sensors Mode-S transponder

4851AF

ICAO 24-bit transponder address · allocated to Netherlands

Currently assigned to PH-BHD · BOEING 787-9 Dreamliner

Hex
4851AF
Octal
22050657
Decimal
4,739,503
Country
NL
Tail
PH-BHD
Type
B789
Photo of PH-BHD
No current signal · last broadcast 12h ago
Flights observed
5
Distinct callsigns
2
Country
NL
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 4851AF.

Country allocation

The ICAO 24-bit address 4851AF falls within the block assigned to Netherlands (NL) by ICAO Annex 10, Volume III. Every aircraft registered in Netherlands 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 2 distinct

Callsign Airline Flights Last seen
KLM759 KLM Royal Dutch Airlines 4 2026-04-13
KLM760 - 1 2026-04-14

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-14 KLM760 - Apr 14, 09:10 UTCApr 14, 10:30 UTC1h 20m
2026-04-13 KLM759 AMS → SJO Apr 13, 21:25 UTCApr 13, 22:00 UTC35m
2026-04-13 KLM759 AMS → SJO Apr 13, 12:20 UTCApr 13, 13:10 UTC50m
2026-04-13 KLM759 AMS → SJO Apr 13, 11:55 UTCApr 13, 13:10 UTC1h 15m
2026-04-13 KLM759 AMS → SJO Apr 13, 11:30 UTCApr 13, 12:15 UTC45m

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 PH-BHD page for operator, model, and routing details .

Mode-S 4851AF frequently asked

What is Mode-S code 4851AF?
4851AF is an ICAO 24-bit transponder address. Allocated to Netherlands. Assigned to PH-BHD.
Where is Mode-S 4851AF registered?
Mode-S code 4851AF is allocated to Netherlands (NL). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4851AF broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4851AF, octal 22050657, decimal 4,739,503.
What flights does 4851AF operate?
Mode-S 4851AF has broadcast 2 distinct callsigns, including KLM759, KLM760.