sensors Mode-S transponder

505E77

ICAO 24-bit transponder address · allocated to Slovakia

Currently assigned to OM-M161 · TOMARK Viper

Hex
505E77
Octal
24057167
Decimal
5,267,063
Country
SK
Tail
OM-M161
Type
SD4
No current signal · last broadcast 1d ago
Flights observed
4
Distinct callsigns
1
Country
SK
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 505E77.

Country allocation

The ICAO 24-bit address 505E77 falls within the block assigned to Slovakia (SK) by ICAO Annex 10, Volume III. Every aircraft registered in Slovakia 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
OMM161 - 4 2026-04-13

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-04-13 OMM161 - Apr 13, 12:20 UTCApr 13, 13:15 UTC55m
2026-04-13 OMM161 - Apr 13, 11:55 UTCApr 13, 13:15 UTC1h 20m
2026-04-13 OMM161 - Apr 13, 10:00 UTCApr 13, 12:15 UTC2h 15m
2026-04-13 OMM161 - Apr 13, 05:45 UTCApr 13, 06:20 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 OM-M161 page for operator, model, and routing details .

Mode-S 505E77 frequently asked

What is Mode-S code 505E77?
505E77 is an ICAO 24-bit transponder address. Allocated to Slovakia. Assigned to OM-M161.
Where is Mode-S 505E77 registered?
Mode-S code 505E77 is allocated to Slovakia (SK). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 505E77 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 505E77, octal 24057167, decimal 5,267,063.
What flights does 505E77 operate?
Mode-S 505E77 has broadcast 1 distinct callsign, including OMM161.