Apparatus

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sensors Mode-S transponder

A63E21

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N501EX · CESSNA 208 Caravan · operated by FLOATSIX LEASING LLC

Hex
A63E21
Octal
51437041
Decimal
10,894,881
Country
US
Tail
N501EX
Type
C208
No current signal · last broadcast 6h ago
Flights observed
85
Distinct callsigns
1
Country
US
Last broadcast
6h ago

Last known position

Most recent position reported by Mode-S A63E21.

Country allocation

The ICAO 24-bit address A63E21 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
FTO501 Tropic Ocean Airways 85 2026-05-29

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 FTO501 FLL → BCT May 29, 21:15 UTCMay 29, 21:30 UTC15m
2026-05-29 FTO501 FLL → BCT May 29, 16:10 UTCMay 29, 16:20 UTC10m
2026-05-29 FTO501 FLL → BCT May 29, 13:50 UTCMay 29, 14:00 UTC10m
2026-05-28 FTO501 FLL → BCT May 28, 14:05 UTCMay 28, 14:15 UTC10m
2026-05-28 FTO501 FLL → BCT May 28, 12:55 UTCMay 28, 13:05 UTC10m
2026-05-27 FTO501 FLL → BCT May 27, 22:05 UTCMay 27, 22:20 UTC15m
2026-05-27 FTO501 FLL → BCT May 27, 16:40 UTCMay 27, 16:50 UTC10m
2026-05-27 FTO501 FLL → BCT May 27, 14:00 UTCMay 27, 14:10 UTC10m
2026-05-26 FTO501 FLL → BCT May 26, 18:40 UTCMay 26, 18:50 UTC10m
2026-05-26 FTO501 FLL → BCT May 26, 12:30 UTCMay 26, 13:00 UTC30m
2026-05-25 FTO501 FLL → BCT May 25, 23:30 UTCMay 25, 23:40 UTC10m
2026-05-25 FTO501 FLL → BCT May 25, 19:05 UTCMay 25, 19:15 UTC10m
2026-05-25 FTO501 FLL → BCT May 25, 16:25 UTCMay 25, 16:35 UTC10m
2026-05-25 FTO501 FLL → BCT May 25, 12:00 UTCMay 25, 12:10 UTC10m
2026-05-24 FTO501 FLL → BCT May 24, 21:10 UTCMay 24, 21:20 UTC10m
2026-05-24 FTO501 FLL → BCT May 24, 17:20 UTCMay 24, 17:30 UTC10m
2026-05-24 FTO501 FLL → BCT May 24, 14:30 UTCMay 24, 14:40 UTC10m
2026-05-24 FTO501 FLL → BCT May 24, 11:50 UTCMay 24, 13:00 UTC1h 10m
2026-05-24 FTO501 FLL → BCT May 24, 10:15 UTCMay 24, 10:40 UTC25m
2026-05-23 FTO501 FLL → BCT May 23, 15:15 UTCMay 23, 15:35 UTC20m
2026-05-23 FTO501 FLL → BCT May 23, 14:20 UTCMay 23, 14:30 UTC10m
2026-05-23 FTO501 FLL → BCT May 23, 13:15 UTCMay 23, 13:30 UTC15m
2026-05-22 FTO501 FLL → BCT May 22, 22:05 UTCMay 22, 22:25 UTC20m
2026-05-22 FTO501 FLL → BCT May 22, 19:30 UTCMay 22, 20:30 UTC1h 0m
2026-05-22 FTO501 FLL → BCT May 22, 17:35 UTCMay 22, 18:30 UTC55m
2026-05-22 FTO501 FLL → BCT May 22, 14:05 UTCMay 22, 14:15 UTC10m
2026-05-22 FTO501 FLL → BCT May 22, 13:05 UTCMay 22, 13:15 UTC10m
2026-05-22 FTO501 FLL → BCT May 22, 12:10 UTCMay 22, 12:20 UTC10m
2026-05-21 FTO501 FLL → BCT May 21, 16:45 UTCMay 21, 17:10 UTC25m
2026-05-21 FTO501 FLL → BCT May 21, 15:10 UTCMay 21, 15:40 UTC30m
2026-05-21 FTO501 FLL → BCT May 21, 13:50 UTCMay 21, 14:00 UTC10m
2026-05-20 FTO501 FLL → BCT May 20, 17:55 UTCMay 20, 18:05 UTC10m
2026-05-20 FTO501 FLL → BCT May 20, 15:15 UTCMay 20, 15:40 UTC25m
2026-05-20 FTO501 FLL → BCT May 20, 11:50 UTCMay 20, 12:10 UTC20m
2026-05-19 FTO501 FLL → BCT May 19, 20:40 UTCMay 19, 22:15 UTC1h 35m
2026-05-19 FTO501 FLL → BCT May 19, 17:55 UTCMay 19, 19:25 UTC1h 30m
2026-05-19 FTO501 FLL → BCT May 19, 16:30 UTCMay 19, 16:55 UTC25m
2026-05-19 FTO501 FLL → BCT May 19, 12:10 UTCMay 19, 12:50 UTC40m
2026-05-18 FTO501 FLL → BCT May 18, 20:05 UTCMay 18, 20:45 UTC40m
2026-05-18 FTO501 FLL → BCT May 18, 12:25 UTCMay 18, 13:00 UTC35m
2026-05-17 FTO501 FLL → BCT May 17, 21:45 UTCMay 17, 21:55 UTC10m
2026-05-17 FTO501 FLL → BCT May 17, 20:50 UTCMay 17, 21:01 UTC10m
2026-05-17 FTO501 FLL → BCT May 17, 19:50 UTCMay 17, 20:01 UTC10m
2026-05-17 FTO501 FLL → BCT May 17, 15:45 UTCMay 17, 16:20 UTC35m
2026-05-17 FTO501 FLL → BCT May 17, 14:25 UTCMay 17, 14:35 UTC10m
2026-05-17 FTO501 FLL → BCT May 17, 12:50 UTCMay 17, 13:05 UTC15m
2026-05-11 FTO501 FLL → BCT May 11, 19:40 UTCMay 11, 20:05 UTC25m
2026-05-11 FTO501 FLL → BCT May 11, 12:15 UTCMay 11, 12:55 UTC40m
2026-05-10 FTO501 FLL → BCT May 10, 21:54 UTCMay 10, 22:05 UTC10m
2026-05-10 FTO501 FLL → BCT May 10, 20:54 UTCMay 10, 21:04 UTC10m

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 N501EX page for operator, model, and routing details .

Mode-S A63E21 frequently asked

What is Mode-S code A63E21?
A63E21 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N501EX.
Where is Mode-S A63E21 registered?
Mode-S code A63E21 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 A63E21 broadcasting right now?
No active broadcast right now. Last signal was 6h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A63E21, octal 51437041, decimal 10,894,881.
What flights does A63E21 operate?
Mode-S A63E21 has broadcast 1 distinct callsign, including FTO501.