sensors Mode-S transponder

A420A4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N365UC · AIRBUS HELICOPTERS EC-145 · operated by AIR METHODS LLC

Hex
A420A4
Octal
51020244
Decimal
10,756,260
Country
US
Tail
N365UC
Type
EC45
No current signal · last broadcast 15h ago
Flights observed
81
Distinct callsigns
1
Country
US
Last broadcast
15h ago

Last known position

Most recent position reported by Mode-S A420A4.

Country allocation

The ICAO 24-bit address A420A4 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
N365UC - 81 2026-05-29

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 N365UC - May 29, 19:05 UTCMay 29, 19:15 UTC10m
2026-05-29 N365UC - May 29, 16:05 UTCMay 29, 16:35 UTC30m
2026-05-29 N365UC - May 29, 14:40 UTCMay 29, 15:05 UTC25m
2026-05-28 N365UC - May 28, 23:30 UTCMay 28, 23:40 UTC10m
2026-05-28 N365UC - May 28, 21:20 UTCMay 28, 21:30 UTC10m
2026-05-28 N365UC - May 28, 08:10 UTCMay 28, 08:20 UTC10m
2026-05-28 N365UC - May 28, 03:45 UTCMay 28, 03:55 UTC10m
2026-05-27 N365UC - May 27, 17:45 UTCMay 27, 18:00 UTC15m
2026-05-27 N365UC - May 27, 00:49 UTCMay 27, 02:09 UTC1h 20m
2026-05-26 N365UC - May 26, 22:29 UTCMay 26, 22:59 UTC30m
2026-05-26 N365UC - May 26, 21:25 UTCMay 26, 21:49 UTC25m
2026-05-26 N365UC - May 26, 20:29 UTCMay 26, 20:50 UTC20m
2026-05-26 N365UC - May 26, 19:05 UTCMay 26, 19:50 UTC45m
2026-05-26 N365UC - May 26, 17:20 UTCMay 26, 17:25 UTC5m
2026-05-26 N365UC - May 26, 13:54 UTCMay 26, 14:05 UTC10m
2026-05-26 N365UC - May 26, 06:10 UTCMay 26, 06:25 UTC15m
2026-05-26 N365UC - May 26, 03:15 UTCMay 26, 05:40 UTC2h 25m
2026-05-26 N365UC - May 26, 02:15 UTCMay 26, 02:35 UTC20m
2026-05-26 N365UC - May 26, 01:05 UTCMay 26, 01:24 UTC20m
2026-05-25 N365UC - May 25, 22:40 UTCMay 25, 23:54 UTC1h 15m
2026-05-25 N365UC - May 25, 20:55 UTCMay 25, 21:45 UTC50m
2026-05-25 N365UC - May 25, 02:05 UTCMay 25, 02:15 UTC10m
2026-05-24 N365UC - May 24, 23:00 UTCMay 24, 23:46 UTC46m
2026-05-24 N365UC - May 24, 18:30 UTCMay 24, 18:40 UTC10m
2026-05-23 N365UC - May 23, 00:45 UTCMay 23, 01:50 UTC1h 5m
2026-05-22 N365UC - May 22, 16:05 UTCMay 22, 16:25 UTC20m
2026-05-22 N365UC - May 22, 15:10 UTCMay 22, 15:30 UTC20m
2026-05-22 N365UC - May 22, 14:10 UTCMay 22, 14:20 UTC10m
2026-05-21 N365UC - May 21, 22:20 UTCMay 21, 23:25 UTC1h 5m
2026-05-21 N365UC - May 21, 21:15 UTCMay 21, 21:25 UTC10m
2026-05-21 N365UC - May 21, 14:55 UTCMay 21, 15:35 UTC40m
2026-05-20 N365UC - May 20, 18:15 UTCMay 20, 18:30 UTC15m
2026-05-20 N365UC - May 20, 02:40 UTCMay 20, 03:05 UTC25m
2026-05-19 N365UC - May 19, 01:35 UTCMay 19, 02:00 UTC25m
2026-05-18 N365UC - May 18, 23:25 UTCMay 19, 00:40 UTC1h 15m
2026-05-17 N365UC - May 17, 22:01 UTCMay 17, 22:10 UTC10m
2026-05-17 N365UC - May 17, 19:55 UTCMay 17, 20:40 UTC45m
2026-05-17 N365UC - May 17, 18:20 UTCMay 17, 18:30 UTC10m
2026-05-17 N365UC - May 17, 17:25 UTCMay 17, 17:35 UTC10m
2026-05-17 N365UC - May 17, 15:50 UTCMay 17, 16:01 UTC10m
2026-05-17 N365UC - May 17, 13:45 UTCMay 17, 14:15 UTC30m
2026-05-17 N365UC - May 17, 12:20 UTCMay 17, 12:45 UTC25m
2026-05-16 N365UC - May 16, 18:05 UTCMay 16, 18:15 UTC10m
2026-05-16 N365UC - May 16, 17:01 UTCMay 16, 17:15 UTC15m
2026-05-16 N365UC - May 16, 14:55 UTCMay 16, 15:35 UTC40m
2026-05-16 N365UC - May 16, 00:40 UTCMay 16, 01:10 UTC30m
2026-05-15 N365UC - May 15, 22:40 UTCMay 16, 00:00 UTC1h 20m
2026-05-15 N365UC - May 15, 21:05 UTCMay 15, 21:15 UTC10m
2026-05-15 N365UC - May 15, 20:35 UTCMay 15, 20:55 UTC20m
2026-05-15 N365UC - May 15, 06:45 UTCMay 15, 06:55 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 N365UC page for operator, model, and routing details .

Mode-S A420A4 frequently asked

What is Mode-S code A420A4?
A420A4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N365UC.
Where is Mode-S A420A4 registered?
Mode-S code A420A4 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 A420A4 broadcasting right now?
No active broadcast right now. Last signal was 15h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A420A4, octal 51020244, decimal 10,756,260.
What flights does A420A4 operate?
Mode-S A420A4 has broadcast 1 distinct callsign, including N365UC.