Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A4FFCA

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N421ER · CESSNA 172 Skyhawk · operated by CC AVIATION INC

Hex
A4FFCA
Octal
51177712
Decimal
10,813,386
Country
US
Tail
N421ER
Type
C172
No current signal · last broadcast 1d ago
Flights observed
293
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A4FFCA.

Country allocation

The ICAO 24-bit address A4FFCA 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
N421ER - 293 2026-07-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-21 N421ER - Jul 21, 17:40 UTCJul 21, 18:05 UTC25m
2026-07-20 N421ER - Jul 20, 23:40 UTCJul 21, 00:40 UTC1h 0m
2026-07-18 N421ER - Jul 18, 19:10 UTCJul 18, 19:50 UTC40m
2026-07-18 N421ER - Jul 18, 17:15 UTCJul 18, 18:00 UTC45m
2026-07-18 N421ER - Jul 18, 13:40 UTCJul 18, 14:30 UTC50m
2026-07-18 N421ER - Jul 18, 02:09 UTCJul 18, 02:40 UTC30m
2026-07-17 N421ER - Jul 17, 23:30 UTCJul 18, 00:55 UTC1h 25m
2026-07-17 N421ER - Jul 17, 21:20 UTCJul 17, 22:20 UTC1h 0m
2026-07-17 N421ER - Jul 17, 18:00 UTCJul 17, 19:45 UTC1h 45m
2026-07-17 N421ER - Jul 17, 15:49 UTCJul 17, 16:49 UTC1h 0m
2026-07-17 N421ER - Jul 17, 03:25 UTCJul 17, 04:54 UTC1h 30m
2026-07-17 N421ER - Jul 17, 00:50 UTCJul 17, 01:49 UTC1h 0m
2026-07-16 N421ER - Jul 16, 20:55 UTCJul 16, 21:35 UTC40m
2026-07-16 N421ER - Jul 16, 18:40 UTCJul 16, 19:40 UTC1h 0m
2026-07-16 N421ER - Jul 16, 00:05 UTCJul 16, 01:00 UTC55m
2026-07-15 N421ER - Jul 15, 22:00 UTCJul 15, 23:05 UTC1h 5m
2026-07-15 N421ER - Jul 15, 19:55 UTCJul 15, 21:10 UTC1h 15m
2026-07-15 N421ER - Jul 15, 18:40 UTCJul 15, 18:55 UTC15m
2026-07-15 N421ER - Jul 15, 17:25 UTCJul 15, 18:10 UTC45m
2026-07-15 N421ER - Jul 15, 15:25 UTCJul 15, 16:20 UTC55m
2026-07-15 N421ER - Jul 15, 00:00 UTCJul 15, 01:15 UTC1h 15m
2026-07-14 N421ER - Jul 14, 21:00 UTCJul 14, 22:05 UTC1h 5m
2026-07-14 N421ER - Jul 14, 19:00 UTCJul 14, 20:05 UTC1h 5m
2026-07-14 N421ER - Jul 14, 17:05 UTCJul 14, 18:05 UTC1h 0m
2026-07-14 N421ER - Jul 14, 06:15 UTCJul 14, 06:55 UTC40m
2026-07-14 N421ER - Jul 14, 05:40 UTCJul 14, 05:50 UTC10m
2026-07-14 N421ER - Jul 14, 01:20 UTCJul 14, 02:25 UTC1h 5m
2026-07-13 N421ER - Jul 13, 23:15 UTCJul 14, 00:25 UTC1h 10m
2026-07-13 N421ER - Jul 13, 20:05 UTCJul 13, 22:30 UTC2h 25m
2026-07-13 N421ER - Jul 13, 16:25 UTCJul 13, 17:10 UTC45m
2026-07-12 N421ER - Jul 12, 18:45 UTCJul 12, 19:15 UTC30m
2026-07-12 N421ER - Jul 12, 17:15 UTCJul 12, 17:50 UTC35m
2026-07-12 N421ER - Jul 12, 16:40 UTCJul 12, 17:10 UTC30m
2026-07-12 N421ER - Jul 12, 04:05 UTCJul 12, 04:15 UTC10m
2026-07-12 N421ER - Jul 12, 00:10 UTCJul 12, 01:15 UTC1h 5m
2026-07-11 N421ER - Jul 11, 17:35 UTCJul 11, 18:25 UTC50m
2026-07-11 N421ER - Jul 11, 17:15 UTCJul 11, 17:20 UTC5m
2026-07-11 N421ER - Jul 11, 16:55 UTCJul 11, 17:05 UTC10m
2026-07-11 N421ER - Jul 11, 16:40 UTCJul 11, 16:45 UTC5m
2026-07-11 N421ER - Jul 11, 03:10 UTCJul 11, 04:01 UTC50m
2026-07-10 N421ER - Jul 10, 16:50 UTCJul 10, 16:55 UTC5m
2026-07-10 N421ER - Jul 10, 16:35 UTCJul 10, 16:45 UTC10m
2026-07-10 N421ER - Jul 10, 16:00 UTCJul 10, 16:10 UTC10m
2026-07-10 N421ER - Jul 10, 03:45 UTCJul 10, 05:05 UTC1h 20m
2026-07-09 N421ER - Jul 9, 23:20 UTCJul 10, 00:40 UTC1h 20m
2026-07-09 N421ER - Jul 9, 17:40 UTCJul 9, 19:15 UTC1h 35m
2026-07-09 N421ER - Jul 9, 03:00 UTCJul 9, 03:15 UTC15m
2026-07-09 N421ER - Jul 9, 00:10 UTCJul 9, 00:30 UTC20m
2026-07-08 N421ER - Jul 8, 22:25 UTCJul 8, 23:55 UTC1h 30m
2026-07-08 N421ER - Jul 8, 19:45 UTCJul 8, 20:25 UTC40m

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 N421ER page for operator, model, and routing details .

Mode-S A4FFCA frequently asked

What is Mode-S code A4FFCA?
A4FFCA is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N421ER.
Where is Mode-S A4FFCA registered?
Mode-S code A4FFCA 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 A4FFCA 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 A4FFCA, octal 51177712, decimal 10,813,386.
What flights does A4FFCA operate?
Mode-S A4FFCA has broadcast 1 distinct callsign, including N421ER.