sensors Mode-S transponder

0C21AA

ICAO 24-bit transponder address · allocated to Suriname

Hex
0C21AA
Octal
03020652
Decimal
795,050
Country
SR
No current signal · last broadcast 6d ago
Flights observed
4
Distinct callsigns
1
Country
SR
Last broadcast
6d ago

Last known position

Most recent position reported by Mode-S 0C21AA.

Country allocation

The ICAO 24-bit address 0C21AA falls within the block assigned to Suriname (SR) by ICAO Annex 10, Volume III. Every aircraft registered in Suriname 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
CIMRK - 4 2026-04-26

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-04-26 CIMRK - Apr 26, 16:40 UTCApr 26, 16:55 UTC15m
2026-04-26 CIMRK - Apr 26, 14:25 UTCApr 26, 14:40 UTC15m
2026-04-17 CIMRK - Apr 17, 22:30 UTCApr 17, 22:45 UTC15m
2026-04-17 CIMRK - Apr 17, 22:05 UTCApr 17, 22:25 UTC20m

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.

Mode-S 0C21AA frequently asked

What is Mode-S code 0C21AA?
0C21AA is an ICAO 24-bit transponder address. Allocated to Suriname.
Where is Mode-S 0C21AA registered?
Mode-S code 0C21AA is allocated to Suriname (SR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 0C21AA broadcasting right now?
No active broadcast right now. Last signal was 6d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 0C21AA, octal 03020652, decimal 795,050.
What flights does 0C21AA operate?
Mode-S 0C21AA has broadcast 1 distinct callsign, including CIMRK.