sensors Mode-S transponder

A8A012

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N655HX · operated by HELICOPTER EXPRESS LLC

Hex
A8A012
Octal
52120022
Decimal
11,051,026
Country
US
Tail
N655HX
No current signal · last broadcast 8d ago
Flights observed
12
Distinct callsigns
1
Country
US
Last broadcast
8d ago

Last known position

Most recent position reported by Mode-S A8A012.

Country allocation

The ICAO 24-bit address A8A012 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
N655HX - 12 2026-05-21

Recent flights last 12

DateFlightRouteTakeoffLandingDuration
2026-05-21 N655HX - May 21, 20:25 UTCMay 21, 20:35 UTC10m
2026-05-21 N655HX - May 21, 18:40 UTCMay 21, 19:00 UTC20m
2026-05-21 N655HX - May 21, 16:40 UTCMay 21, 18:05 UTC1h 25m
2026-05-20 N655HX MFR → MFR May 20, 22:50 UTCMay 20, 23:05 UTC15m
2026-05-20 N655HX MFR → MFR May 20, 17:10 UTCMay 20, 17:35 UTC25m
2026-05-18 N655HX - May 18, 00:35 UTCMay 18, 00:55 UTC20m
2026-05-17 N655HX - May 17, 23:20 UTCMay 17, 23:40 UTC20m
2026-05-16 N655HX MFR → MFR May 16, 23:15 UTCMay 17, 00:20 UTC1h 5m
2026-05-03 N655HX MFR → MFR May 3, 01:35 UTCMay 3, 01:45 UTC10m
2026-05-01 N655HX MFR → MFR May 1, 22:10 UTCMay 1, 23:15 UTC1h 5m
2026-04-29 N655HX MFR → MFR Apr 29, 22:10 UTCApr 30, 01:30 UTC3h 19m
2026-04-29 N655HX MFR → MFR Apr 29, 20:50 UTCApr 29, 21:25 UTC35m

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 N655HX page for operator, model, and routing details .

Mode-S A8A012 frequently asked

What is Mode-S code A8A012?
A8A012 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N655HX.
Where is Mode-S A8A012 registered?
Mode-S code A8A012 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 A8A012 broadcasting right now?
No active broadcast right now. Last signal was 8d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A8A012, octal 52120022, decimal 11,051,026.
What flights does A8A012 operate?
Mode-S A8A012 has broadcast 1 distinct callsign, including N655HX.