Apparatus

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sensors Mode-S transponder

A54FF9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N441SW · BOMBARDIER Regional Jet CRJ-200 · operated by SKYWEST AIRLINES INC

Hex
A54FF9
Octal
51247771
Decimal
10,833,913
Country
US
Tail
N441SW
Type
CRJ2
No current signal · last broadcast 1d ago
Flights observed
68
Distinct callsigns
20
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A54FF9.

Country allocation

The ICAO 24-bit address A54FF9 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 20 distinct

Callsign Airline Flights Last seen
SCW4619 Malmö Aviation 3 2026-05-30
SCW4611 Malmö Aviation 3 2026-05-25
SCW3613 Malmö Aviation 3 2026-05-25
SCW3510 Malmö Aviation 3 2026-04-25
SCW4620 Malmö Aviation 2 2026-05-30
SCW4618 Malmö Aviation 2 2026-05-29
SCW4617 Malmö Aviation 2 2026-05-29
SCW4616 Malmö Aviation 2 2026-05-29
SCW4615 Malmö Aviation 2 2026-05-29
SCW4606 Malmö Aviation 2 2026-05-31
SCW4605 Malmö Aviation 2 2026-05-31
SCW4604 Malmö Aviation 2 2026-05-31
SCW4602 Malmö Aviation 2 2026-05-31
SCW3617 Malmö Aviation 2 2026-05-29
SCW3612 Malmö Aviation 2 2026-05-28
SCW3611 Malmö Aviation 2 2026-05-22
SCW4900 Malmö Aviation 1 2026-05-10
SCW4837 Malmö Aviation 1 2026-04-16
SCW4813 Malmö Aviation 1 2026-05-17
SCW4810 Malmö Aviation 1 2026-05-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-06-01 SCW3610 ACY → ISO Jun 1, 19:40 UTCJun 1, 23:15 UTC3h 35m
2026-06-01 SCW4607 ACY → FRG Jun 1, 17:55 UTCJun 1, 18:35 UTC40m
2026-06-01 SCW3602 ACY → SOP Jun 1, 00:35 UTCJun 1, 01:30 UTC55m
2026-05-31 SCW4606 RDU → ACY May 31, 23:10 UTCJun 1, 00:05 UTC55m
2026-05-31 SCW3601 SBN → FRG May 31, 21:50 UTCMay 31, 22:25 UTC35m
2026-05-31 SCW4605 ACY → FRG May 31, 20:15 UTCMay 31, 20:50 UTC35m
2026-05-31 SCW3620 DTW → MKE May 31, 18:30 UTCMay 31, 19:20 UTC50m
2026-05-31 SCW4604 FRG → ACY May 31, 16:55 UTCMay 31, 17:40 UTC45m
2026-05-31 SCW4603 RDU → ACY May 31, 15:35 UTCMay 31, 16:00 UTC25m
2026-05-31 SCW4602 SOP → ACY May 31, 14:20 UTCMay 31, 14:50 UTC30m
2026-05-30 SCW4601 CAK → PIA May 30, 16:10 UTCMay 30, 16:35 UTC25m
2026-05-30 SCW4620 FRG → ACY May 30, 14:50 UTCMay 30, 15:25 UTC35m
2026-05-30 SCW4619 ACY → FRG May 30, 12:45 UTCMay 30, 13:45 UTC1h 0m
2026-05-30 SCW3619 FRG → DTW May 30, 10:40 UTCMay 30, 11:35 UTC55m
2026-05-29 SCW4618 FRG → ACY May 29, 22:10 UTCMay 29, 22:45 UTC35m
2026-05-29 SCW3618 ORF → ACY May 29, 20:40 UTCMay 29, 21:20 UTC40m
2026-05-29 SCW4617 ACY → FRG May 29, 19:10 UTCMay 29, 20:05 UTC55m
2026-05-29 SCW3617 FRG → DTW May 29, 16:50 UTCMay 29, 17:45 UTC55m
2026-05-29 SCW4616 FRG → ACY May 29, 15:25 UTCMay 29, 16:00 UTC35m
2026-05-29 SCW4615 ACY → FRG May 29, 14:05 UTCMay 29, 14:35 UTC30m
2026-05-28 SCW4614 ACY → FRG May 28, 15:25 UTCMay 28, 15:50 UTC25m
2026-05-28 SCW3612 ORF → ACY May 28, 12:25 UTCMay 28, 13:35 UTC1h 10m
2026-05-25 SCW3613 ORF → ACY May 25, 19:25 UTCMay 25, 20:55 UTC1h 30m
2026-05-25 SCW4611 FRG → ACY May 25, 18:10 UTCMay 25, 18:50 UTC40m
2026-05-24 SCW4606 RDU → ACY May 24, 23:20 UTCMay 24, 23:46 UTC26m
2026-05-23 SCW4605 ACY → FRG May 23, 16:00 UTCMay 23, 16:30 UTC30m
2026-05-23 SCW4604 FRG → ACY May 23, 14:55 UTCMay 23, 15:25 UTC30m
2026-05-22 SCW4602 SOP → ACY May 22, 20:55 UTCMay 22, 21:45 UTC50m
2026-05-22 SCW3612 ORF → ACY May 22, 18:10 UTCMay 22, 20:20 UTC2h 10m
2026-05-22 SCW3611 ACY → SBN May 22, 16:20 UTCMay 22, 17:05 UTC45m
2026-05-22 SCW4620 FRG → ACY May 22, 15:10 UTCMay 22, 15:40 UTC30m
2026-05-22 SCW4619 ACY → FRG May 22, 13:50 UTCMay 22, 14:25 UTC35m
2026-05-21 SCW4618 FRG → ACY May 21, 15:10 UTCMay 21, 15:40 UTC30m
2026-05-21 SCW4617 ACY → FRG May 21, 13:55 UTCMay 21, 14:25 UTC30m
2026-05-21 SCW3617 FRG → DTW May 21, 10:50 UTCMay 21, 12:00 UTC1h 10m
2026-05-18 SCW3616 FRG → SBN May 18, 22:55 UTCMay 19, 00:20 UTC1h 25m
2026-05-18 SCW4616 FRG → ACY May 18, 19:35 UTCMay 18, 20:05 UTC30m
2026-05-18 SCW4615 ACY → FRG May 18, 18:15 UTCMay 18, 18:50 UTC34m
2026-05-18 SCW3615 FRG → DTW May 18, 15:15 UTCMay 18, 15:50 UTC35m
2026-05-18 SCW4619 ACY → FRG May 18, 03:10 UTCMay 18, 03:50 UTC40m
2026-05-18 SCW3621 USA → ACY May 18, 01:15 UTCMay 18, 02:25 UTC1h 10m
2026-05-17 SCW4521 OKC → CLL May 17, 22:55 UTCMay 18, 00:00 UTC1h 5m
2026-05-17 SCW3511 USA → BNA May 17, 03:10 UTCMay 17, 04:25 UTC1h 15m
2026-05-17 SCW4813 SBN → PIT May 17, 00:40 UTCMay 17, 02:20 UTC1h 40m
2026-05-13 SCW4810 CMH → MIA May 13, 18:00 UTCMay 13, 19:55 UTC1h 55m
2026-05-13 SCW3800 SBN → RDU May 13, 15:55 UTCMay 13, 16:25 UTC30m
2026-05-11 SCW3900 BED → BNA May 11, 01:10 UTCMay 11, 01:55 UTC45m
2026-05-10 SCW4900 AUS → COU May 10, 22:49 UTCMay 11, 00:25 UTC1h 35m
2026-05-08 SCW4509 LEX → OKC May 8, 14:20 UTCMay 8, 16:25 UTC2h 5m
2026-05-06 SCW4506 OKC → LEX May 6, 21:30 UTCMay 6, 22:55 UTC1h 25m

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 N441SW page for operator, model, and routing details .

Mode-S A54FF9 frequently asked

What is Mode-S code A54FF9?
A54FF9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N441SW.
Where is Mode-S A54FF9 registered?
Mode-S code A54FF9 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 A54FF9 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 A54FF9, octal 51247771, decimal 10,833,913.
What flights does A54FF9 operate?
Mode-S A54FF9 has broadcast 20 distinct callsigns, including SCW4619, SCW4611, SCW3613, SCW3510, SCW4620.