Apparatus

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sensors Mode-S transponder

A851ED

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N635SP · CESSNA 172 Skyhawk · operated by ATP AIRCRAFT 2 LLC

Hex
A851ED
Octal
52050755
Decimal
11,031,021
Country
US
Tail
N635SP
Type
C172
No current signal · last broadcast 1d ago
Flights observed
199
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A851ED.

Country allocation

The ICAO 24-bit address A851ED falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States 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
CXK635 - 199 2026-07-16

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-16 CXK635 - Jul 16, 21:00 UTCJul 16, 22:05 UTC1h 5m
2026-07-09 CXK635 - Jul 9, 20:25 UTCJul 9, 20:45 UTC20m
2026-07-09 CXK635 - Jul 9, 18:05 UTCJul 9, 19:20 UTC1h 15m
2026-07-09 CXK635 - Jul 9, 15:30 UTCJul 9, 16:30 UTC1h 0m
2026-07-09 CXK635 - Jul 9, 04:35 UTCJul 9, 05:50 UTC1h 15m
2026-07-09 CXK635 - Jul 9, 01:00 UTCJul 9, 02:25 UTC1h 25m
2026-07-08 CXK635 - Jul 8, 23:15 UTCJul 9, 00:10 UTC55m
2026-07-08 CXK635 RAL → RAL Jul 8, 19:00 UTCJul 8, 21:10 UTC2h 10m
2026-07-07 CXK635 RAL → RAL Jul 7, 06:50 UTCJul 7, 07:05 UTC15m
2026-07-07 CXK635 RAL → RAL Jul 7, 06:35 UTCJul 7, 06:45 UTC10m
2026-07-07 CXK635 - Jul 7, 04:45 UTCJul 7, 06:20 UTC1h 35m
2026-06-30 CXK635 - Jun 30, 16:45 UTCJun 30, 17:40 UTC55m
2026-06-30 CXK635 - Jun 30, 14:10 UTCJun 30, 15:00 UTC50m
2026-06-28 CXK635 CLD → RAL Jun 28, 01:10 UTCJun 28, 02:25 UTC1h 15m
2026-06-27 CXK635 RAL → CLD Jun 27, 20:34 UTCJun 27, 21:40 UTC1h 5m
2026-06-27 CXK635 RAL → RAL Jun 27, 18:29 UTCJun 27, 19:05 UTC35m
2026-06-27 CXK635 - Jun 27, 03:44 UTCJun 27, 06:15 UTC2h 30m
2026-06-26 CXK635 - Jun 26, 23:04 UTCJun 26, 23:34 UTC30m
2026-06-26 CXK635 - Jun 26, 21:15 UTCJun 26, 21:39 UTC25m
2026-06-26 CXK635 - Jun 26, 04:20 UTCJun 26, 04:59 UTC40m
2026-06-25 CXK635 - Jun 25, 22:54 UTCJun 26, 00:45 UTC1h 50m
2026-06-25 CXK635 - Jun 25, 19:59 UTCJun 25, 21:05 UTC1h 5m
2026-06-25 CXK635 - Jun 25, 17:30 UTCJun 25, 19:09 UTC1h 40m
2026-06-25 CXK635 - Jun 25, 04:25 UTCJun 25, 05:05 UTC40m
2026-06-24 CXK635 LGB → LGB Jun 24, 23:14 UTCJun 25, 00:09 UTC55m
2026-06-24 CXK635 - Jun 24, 20:35 UTCJun 24, 21:50 UTC1h 15m
2026-06-24 CXK635 LGB → LGB Jun 24, 16:59 UTCJun 24, 18:09 UTC1h 10m
2026-06-24 CXK635 - Jun 24, 04:05 UTCJun 24, 04:59 UTC55m
2026-06-24 CXK635 - Jun 24, 01:34 UTCJun 24, 02:49 UTC1h 15m
2026-06-23 CXK635 - Jun 23, 21:54 UTCJun 23, 22:55 UTC1h 0m
2026-06-23 CXK635 - Jun 23, 20:04 UTCJun 23, 20:29 UTC25m
2026-06-22 CXK635 - Jun 22, 19:44 UTCJun 22, 21:30 UTC1h 45m
2026-06-22 CXK635 - Jun 22, 17:15 UTCJun 22, 18:49 UTC1h 35m
2026-06-22 CXK635 LGB → LGB Jun 22, 15:10 UTCJun 22, 15:54 UTC45m
2026-06-22 CXK635 LGB → LGB Jun 22, 01:35 UTCJun 22, 02:59 UTC1h 25m
2026-06-21 CXK635 - Jun 21, 18:54 UTCJun 21, 20:29 UTC1h 35m
2026-06-20 CXK635 - Jun 20, 23:10 UTCJun 21, 00:14 UTC1h 5m
2026-06-20 CXK635 - Jun 20, 17:59 UTCJun 20, 19:15 UTC1h 15m
2026-06-20 CXK635 - Jun 20, 16:55 UTCJun 20, 17:54 UTC1h 0m
2026-06-19 CXK635 - Jun 19, 23:04 UTCJun 20, 00:04 UTC1h 0m
2026-06-19 CXK635 - Jun 19, 16:55 UTCJun 19, 18:44 UTC1h 50m
2026-06-18 CXK635 - Jun 18, 23:40 UTCJun 19, 00:05 UTC25m
2026-06-18 CXK635 - Jun 18, 20:30 UTCJun 18, 22:05 UTC1h 35m
2026-06-18 CXK635 - Jun 18, 17:00 UTCJun 18, 18:30 UTC1h 30m
2026-06-17 CXK635 - Jun 17, 23:05 UTCJun 17, 23:50 UTC45m
2026-06-17 CXK635 - Jun 17, 19:55 UTCJun 17, 22:05 UTC2h 10m
2026-06-17 CXK635 - Jun 17, 01:25 UTCJun 17, 02:05 UTC40m
2026-06-16 CXK635 - Jun 16, 01:35 UTCJun 16, 02:45 UTC1h 10m
2026-06-15 CXK635 - Jun 15, 21:04 UTCJun 15, 21:55 UTC50m
2026-06-15 CXK635 - Jun 15, 16:19 UTCJun 15, 17:15 UTC55m

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 N635SP page for operator, model, and routing details .

Mode-S A851ED frequently asked

What is Mode-S code A851ED?
A851ED is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N635SP.
Where is Mode-S A851ED registered?
Mode-S code A851ED is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is A851ED 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 A851ED, octal 52050755, decimal 11,031,021.
What flights does A851ED operate?
Mode-S A851ED has broadcast 1 distinct callsign, including CXK635.