sensors Mode-S transponder

4B4126

ICAO 24-bit transponder address · allocated to Switzerland

Currently assigned to HB-YRM · VANS RV-7

Hex
4B4126
Octal
22640446
Decimal
4,931,878
Country
CH
Tail
HB-YRM
Type
RV7
No current signal · last broadcast 13h ago
Flights observed
3
Distinct callsigns
1
Country
CH
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S 4B4126.

Country allocation

The ICAO 24-bit address 4B4126 falls within the block assigned to Switzerland (CH) by ICAO Annex 10, Volume III. Every aircraft registered in Switzerland 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
HBYRM - 3 2026-04-18

Recent flights last 3

DateFlightRouteTakeoffLandingDuration
2026-04-18 HBYRM - Apr 18, 12:15 UTCApr 18, 12:40 UTC25m
2026-04-18 HBYRM - Apr 18, 11:05 UTCApr 18, 11:35 UTC30m
2026-04-16 HBYRM - Apr 16, 09:15 UTCApr 16, 10:05 UTC50m

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 HB-YRM page for operator, model, and routing details .

Mode-S 4B4126 frequently asked

What is Mode-S code 4B4126?
4B4126 is an ICAO 24-bit transponder address. Allocated to Switzerland. Assigned to HB-YRM.
Where is Mode-S 4B4126 registered?
Mode-S code 4B4126 is allocated to Switzerland (CH). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4B4126 broadcasting right now?
No active broadcast right now. Last signal was 13h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4B4126, octal 22640446, decimal 4,931,878.
What flights does 4B4126 operate?
Mode-S 4B4126 has broadcast 1 distinct callsign, including HBYRM.