Apparatus

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sensors Mode-S transponder

A677CA

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N516AS · BOEING 737-800 · operated by WILMINGTON TRUST CO TRUSTEE

Hex
A677CA
Octal
51473712
Decimal
10,909,642
Country
US
Tail
N516AS
Type
B738
Broadcasting now · callsign ASA1574 · 38,000 ft
Flights observed
424
Distinct callsigns
20
Country
US
Last broadcast
1d ago

Current position

A677CA is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A677CA 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
ASA9 - 5 2026-07-07
ASA67 Alaska Airlines 5 2026-05-06
ASA4 Alaska Airlines 5 2026-07-07
ASA1565 Alaska Airlines 5 2026-07-08
ASA697 - 4 2026-06-16
ASA621 - 4 2026-07-08
ASA592 - 4 2026-07-12
ASA555 Alaska Airlines 4 2026-07-24
ASA525 Alaska Airlines 4 2026-05-31
ASA384 Alaska Airlines 4 2026-06-11
ASA291 Alaska Airlines 4 2026-07-21
ASA232 - 4 2026-06-25
ASA89 - 3 2026-06-14
ASA88 - 3 2026-06-15
ASA796 - 3 2026-06-16
ASA780 Alaska Airlines 3 2026-07-21
ASA702 Alaska Airlines 3 2026-06-09
ASA69 Alaska Airlines 3 2026-05-20
ASA60 Alaska Airlines 3 2026-05-26
ASA589 - 3 2026-07-06

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ASA1447 PDX → SJC Jul 26, 19:35 UTCJul 26, 22:30 UTC2h 55m
2026-07-26 ASA1446 CUN → LAX Jul 26, 14:25 UTCJul 26, 18:10 UTC3h 45m
2026-07-26 ASA1348 SEA → PHL Jul 26, 01:25 UTCJul 26, 03:45 UTC2h 20m
2026-07-25 ASA790 SEA → EWR Jul 25, 21:50 UTCJul 25, 23:20 UTC1h 30m
2026-07-25 ASA570 SAN → SEA Jul 25, 17:35 UTCJul 25, 18:50 UTC1h 15m
2026-07-25 ASA718 LAS → SFO Jul 25, 14:45 UTCJul 25, 15:50 UTC1h 5m
2026-07-25 ASA613 SFO → LAS Jul 25, 05:35 UTCJul 25, 06:45 UTC1h 10m
2026-07-25 ASA613 SFO → LAS Jul 25, 05:50 UTCJul 25, 06:39 UTC49m
2026-07-25 ASA478 SEA → LAS Jul 25, 02:15 UTCJul 25, 04:20 UTC2h 5m
2026-07-24 ASA555 MSP → SEA Jul 24, 20:10 UTCJul 24, 23:35 UTC3h 25m
2026-07-24 ASA555 MSP → SEA Jul 24, 16:35 UTCJul 24, 19:10 UTC2h 35m
2026-07-24 ASA481 SEA → BZE Jul 24, 04:10 UTCJul 24, 05:45 UTC1h 35m
2026-07-24 ASA319 BOS → SFO Jul 24, 01:05 UTCJul 24, 02:55 UTC1h 50m
2026-07-23 ASA555 MSP → SEA Jul 23, 20:15 UTCJul 23, 23:40 UTC3h 25m
2026-07-23 ASA555 MSP → SEA Jul 23, 16:25 UTCJul 23, 19:05 UTC2h 40m
2026-07-23 ASA387 MSP → SEA Jul 23, 11:10 UTCJul 23, 14:25 UTC3h 15m
2026-07-23 ASA387 MSP → SEA Jul 23, 11:08 UTCJul 23, 14:16 UTC3h 8m
2026-07-23 ASA386 SEA → MSP Jul 23, 02:30 UTCJul 23, 05:10 UTC2h 40m
2026-07-22 ASA425 SFO → BOS Jul 22, 21:50 UTCJul 23, 00:15 UTC2h 25m
2026-07-22 ASA747 - Jul 22, 17:40 UTCJul 22, 20:10 UTC2h 30m
2026-07-22 ASA1572 - Jul 22, 14:25 UTCJul 22, 16:30 UTC2h 5m
2026-07-22 ASA605 SFO → LAS Jul 22, 01:15 UTCJul 22, 03:25 UTC2h 10m
2026-07-21 ASA674 SEA → YYZ Jul 21, 21:45 UTCJul 22, 00:15 UTC2h 30m
2026-07-21 ASA716 SFO → SAN Jul 21, 17:50 UTCJul 21, 20:10 UTC2h 20m
2026-07-21 ASA1410 SFO → PDX Jul 21, 14:45 UTCJul 21, 16:00 UTC1h 15m
2026-07-21 ASA1410 SFO → PDX Jul 21, 14:44 UTCJul 21, 16:00 UTC1h 16m
2026-07-21 ASA291 MCI → SEA Jul 21, 05:46 UTCJul 21, 07:02 UTC1h 16m
2026-07-21 ASA291 MCI → SEA Jul 21, 06:00 UTCJul 21, 07:05 UTC1h 5m
2026-07-21 ASA780 SEA → ABQ Jul 21, 00:55 UTCJul 21, 03:20 UTC2h 25m
2026-07-20 ASA549 ZIH → SFO Jul 20, 20:00 UTCJul 20, 23:20 UTC3h 20m
2026-07-20 ASA348 ATL → SEA Jul 20, 13:15 UTCJul 20, 17:50 UTC4h 35m
2026-07-20 ASA464 FAI → ANC Jul 20, 06:55 UTCJul 20, 11:00 UTC4h 5m
2026-07-19 ASA234 FAI → SEA Jul 19, 23:05 UTCJul 20, 04:20 UTC5h 15m
2026-07-19 ASA220 - Jul 19, 15:45 UTCJul 19, 21:20 UTC5h 35m
2026-07-19 ASA1617 DEN → SAN Jul 19, 12:10 UTCJul 19, 14:00 UTC1h 50m
2026-07-19 ASA1619 SAN → DEN Jul 19, 03:05 UTCJul 19, 05:00 UTC1h 55m
2026-07-19 ASA266 SJC → PDX Jul 19, 00:55 UTCJul 19, 01:40 UTC45m
2026-07-18 ASA266 SJC → PDX Jul 18, 20:45 UTCJul 18, 20:55 UTC10m
2026-07-18 ASA693 - Jul 18, 19:25 UTCJul 18, 19:30 UTC5m
2026-07-18 ASA693 - Jul 18, 14:35 UTCJul 18, 15:15 UTC40m
2026-07-18 ASA634 LAS → SFO Jul 18, 01:34 UTCJul 18, 02:40 UTC1h 5m
2026-07-17 ASA778 PDX → LAS Jul 17, 22:05 UTCJul 18, 00:04 UTC2h 0m
2026-07-17 ASA1355 LAX → PDX Jul 17, 19:05 UTCJul 17, 20:50 UTC1h 45m
2026-07-17 ASA717 - Jul 17, 15:10 UTCJul 17, 17:30 UTC2h 20m
2026-07-16 ASA469 BNA → SEA Jul 16, 23:49 UTCJul 17, 04:20 UTC4h 30m
2026-07-16 ASA1376 PDX → BNA Jul 16, 17:54 UTCJul 16, 21:55 UTC4h 0m
2026-07-16 ASA1376 PDX → BNA Jul 16, 17:50 UTCJul 16, 21:48 UTC3h 58m
2026-07-16 ASA311 BOS → PDX Jul 16, 10:28 UTCJul 16, 16:12 UTC5h 44m
2026-07-16 ASA311 - Jul 16, 10:29 UTCJul 16, 14:25 UTC3h 55m
2026-07-16 ASA460 SEA → BOS Jul 16, 00:25 UTCJul 16, 05:00 UTC4h 35m

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 N516AS page for operator, model, and routing details .

Mode-S A677CA frequently asked

What is Mode-S code A677CA?
A677CA is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N516AS.
Where is Mode-S A677CA registered?
Mode-S code A677CA 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 A677CA broadcasting right now?
Yes. Mode-S A677CA is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A677CA, octal 51473712, decimal 10,909,642.
What flights does A677CA operate?
Mode-S A677CA has broadcast 20 distinct callsigns, including ASA9, ASA67, ASA4, ASA1565, ASA697.