Apparatus

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sensors Mode-S transponder

A77D4C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N58191 · HUGHES 500 · operated by TEMSCO HELICOPTERS INC

Hex
A77D4C
Octal
51676514
Decimal
10,976,588
Country
US
Tail
N58191
Type
H500
No current signal · last broadcast 2d ago
Flights observed
49
Distinct callsigns
1
Country
US
Last broadcast
2d ago

Last known position

Most recent position reported by Mode-S A77D4C.

Country allocation

The ICAO 24-bit address A77D4C 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
N58191 - 49 2026-07-12

Recent flights last 49

DateFlightRouteTakeoffLandingDuration
2026-07-12 N58191 - Jul 12, 00:55 UTCJul 12, 01:15 UTC20m
2026-07-11 N58191 - Jul 11, 23:00 UTCJul 11, 23:45 UTC45m
2026-07-11 N58191 - Jul 11, 21:10 UTCJul 11, 21:35 UTC25m
2026-07-11 N58191 - Jul 11, 20:30 UTCJul 11, 20:55 UTC25m
2026-07-11 N58191 - Jul 11, 19:00 UTCJul 11, 19:40 UTC40m
2026-07-11 N58191 - Jul 11, 17:05 UTCJul 11, 17:35 UTC30m
2026-07-11 N58191 - Jul 11, 00:55 UTCJul 11, 01:35 UTC40m
2026-07-11 N58191 - Jul 11, 00:35 UTCJul 11, 00:45 UTC10m
2026-07-10 N58191 - Jul 10, 21:45 UTCJul 10, 22:45 UTC1h 0m
2026-07-10 N58191 - Jul 10, 20:50 UTCJul 10, 21:00 UTC10m
2026-07-10 N58191 - Jul 10, 17:55 UTCJul 10, 19:35 UTC1h 40m
2026-07-10 N58191 - Jul 10, 17:05 UTCJul 10, 17:25 UTC20m
2026-07-10 N58191 - Jul 10, 16:50 UTCJul 10, 17:00 UTC10m
2026-07-10 N58191 - Jul 10, 16:35 UTCJul 10, 16:45 UTC10m
2026-06-29 N58191 - Jun 29, 19:29 UTCJun 29, 19:54 UTC25m
2026-06-28 N58191 - Jun 28, 00:15 UTCJun 28, 00:55 UTC40m
2026-06-27 N58191 - Jun 27, 21:25 UTCJun 27, 21:50 UTC25m
2026-06-27 N58191 - Jun 27, 01:35 UTCJun 27, 02:45 UTC1h 10m
2026-06-26 N58191 - Jun 26, 23:39 UTCJun 27, 00:05 UTC25m
2026-06-26 N58191 - Jun 26, 21:45 UTCJun 26, 22:10 UTC25m
2026-06-26 N58191 - Jun 26, 17:29 UTCJun 26, 18:34 UTC1h 5m
2026-06-26 N58191 - Jun 26, 16:39 UTCJun 26, 16:54 UTC15m
2026-06-26 N58191 - Jun 26, 00:59 UTCJun 26, 02:54 UTC1h 55m
2026-06-25 N58191 - Jun 25, 21:25 UTCJun 25, 21:55 UTC30m
2026-06-25 N58191 - Jun 25, 17:30 UTCJun 25, 18:50 UTC1h 20m
2026-06-25 N58191 - Jun 25, 16:39 UTCJun 25, 16:59 UTC20m
2026-06-25 N58191 - Jun 25, 01:30 UTCJun 25, 01:54 UTC25m
2026-06-24 N58191 - Jun 24, 21:09 UTCJun 24, 21:50 UTC40m
2026-06-24 N58191 - Jun 24, 17:20 UTCJun 24, 17:45 UTC25m
2026-06-20 N58191 - Jun 20, 21:49 UTCJun 20, 22:14 UTC25m
2026-06-20 N58191 - Jun 20, 20:25 UTCJun 20, 20:29 UTC5m
2026-06-20 N58191 - Jun 20, 18:14 UTCJun 20, 19:15 UTC1h 0m
2026-06-19 N58191 - Jun 19, 19:54 UTCJun 19, 20:44 UTC50m
2026-06-19 N58191 - Jun 19, 17:29 UTCJun 19, 17:49 UTC20m
2026-06-17 N58191 - Jun 17, 17:00 UTCJun 17, 17:10 UTC10m
2026-06-16 N58191 - Jun 16, 17:10 UTCJun 16, 17:24 UTC15m
2026-06-15 N58191 - Jun 15, 23:35 UTCJun 15, 23:45 UTC10m
2026-06-05 N58191 - Jun 5, 22:15 UTCJun 5, 22:25 UTC10m
2026-06-03 N58191 - Jun 3, 22:25 UTCJun 3, 22:45 UTC20m
2026-06-03 N58191 - Jun 3, 20:25 UTCJun 3, 20:35 UTC10m
2026-06-03 N58191 - Jun 3, 19:20 UTCJun 3, 19:40 UTC20m
2026-05-28 N58191 - May 28, 23:10 UTCMay 28, 23:20 UTC10m
2026-05-28 N58191 - May 28, 22:00 UTCMay 28, 22:10 UTC10m
2026-05-28 N58191 - May 28, 20:05 UTCMay 28, 20:15 UTC10m
2026-05-26 N58191 - May 26, 01:55 UTCMay 26, 02:39 UTC45m
2026-05-26 N58191 - May 26, 00:24 UTCMay 26, 01:20 UTC55m
2026-05-25 N58191 - May 25, 20:09 UTCMay 25, 20:30 UTC20m
2026-05-18 N58191 - May 18, 23:45 UTCMay 19, 01:00 UTC1h 15m
2026-05-18 N58191 - May 18, 22:50 UTCMay 18, 23:00 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 N58191 page for operator, model, and routing details .

Mode-S A77D4C frequently asked

What is Mode-S code A77D4C?
A77D4C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N58191.
Where is Mode-S A77D4C registered?
Mode-S code A77D4C 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 A77D4C broadcasting right now?
No active broadcast right now. Last signal was 2d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A77D4C, octal 51676514, decimal 10,976,588.
What flights does A77D4C operate?
Mode-S A77D4C has broadcast 1 distinct callsign, including N58191.