sensors Mode-S transponder

0C21D6

ICAO 24-bit transponder address · allocated to Suriname

Currently assigned to HP18BLM · BEECH 90 King Air

Hex
0C21D6
Octal
03020726
Decimal
795,094
Country
SR
Tail
HP18BLM
Type
BE9L
No current signal · last broadcast Jul 24, 18:25 UTC
Flights observed
4
Distinct callsigns
1
Country
SR
Last broadcast
Jul 24, 18:25 UTC

Last known position

Most recent position reported by Mode-S 0C21D6.

Country allocation

The ICAO 24-bit address 0C21D6 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
HP18BLM - 4 2026-07-24

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-07-24 HP18BLM - Jul 24, 18:10 UTCJul 24, 18:25 UTC15m
2026-07-24 HP18BLM - Jul 24, 12:50 UTCJul 24, 13:15 UTC25m
2026-04-27 HP18BLM - Apr 27, 22:00 UTCApr 27, 22:15 UTC15m
2026-04-27 HP18BLM - Apr 27, 19:10 UTCApr 27, 19:25 UTC15m

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 HP18BLM page for operator, model, and routing details .

Mode-S 0C21D6 frequently asked

What is Mode-S code 0C21D6?
0C21D6 is an ICAO 24-bit transponder address. Allocated to Suriname. Assigned to HP18BLM.
Where is Mode-S 0C21D6 registered?
Mode-S code 0C21D6 is allocated to Suriname (SR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 0C21D6 broadcasting right now?
No active broadcast right now. Last signal was Jul 24, 18:25 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 0C21D6, octal 03020726, decimal 795,094.
What flights does 0C21D6 operate?
Mode-S 0C21D6 has broadcast 1 distinct callsign, including HP18BLM.