Apparatus

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sensors Mode-S transponder

A1A18F

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N204HA · AIRBUS A-321neo · operated by HAWAIIAN AIRLINES INC

Hex
A1A18F
Octal
50320617
Decimal
10,592,655
Country
US
Tail
N204HA
Type
A21N
No current signal · last broadcast 2h ago
Flights observed
94
Distinct callsigns
20
Country
US
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S A1A18F.

Country allocation

The ICAO 24-bit address A1A18F 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
ASA888 Alaska Airlines 7 2026-05-05
ASA878 Alaska Airlines 5 2026-05-05
ASA968 Alaska Airlines 4 2026-05-07
ASA964 Alaska Airlines 4 2026-04-26
ASA923 Alaska Airlines 4 2026-05-10
ASA868 Alaska Airlines 4 2026-05-08
ASA978 Alaska Airlines 3 2026-05-11
ASA941 Alaska Airlines 3 2026-05-27
ASA924 Alaska Airlines 3 2026-05-28
ASA848 Alaska Airlines 3 2026-04-29
ASA847 Alaska Airlines 3 2026-05-28
ASA972 Alaska Airlines 2 2026-04-25
ASA971 Alaska Airlines 2 2026-04-24
ASA963 Alaska Airlines 2 2026-05-06
ASA908 Alaska Airlines 2 2026-05-26
ASA904 Alaska Airlines 2 2026-05-29
ASA892 Alaska Airlines 2 2026-04-23
ASA891 Alaska Airlines 2 2026-04-23
ASA869 Alaska Airlines 2 2026-04-25
ASA867 Alaska Airlines 2 2026-05-08

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 ASA903 PVR → SEA May 30, 00:40 UTCMay 30, 01:30 UTC50m
2026-05-29 ASA904 SEA → BZN May 29, 21:50 UTCMay 29, 22:40 UTC50m
2026-05-29 ASA904 SEA → BZN May 29, 17:40 UTCMay 29, 18:00 UTC20m
2026-05-29 ASA843 SFO → LAX May 29, 10:05 UTCMay 29, 10:20 UTC15m
2026-05-29 ASA843 SFO → LAX May 29, 04:40 UTCMay 29, 05:35 UTC55m
2026-05-29 ASA844 LAX → PDX May 29, 01:45 UTCMay 29, 02:40 UTC55m
2026-05-28 ASA844 LAX → PDX May 28, 21:30 UTCMay 28, 21:40 UTC10m
2026-05-28 ASA847 OAK → HNL May 28, 14:20 UTCMay 28, 19:15 UTC4h 55m
2026-05-28 ASA924 RDM → SEA May 28, 03:40 UTCMay 28, 04:15 UTC35m
2026-05-27 ASA941 SEA → ORD May 27, 16:55 UTCMay 27, 17:25 UTC30m
2026-05-27 ASA862 OGG → SEA May 27, 14:25 UTCMay 27, 14:55 UTC30m
2026-05-27 ASA862 OGG → SEA May 27, 10:00 UTCMay 27, 10:20 UTC20m
2026-05-26 ASA907 RDM → SEA May 26, 15:35 UTCMay 26, 20:45 UTC5h 10m
2026-05-26 ASA908 SEA → DFW May 26, 12:30 UTCMay 26, 13:24 UTC55m
2026-05-26 ASA908 SEA → DFW May 26, 07:59 UTCMay 26, 08:19 UTC20m
2026-05-12 ASA9811 ANC → SEA May 12, 19:25 UTCMay 13, 00:35 UTC5h 10m
2026-05-11 ASA978 SEA → FAT May 11, 00:54 UTCMay 11, 01:25 UTC30m
2026-05-10 ASA923 OAK → OGG May 10, 14:14 UTCMay 10, 14:49 UTC35m
2026-05-10 ASA924 RDM → SEA May 10, 01:04 UTCMay 10, 01:45 UTC40m
2026-05-09 ASA941 SEA → ORD May 9, 14:50 UTCMay 9, 15:15 UTC25m
2026-05-09 ASA822 KOA → SEA May 9, 08:00 UTCMay 9, 12:35 UTC4h 35m
2026-05-08 ASA867 PDX → KOA May 8, 13:55 UTCMay 8, 20:05 UTC6h 10m
2026-05-08 ASA868 KOA → PDX May 8, 09:30 UTCMay 8, 11:14 UTC1h 45m
2026-05-08 ASA868 KOA → PDX May 8, 05:20 UTCMay 8, 05:39 UTC20m
2026-05-07 ASA847 OAK → HNL May 7, 22:10 UTCMay 7, 22:25 UTC15m
2026-05-07 ASA847 OAK → HNL May 7, 17:20 UTCMay 7, 17:50 UTC30m
2026-05-07 ASA968 LIH → OAK May 7, 04:05 UTCMay 7, 04:45 UTC40m
2026-05-06 ASA963 GEG → SEA May 6, 16:50 UTCMay 6, 22:05 UTC5h 15m
2026-05-05 ASA878 OGG → SFO May 5, 23:50 UTCMay 6, 04:55 UTC5h 4m
2026-05-05 ASA888 HNL → SEA May 5, 21:20 UTCMay 5, 21:45 UTC25m
2026-05-05 ASA888 HNL → SEA May 5, 16:20 UTCMay 5, 17:15 UTC55m
2026-05-04 ASA878 OGG → SFO May 4, 23:40 UTCMay 5, 04:40 UTC5h 0m
2026-05-04 ASA888 HNL → SEA May 4, 16:35 UTCMay 4, 22:05 UTC5h 31m
2026-05-03 ASA878 OGG → SFO May 3, 23:39 UTCMay 4, 04:39 UTC5h 0m
2026-05-03 ASA888 HNL → SEA May 3, 21:29 UTCMay 3, 21:54 UTC25m
2026-05-03 ASA888 HNL → SEA May 3, 16:34 UTCMay 3, 17:35 UTC1h 0m
2026-05-02 ASA878 OGG → SFO May 2, 23:40 UTCMay 3, 04:35 UTC4h 54m
2026-05-02 ASA821 SJC → OGG May 2, 07:55 UTCMay 2, 08:15 UTC20m
2026-05-02 ASA821 SJC → OGG May 2, 03:20 UTCMay 2, 03:50 UTC30m
2026-05-02 ASA978 SEA → FAT May 2, 01:10 UTCMay 2, 01:40 UTC30m
2026-05-01 ASA923 OAK → OGG May 1, 14:20 UTCMay 1, 15:00 UTC40m
2026-05-01 ASA924 RDM → SEA May 1, 01:55 UTCMay 1, 02:35 UTC40m
2026-04-30 ASA941 SEA → ORD Apr 30, 14:50 UTCApr 30, 15:20 UTC30m
2026-04-30 ASA978 SEA → FAT Apr 30, 01:10 UTCApr 30, 01:45 UTC35m
2026-04-29 ASA923 OAK → OGG Apr 29, 14:30 UTCApr 29, 14:55 UTC25m
2026-04-29 ASA848 HNL → SEA Apr 29, 04:00 UTCApr 29, 04:39 UTC40m
2026-04-28 ASA848 HNL → SEA Apr 28, 23:45 UTCApr 29, 00:00 UTC15m
2026-04-27 ASA888 HNL → SEA Apr 27, 21:05 UTCApr 27, 21:30 UTC25m
2026-04-27 ASA888 HNL → SEA Apr 27, 16:15 UTCApr 27, 17:15 UTC1h 0m
2026-04-26 ASA964 GEG → SEA Apr 26, 22:35 UTCApr 27, 03:40 UTC5h 5m

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 N204HA page for operator, model, and routing details .

Mode-S A1A18F frequently asked

What is Mode-S code A1A18F?
A1A18F is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N204HA.
Where is Mode-S A1A18F registered?
Mode-S code A1A18F 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 A1A18F broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1A18F, octal 50320617, decimal 10,592,655.
What flights does A1A18F operate?
Mode-S A1A18F has broadcast 20 distinct callsigns, including ASA888, ASA878, ASA968, ASA964, ASA923.