sensors Mode-S transponder

C021A4

ICAO 24-bit transponder address · allocated to Canada

Currently assigned to C-FMTF · CESSNA 172 Skyhawk · operated by Calgary Flying Club

Hex
C021A4
Octal
60020644
Decimal
12,591,524
Country
CA
Tail
C-FMTF
Type
C172
No current signal · last broadcast 22h ago
Flights observed
4
Distinct callsigns
1
Country
CA
Last broadcast
22h ago

Last known position

Most recent position reported by Mode-S C021A4.

Country allocation

The ICAO 24-bit address C021A4 falls within the block assigned to Canada (CA) by ICAO Annex 10, Volume III. Every aircraft registered in Canada 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
CFMTF - 4 2026-04-14

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-04-14 CFMTF - Apr 14, 05:15 UTCApr 14, 06:00 UTC45m
2026-04-13 CFMTF - Apr 13, 21:05 UTCApr 13, 21:45 UTC40m
2026-04-13 CFMTF - Apr 13, 19:50 UTCApr 13, 20:05 UTC15m
2026-04-13 CFMTF - Apr 13, 18:50 UTCApr 13, 20:05 UTC1h 15m

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 C-FMTF page for operator, model, and routing details .

Mode-S C021A4 frequently asked

What is Mode-S code C021A4?
C021A4 is an ICAO 24-bit transponder address. Allocated to Canada. Assigned to C-FMTF.
Where is Mode-S C021A4 registered?
Mode-S code C021A4 is allocated to Canada (CA). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is C021A4 broadcasting right now?
No active broadcast right now. Last signal was 22h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex C021A4, octal 60020644, decimal 12,591,524.
What flights does C021A4 operate?
Mode-S C021A4 has broadcast 1 distinct callsign, including CFMTF.