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sensors Mode-S transponder

C81C33

ICAO 24-bit transponder address · allocated to New Zealand

Currently assigned to ZK-NPK · CESSNA 152

Hex
C81C33
Octal
62016063
Decimal
13,114,419
Country
NZ
Tail
ZK-NPK
Type
C152
No current signal · last broadcast 1h ago
Flights observed
120
Distinct callsigns
1
Country
NZ
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S C81C33.

Country allocation

The ICAO 24-bit address C81C33 falls within the block assigned to New Zealand (NZ) by ICAO Annex 10, Volume III. Every aircraft registered in New Zealand 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
ZKNPK - 120 2026-05-30

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 ZKNPK - May 30, 01:55 UTCMay 30, 02:40 UTC45m
2026-05-30 ZKNPK - May 30, 01:05 UTCMay 30, 01:15 UTC10m
2026-05-29 ZKNPK - May 29, 22:45 UTCMay 30, 00:30 UTC1h 45m
2026-05-29 ZKNPK - May 29, 20:20 UTCMay 29, 21:30 UTC1h 10m
2026-05-29 ZKNPK - May 29, 03:25 UTCMay 29, 03:45 UTC20m
2026-05-29 ZKNPK - May 29, 01:50 UTCMay 29, 02:05 UTC15m
2026-05-28 ZKNPK NPE → NPE May 28, 23:25 UTCMay 29, 00:40 UTC1h 15m
2026-05-28 ZKNPK - May 28, 20:40 UTCMay 28, 21:20 UTC40m
2026-05-28 ZKNPK - May 28, 07:30 UTCMay 28, 08:10 UTC40m
2026-05-28 ZKNPK - May 28, 06:05 UTCMay 28, 06:45 UTC40m
2026-05-28 ZKNPK - May 28, 04:00 UTCMay 28, 04:30 UTC30m
2026-05-28 ZKNPK - May 28, 02:15 UTCMay 28, 02:30 UTC15m
2026-05-28 ZKNPK - May 28, 00:00 UTCMay 28, 00:40 UTC40m
2026-05-27 ZKNPK - May 27, 22:30 UTCMay 27, 23:15 UTC45m
2026-05-27 ZKNPK - May 27, 20:45 UTCMay 27, 21:35 UTC50m
2026-05-27 ZKNPK - May 27, 03:34 UTCMay 27, 04:04 UTC30m
2026-05-26 ZKNPK NPE → NPE May 26, 22:15 UTCMay 26, 23:05 UTC50m
2026-05-26 ZKNPK - May 26, 20:29 UTCMay 26, 21:09 UTC40m
2026-05-26 ZKNPK - May 26, 00:39 UTCMay 26, 01:44 UTC1h 5m
2026-05-25 ZKNPK - May 25, 23:00 UTCMay 25, 23:40 UTC40m
2026-05-25 ZKNPK NPE → NPE May 25, 21:30 UTCMay 25, 22:10 UTC40m
2026-05-25 ZKNPK NPE → NPE May 25, 07:35 UTCMay 25, 08:15 UTC40m
2026-05-25 ZKNPK - May 25, 06:05 UTCMay 25, 06:45 UTC40m
2026-05-25 ZKNPK - May 25, 02:50 UTCMay 25, 04:30 UTC1h 40m
2026-05-25 ZKNPK NPE → NPE May 25, 01:55 UTCMay 25, 02:10 UTC15m
2026-05-24 ZKNPK - May 24, 21:10 UTCMay 24, 21:35 UTC25m
2026-05-23 ZKNPK - May 23, 01:45 UTCMay 23, 02:05 UTC20m
2026-05-23 ZKNPK - May 23, 00:30 UTCMay 23, 00:55 UTC25m
2026-05-22 ZKNPK - May 22, 23:05 UTCMay 22, 23:20 UTC15m
2026-05-22 ZKNPK - May 22, 21:40 UTCMay 22, 22:20 UTC40m
2026-05-22 ZKNPK NPE → NPE May 22, 03:55 UTCMay 22, 04:35 UTC40m
2026-05-22 ZKNPK - May 22, 02:10 UTCMay 22, 02:40 UTC30m
2026-05-22 ZKNPK NPE → NPE May 22, 00:30 UTCMay 22, 01:25 UTC55m
2026-05-21 ZKNPK - May 21, 22:35 UTCMay 21, 23:35 UTC1h 0m
2026-05-21 ZKNPK NPE → NPE May 21, 20:30 UTCMay 21, 21:05 UTC35m
2026-05-21 ZKNPK - May 21, 05:35 UTCMay 21, 06:10 UTC35m
2026-05-21 ZKNPK - May 21, 03:50 UTCMay 21, 04:20 UTC30m
2026-05-21 ZKNPK - May 21, 02:45 UTCMay 21, 03:10 UTC25m
2026-05-20 ZKNPK - May 20, 23:55 UTCMay 21, 01:35 UTC1h 40m
2026-05-20 ZKNPK - May 20, 20:40 UTCMay 20, 21:20 UTC40m
2026-05-20 ZKNPK - May 20, 03:25 UTCMay 20, 04:15 UTC50m
2026-05-20 ZKNPK NPE → NPE May 20, 02:05 UTCMay 20, 02:40 UTC35m
2026-05-20 ZKNPK - May 20, 00:05 UTCMay 20, 01:30 UTC1h 25m
2026-05-19 ZKNPK NPE → NPE May 19, 22:00 UTCMay 19, 23:05 UTC1h 5m
2026-05-19 ZKNPK - May 19, 20:25 UTCMay 19, 21:15 UTC50m
2026-05-19 ZKNPK NPE → NPE May 19, 04:25 UTCMay 19, 04:55 UTC30m
2026-05-19 ZKNPK NPE → NPE May 19, 01:55 UTCMay 19, 03:40 UTC1h 45m
2026-05-15 ZKNPK - May 15, 02:30 UTCMay 15, 04:45 UTC2h 15m
2026-05-14 ZKNPK - May 14, 22:20 UTCMay 14, 23:20 UTC1h 0m
2026-05-14 ZKNPK - May 14, 20:15 UTCMay 14, 21:25 UTC1h 10m

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 ZK-NPK page for operator, model, and routing details .

Mode-S C81C33 frequently asked

What is Mode-S code C81C33?
C81C33 is an ICAO 24-bit transponder address. Allocated to New Zealand. Assigned to ZK-NPK.
Where is Mode-S C81C33 registered?
Mode-S code C81C33 is allocated to New Zealand (NZ). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is C81C33 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex C81C33, octal 62016063, decimal 13,114,419.
What flights does C81C33 operate?
Mode-S C81C33 has broadcast 1 distinct callsign, including ZKNPK.