sensors Mode-S transponder

A1EFF8

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N224BB · CESSNA 525A Citation CJ2 · operated by SKEELER WILLIAM T

Hex
A1EFF8
Octal
50367770
Decimal
10,612,728
Country
US
Tail
N224BB
Type
C25A
No current signal · last broadcast 2d ago
Flights observed
42
Distinct callsigns
1
Country
US
Last broadcast
2d ago

Last known position

Most recent position reported by Mode-S A1EFF8.

Country allocation

The ICAO 24-bit address A1EFF8 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
N224BB - 42 2026-05-31

Recent flights last 42

DateFlightRouteTakeoffLandingDuration
2026-05-31 N224BB - May 31, 23:15 UTCJun 1, 00:00 UTC45m
2026-05-31 N224BB - May 31, 18:15 UTCMay 31, 19:05 UTC50m
2026-05-31 N224BB - May 31, 17:10 UTCMay 31, 17:35 UTC25m
2026-05-30 N224BB - May 30, 23:15 UTCMay 31, 01:11 UTC1h 56m
2026-05-30 N224BB - May 30, 02:20 UTCMay 30, 03:20 UTC1h 0m
2026-05-29 N224BB - May 29, 23:25 UTCMay 30, 01:30 UTC2h 5m
2026-05-29 N224BB - May 29, 22:20 UTCMay 29, 22:45 UTC25m
2026-05-29 N224BB - May 29, 20:40 UTCMay 29, 21:50 UTC1h 10m
2026-05-29 N224BB - May 29, 17:15 UTCMay 29, 18:30 UTC1h 15m
2026-05-27 N224BB - May 27, 22:30 UTCMay 28, 01:40 UTC3h 10m
2026-05-24 N224BB - May 24, 23:05 UTCMay 24, 23:46 UTC41m
2026-05-22 N224BB - May 22, 23:35 UTCMay 23, 00:05 UTC30m
2026-05-22 N224BB - May 22, 22:35 UTCMay 22, 23:05 UTC30m
2026-05-22 N224BB - May 22, 21:05 UTCMay 22, 21:50 UTC45m
2026-05-10 N224BB - May 10, 22:05 UTCMay 10, 23:09 UTC1h 5m
2026-05-10 N224BB - May 10, 20:35 UTCMay 10, 21:00 UTC25m
2026-05-10 N224BB - May 10, 03:30 UTCMay 10, 03:45 UTC15m
2026-05-10 N224BB - May 10, 00:20 UTCMay 10, 00:55 UTC35m
2026-05-09 N224BB - May 9, 21:14 UTCMay 9, 22:00 UTC45m
2026-05-08 N224BB - May 8, 03:30 UTCMay 8, 03:49 UTC20m
2026-05-08 N224BB - May 8, 00:49 UTCMay 8, 02:55 UTC2h 5m
2026-05-03 N224BB - May 3, 13:30 UTCMay 3, 16:20 UTC2h 50m
2026-05-02 N224BB - May 2, 21:30 UTCMay 2, 21:50 UTC20m
2026-05-02 N224BB - May 2, 20:15 UTCMay 2, 20:45 UTC30m
2026-05-02 N224BB - May 2, 16:15 UTCMay 2, 16:50 UTC35m
2026-04-28 N224BB - Apr 28, 00:55 UTCApr 28, 01:15 UTC20m
2026-04-26 N224BB - Apr 26, 19:55 UTCApr 27, 00:30 UTC4h 35m
2026-04-25 N224BB - Apr 25, 22:55 UTCApr 26, 00:55 UTC2h 0m
2026-04-25 N224BB - Apr 25, 20:50 UTCApr 25, 21:20 UTC30m
2026-04-25 N224BB - Apr 25, 17:55 UTCApr 25, 19:45 UTC1h 50m
2026-04-24 N224BB - Apr 24, 22:40 UTCApr 25, 01:35 UTC2h 55m
2026-04-24 N224BB - Apr 24, 00:45 UTCApr 24, 03:20 UTC2h 35m
2026-04-17 N224BB - Apr 17, 23:25 UTCApr 18, 01:10 UTC1h 45m
2026-04-17 N224BB - Apr 17, 22:30 UTCApr 17, 23:20 UTC50m
2026-04-17 N224BB - Apr 17, 19:25 UTCApr 17, 20:35 UTC1h 10m
2026-04-17 N224BB - Apr 17, 18:25 UTCApr 17, 19:20 UTC55m
2026-04-17 N224BB - Apr 17, 00:35 UTCApr 17, 01:15 UTC40m
2026-04-16 N224BB - Apr 16, 23:20 UTCApr 16, 23:30 UTC10m
2026-04-16 N224BB - Apr 16, 21:45 UTCApr 16, 22:05 UTC20m
2026-04-16 N224BB - Apr 16, 19:15 UTCApr 16, 21:05 UTC1h 50m
2026-04-16 N224BB - Apr 16, 18:15 UTCApr 16, 19:10 UTC55m
2026-04-14 N224BB - Apr 14, 23:50 UTCApr 15, 00:50 UTC1h 0m

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 N224BB page for operator, model, and routing details .

Mode-S A1EFF8 frequently asked

What is Mode-S code A1EFF8?
A1EFF8 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N224BB.
Where is Mode-S A1EFF8 registered?
Mode-S code A1EFF8 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 A1EFF8 broadcasting right now?
No active broadcast right now. Last signal was 2d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1EFF8, octal 50367770, decimal 10,612,728.
What flights does A1EFF8 operate?
Mode-S A1EFF8 has broadcast 1 distinct callsign, including N224BB.