Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A5DEE3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N478AS · BOEING 737-900 · operated by ALASKA AIRLINES INC

Hex
A5DEE3
Octal
51357343
Decimal
10,870,499
Country
US
Tail
N478AS
Type
B739
Broadcasting now · callsign ASA1721 · 37,000 ft
Flights observed
481
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:40 UTC

Current position

A5DEE3 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A5DEE3 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
ASA450 Alaska Airlines 7 2026-04-16
ASA725 Alaska Airlines 5 2026-07-20
ASA656 - 5 2026-07-20
ASA639 Alaska Airlines 5 2026-05-25
ASA418 - 5 2026-07-17
ASA405 Alaska Airlines 5 2026-06-16
ASA235 - 5 2026-07-05
ASA222 - 5 2026-06-21
ASA1386 Alaska Airlines 5 2026-06-02
ASA1346 Alaska Airlines 5 2026-04-30
ASA740 Alaska Airlines 4 2026-06-02
ASA649 Alaska Airlines 4 2026-06-03
ASA648 - 4 2026-06-23
ASA626 - 4 2026-06-27
ASA618 Alaska Airlines 4 2026-05-17
ASA404 - 4 2026-06-23
ASA1403 Alaska Airlines 4 2026-04-15
ASA1366 - 4 2026-06-25
ASA1349 - 4 2026-07-21
ASA785 Alaska Airlines 3 2026-05-01

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ASA1639 SAN → TPA Jul 26, 17:00 UTCJul 26, 21:30 UTC4h 30m
2026-07-26 ASA1617 DEN → SAN Jul 26, 12:20 UTCJul 26, 14:15 UTC1h 55m
2026-07-26 ASA1619 SAN → DEN Jul 26, 03:15 UTCJul 26, 05:10 UTC1h 55m
2026-07-26 ASA266 SJC → PDX Jul 26, 01:00 UTCJul 26, 01:50 UTC50m
2026-07-25 ASA266 SJC → PDX Jul 25, 20:55 UTCJul 25, 21:10 UTC15m
2026-07-25 ASA693 PDX → SFO Jul 25, 19:30 UTCJul 25, 19:35 UTC5m
2026-07-25 ASA693 PDX → SFO Jul 25, 14:35 UTCJul 25, 15:15 UTC40m
2026-07-25 ASA59 SEA → ANC Jul 25, 01:00 UTCJul 25, 06:35 UTC5h 35m
2026-07-24 ASA34 SEA → JFK Jul 24, 17:35 UTCJul 24, 22:05 UTC4h 30m
2026-07-24 ASA274 SEA → EWR Jul 24, 11:15 UTCJul 24, 15:50 UTC4h 35m
2026-07-24 ASA269 SFO → ANC Jul 24, 05:40 UTCJul 24, 09:15 UTC3h 35m
2026-07-23 ASA787 LAS → SEA Jul 23, 22:30 UTCJul 24, 03:55 UTC5h 25m
2026-07-23 ASA787 LAS → SEA Jul 23, 16:10 UTCJul 23, 20:40 UTC4h 30m
2026-07-23 ASA403 LAS → SEA Jul 23, 03:45 UTCJul 23, 05:10 UTC1h 25m
2026-07-23 ASA1622 PDX → SMF Jul 23, 01:15 UTCJul 23, 02:30 UTC1h 15m
2026-07-22 ASA1302 SEA → LAX Jul 22, 22:25 UTCJul 22, 23:35 UTC1h 10m
2026-07-22 ASA655 ABQ → SEA Jul 22, 19:10 UTCJul 22, 21:05 UTC1h 55m
2026-07-22 ASA786 - Jul 22, 11:20 UTCJul 22, 16:40 UTC5h 20m
2026-07-22 ASA786 BWI → SEA Jul 22, 11:13 UTCJul 22, 16:33 UTC5h 20m
2026-07-22 ASA781 SNA → SEA Jul 22, 05:05 UTCJul 22, 05:25 UTC20m
2026-07-22 ASA665 PDX → ANC Jul 22, 01:11 UTCJul 22, 02:38 UTC1h 27m
2026-07-22 ASA665 PDX → ANC Jul 22, 01:15 UTCJul 22, 02:45 UTC1h 30m
2026-07-21 ASA368 SFO → MCO Jul 21, 21:55 UTCJul 21, 23:45 UTC1h 50m
2026-07-21 ASA637 PHX → SEA Jul 21, 18:13 UTCJul 21, 20:19 UTC2h 6m
2026-07-21 ASA637 - Jul 21, 18:05 UTCJul 21, 20:25 UTC2h 20m
2026-07-21 ASA1349 PDX → PHX Jul 21, 14:30 UTCJul 21, 16:45 UTC2h 15m
2026-07-21 ASA1457 SEA → PDX Jul 21, 06:25 UTCJul 21, 06:55 UTC30m
2026-07-21 ASA532 LAX → PDX Jul 21, 01:20 UTCJul 21, 04:50 UTC3h 30m
2026-07-20 ASA527 SNA → SEA Jul 20, 20:55 UTCJul 20, 23:30 UTC2h 35m
2026-07-20 ASA656 - Jul 20, 17:55 UTCJul 20, 19:20 UTC1h 25m
2026-07-20 ASA725 LAS → PDX Jul 20, 14:45 UTCJul 20, 16:35 UTC1h 50m
2026-07-20 ASA206 PDX → SFO Jul 20, 11:55 UTCJul 20, 12:40 UTC45m
2026-07-20 ASA206 PDX → SFO Jul 20, 07:57 UTCJul 20, 12:31 UTC4h 34m
2026-07-20 ASA353 PDX → OGG Jul 20, 01:00 UTCJul 20, 06:16 UTC5h 16m
2026-07-19 ASA1402 - Jul 19, 21:30 UTCJul 19, 23:25 UTC1h 55m
2026-07-19 ASA1618 SAN → DEN Jul 19, 17:55 UTCJul 19, 19:40 UTC1h 45m
2026-07-19 ASA1618 SAN → DEN Jul 19, 14:35 UTCJul 19, 16:35 UTC2h 0m
2026-07-19 ASA336 PDX → FLL Jul 19, 03:40 UTCJul 19, 06:05 UTC2h 25m
2026-07-18 ASA1506 BOS → SEA Jul 18, 20:00 UTCJul 19, 01:50 UTC5h 50m
2026-07-18 ASA1505 SEA → BNH Jul 18, 13:20 UTCJul 18, 18:10 UTC4h 50m
2026-07-18 ASA282 - Jul 18, 04:10 UTCJul 18, 05:45 UTC1h 35m
2026-07-18 ASA393 SEA → FAT Jul 18, 00:53 UTCJul 18, 02:41 UTC1h 48m
2026-07-18 ASA393 - Jul 18, 00:50 UTCJul 18, 02:40 UTC1h 50m
2026-07-17 ASA418 - Jul 17, 19:30 UTCJul 17, 22:45 UTC3h 15m
2026-07-17 ASA418 - Jul 17, 15:05 UTCJul 17, 18:10 UTC3h 5m
2026-07-17 ASA75 ANC → SEA Jul 17, 10:44 UTCJul 17, 13:50 UTC3h 5m
2026-07-17 ASA1532 PHX → ANC Jul 17, 02:05 UTCJul 17, 07:14 UTC5h 10m
2026-07-17 ASA1532 PHX → ANC Jul 17, 02:04 UTCJul 17, 07:04 UTC5h 0m
2026-07-16 ASA731 - Jul 16, 22:05 UTCJul 17, 00:50 UTC2h 45m
2026-07-16 ASA684 DEN → PDX Jul 16, 18:15 UTCJul 16, 20:19 UTC2h 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 N478AS page for operator, model, and routing details .

Mode-S A5DEE3 frequently asked

What is Mode-S code A5DEE3?
A5DEE3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N478AS.
Where is Mode-S A5DEE3 registered?
Mode-S code A5DEE3 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 A5DEE3 broadcasting right now?
Yes. Mode-S A5DEE3 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A5DEE3, octal 51357343, decimal 10,870,499.
What flights does A5DEE3 operate?
Mode-S A5DEE3 has broadcast 20 distinct callsigns, including ASA450, ASA725, ASA656, ASA639, ASA418.