sensors Mode-S transponder

A63F4E

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N501SY · EMBRAER ERJ-170-200 (long wing) · operated by SKYWEST AIRLINES INC

Hex
A63F4E
Octal
51437516
Decimal
10,895,182
Country
US
Tail
N501SY
Type
E75L
No current signal · last broadcast 1d ago
Flights observed
14
Distinct callsigns
5
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A63F4E.

Country allocation

The ICAO 24-bit address A63F4E 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 5 distinct

Callsign Airline Flights Last seen
SKW4925 SkyWest Airlines 4 2026-04-13
SKW6460 - 3 2026-04-13
SKW4924 - 3 2026-04-13
SKW4914 - 3 2026-04-13
SKW4980 - 1 2026-04-12

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-04-13 SKW4925 PHX → HMO Apr 13, 21:45 UTCApr 13, 23:05 UTC1h 20m
2026-04-13 SKW4925 PHX → HMO Apr 13, 19:50 UTCApr 13, 20:50 UTC1h 0m
2026-04-13 SKW4925 PHX → HMO Apr 13, 19:35 UTCApr 13, 20:10 UTC35m
2026-04-13 SKW4925 PHX → HMO Apr 13, 17:44 UTCApr 13, 19:17 UTC1h 33m
2026-04-13 SKW4914 - Apr 13, 16:15 UTCApr 13, 17:25 UTC1h 10m
2026-04-13 SKW4914 - Apr 13, 15:57 UTCApr 13, 18:33 UTC2h 36m
2026-04-13 SKW4914 - Apr 13, 15:47 UTCApr 13, 18:23 UTC2h 36m
2026-04-13 SKW4924 - Apr 13, 04:20 UTCApr 13, 04:40 UTC20m
2026-04-13 SKW4924 - Apr 13, 03:55 UTCApr 13, 04:40 UTC45m
2026-04-13 SKW4924 - Apr 13, 02:50 UTCApr 13, 04:37 UTC1h 47m
2026-04-13 SKW6460 - Apr 13, 00:20 UTCApr 13, 01:05 UTC45m
2026-04-12 SKW6460 - Apr 12, 23:55 UTCApr 13, 01:05 UTC1h 10m
2026-04-12 SKW6460 - Apr 12, 18:55 UTCApr 12, 20:00 UTC1h 5m
2026-04-12 SKW4980 - Apr 12, 16:45 UTCApr 12, 17:52 UTC1h 7m

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 N501SY page for operator, model, and routing details .

Mode-S A63F4E frequently asked

What is Mode-S code A63F4E?
A63F4E is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N501SY.
Where is Mode-S A63F4E registered?
Mode-S code A63F4E 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 A63F4E 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 A63F4E, octal 51437516, decimal 10,895,182.
What flights does A63F4E operate?
Mode-S A63F4E has broadcast 5 distinct callsigns, including SKW4925, SKW6460, SKW4924, SKW4914, SKW4980.