sensors Mode-S transponder

A4BF0F

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N40489 · operated by ROBINSON HELICOPTER CO

Hex
A4BF0F
Octal
51137417
Decimal
10,796,815
Country
US
Tail
N40489
No current signal · last broadcast Jul 24, 16:45 UTC
Flights observed
15
Distinct callsigns
1
Country
US
Last broadcast
Jul 24, 16:45 UTC

Last known position

Most recent position reported by Mode-S A4BF0F.

Country allocation

The ICAO 24-bit address A4BF0F 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
N40489 - 15 2026-07-24

Recent flights last 15

DateFlightRouteTakeoffLandingDuration
2026-07-24 N40489 - Jul 24, 15:50 UTCJul 24, 16:45 UTC55m
2026-07-18 N40489 - Jul 18, 16:30 UTCJul 18, 16:45 UTC15m
2026-07-18 N40489 - Jul 18, 13:55 UTCJul 18, 14:40 UTC45m
2026-07-14 N40489 - Jul 14, 15:10 UTCJul 14, 16:35 UTC1h 25m
2026-07-11 N40489 - Jul 11, 23:25 UTCJul 11, 23:35 UTC10m
2026-07-11 N40489 - Jul 11, 20:45 UTCJul 11, 21:05 UTC20m
2026-07-11 N40489 - Jul 11, 18:05 UTCJul 11, 18:45 UTC40m
2026-07-11 N40489 - Jul 11, 14:55 UTCJul 11, 15:25 UTC30m
2026-07-10 N40489 - Jul 10, 19:50 UTCJul 10, 21:40 UTC1h 50m
2026-07-10 N40489 - Jul 10, 16:55 UTCJul 10, 17:35 UTC40m
2026-06-23 N40489 - Jun 23, 14:10 UTCJun 23, 15:40 UTC1h 30m
2026-06-22 N40489 - Jun 22, 21:25 UTCJun 22, 21:59 UTC35m
2026-06-22 N40489 - Jun 22, 20:10 UTCJun 22, 20:49 UTC40m
2026-06-22 N40489 - Jun 22, 17:25 UTCJun 22, 17:34 UTC10m
2026-06-22 N40489 - Jun 22, 14:10 UTCJun 22, 14:49 UTC40m

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 N40489 page for operator, model, and routing details .

Mode-S A4BF0F frequently asked

What is Mode-S code A4BF0F?
A4BF0F is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N40489.
Where is Mode-S A4BF0F registered?
Mode-S code A4BF0F 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 A4BF0F broadcasting right now?
No active broadcast right now. Last signal was Jul 24, 16:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4BF0F, octal 51137417, decimal 10,796,815.
What flights does A4BF0F operate?
Mode-S A4BF0F has broadcast 1 distinct callsign, including N40489.