, 16:45 UTC40m
2026-07-07 N73CH DBQ → DBQ Jul 7, 14:15 UTCJul 7, 15:10 UTC55m
2026-07-07 N73CH DBQ → DBQ Jul 7, 12:30 UTCJul 7, 13:00 UTC30m
2026-07-02 N73CH - Jul 2, 17:10 UTCJul 2, 19:50 UTC2h 40m
2026-07-02 N73CH DBQ → IND Jul 2, 12:55 UTCJul 2, 15:10 UTC2h 15m
2026-07-01 N73CH DBQ → DBQ Jul 1, 21:50 UTCJul 1, 23:00 UTC1h 10m
2026-07-01 N73CH DBQ → DBQ Jul 1, 19:35 UTCJul 1, 20:40 UTC1h 5m
2026-07-01 N73CH DBQ → DBQ Jul 1, 17:15 UTCJul 1, 18:30 UTC1h 15m
2026-07-01 N73CH DBQ → DBQ Jul 1, 12:40 UTCJul 1, 13:55 UTC1h 15m
2026-07-01 N73CH DBQ → DBQ Jul 1, 02:05 UTCJul 1, 02:10 UTC5m
2026-07-01 N73CH DBQ → DBQ Jul 1, 01:50 UTCJul 1, 01:55 UTC5m
2026-07-01 N73CH DBQ → DBQ Jul 1, 01:15 UTCJul 1, 01:25 UTC10m
2026-07-01 N73CH DBQ → DBQ Jul 1, 00:50 UTCJul 1, 01:10 UTC20m
2026-06-30 N73CH DBQ → DBQ Jun 30, 20:00 UTCJun 30, 21:05 UTC1h 5m
2026-06-30 N73CH - Jun 30, 17:40 UTCJun 30, 18:45 UTC1h 5m
2026-06-30 N73CH - Jun 30, 16:45 UTCJun 30, 17:05 UTC20m
2026-06-30 N73CH - Jun 30, 12:40 UTCJun 30, 14:30 UTC1h 50m
2026-06-29 N73CH DBQ → DBQ Jun 29, 18:34 UTCJun 29, 19:49 UTC1h 15m
2026-06-29 N73CH DBQ → DBQ Jun 29, 15:49 UTCJun 29, 16:44 UTC55m
2026-06-27 N73CH DBQ → DBQ Jun 27, 02:45 UTCJun 27, 04:44 UTC2h 0m
2026-06-26 N73CH DBQ → DBQ Jun 26, 19:45 UTCJun 26, 20:50 UTC1h 5m
2026-06-26 N73CH DBQ → DBQ Jun 26, 17:29 UTCJun 26, 18:44 UTC1h 15m

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 N73CH page for operator, model, and routing details .

Mode-S A9C8EC frequently asked

What is Mode-S code A9C8EC?
A9C8EC is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N73CH.
Where is Mode-S A9C8EC registered?
Mode-S code A9C8EC 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 A9C8EC broadcasting right now?
No active broadcast right now. Last signal was 5d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A9C8EC, octal 52344354, decimal 11,127,020.
What flights does A9C8EC operate?
Mode-S A9C8EC has broadcast 1 distinct callsign, including N73CH.