sensors Mode-S transponder

0C21B8

ICAO 24-bit transponder address · allocated to Suriname

Currently assigned to HP-9810CMP · BOEING 737 MAX 8

Hex
0C21B8
Octal
03020670
Decimal
795,064
Country
SR
Tail
HP-9810CMP
Type
B38M
No current signal · last broadcast 1d ago
Flights observed
7
Distinct callsigns
2
Country
SR
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 0C21B8.

Country allocation

The ICAO 24-bit address 0C21B8 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 2 distinct

Callsign Airline Flights Last seen
CMP253 - 4 2026-04-13
CMP456 Copa Airlines 3 2026-04-13

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 CMP253 - Apr 13, 12:40 UTCApr 13, 12:55 UTC15m
2026-04-13 CMP253 - Apr 13, 11:55 UTCApr 13, 12:55 UTC1h 0m
2026-04-13 CMP253 - Apr 13, 08:20 UTCApr 13, 12:15 UTC3h 55m
2026-04-13 CMP253 - Apr 13, 08:00 UTCApr 13, 08:15 UTC15m
2026-04-13 CMP456 PTY → LAS Apr 13, 04:20 UTCApr 13, 05:25 UTC1h 5m
2026-04-13 CMP456 PTY → LAS Apr 13, 03:55 UTCApr 13, 05:25 UTC1h 30m
2026-04-13 CMP456 PTY → LAS Apr 13, 00:20 UTCApr 13, 04:15 UTC3h 55m

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 HP-9810CMP page for operator, model, and routing details .

Mode-S 0C21B8 frequently asked

What is Mode-S code 0C21B8?
0C21B8 is an ICAO 24-bit transponder address. Allocated to Suriname. Assigned to HP-9810CMP.
Where is Mode-S 0C21B8 registered?
Mode-S code 0C21B8 is allocated to Suriname (SR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 0C21B8 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 0C21B8, octal 03020670, decimal 795,064.
What flights does 0C21B8 operate?
Mode-S 0C21B8 has broadcast 2 distinct callsigns, including CMP253, CMP456.