sensors Mode-S transponder

A29551

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N266AK · BOEING 737-900 · operated by ALASKA AIRLINES INC

Hex
A29551
Octal
50512521
Decimal
10,655,057
Country
US
Tail
N266AK
Type
B739
No current signal · last broadcast 4h ago
Flights observed
215
Distinct callsigns
20
Country
US
Last broadcast
4h ago

Last known position

Most recent position reported by Mode-S A29551.

Country allocation

The ICAO 24-bit address A29551 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
ASA508 Alaska Airlines 8 2026-05-10
ASA106 Alaska Airlines 5 2026-04-16
ASA443 Alaska Airlines 4 2026-04-18
ASA442 Alaska Airlines 4 2026-04-17
ASA274 Alaska Airlines 4 2026-05-26
ASA208 Alaska Airlines 4 2026-04-14
ASA799 - 3 2026-04-15
ASA691 Alaska Airlines 3 2026-04-15
ASA299 Alaska Airlines 3 2026-04-16
ASA1370 Alaska Airlines 3 2026-05-23
ASA1369 Alaska Airlines 3 2026-05-01
ASA95 Alaska Airlines 2 2026-05-24
ASA79 Alaska Airlines 2 2026-05-27
ASA787 Alaska Airlines 2 2026-05-07
ASA780 Alaska Airlines 2 2026-04-22
ASA754 Alaska Airlines 2 2026-04-15
ASA701 Alaska Airlines 2 2026-05-10
ASA69 Alaska Airlines 2 2026-05-25
ASA684 Alaska Airlines 2 2026-05-29
ASA682 Alaska Airlines 2 2026-05-16

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 ASA649 LAS → PDX May 30, 01:45 UTCMay 30, 03:45 UTC2h 0m
2026-05-29 ASA1386 PVR → SFO May 29, 22:55 UTCMay 30, 00:40 UTC1h 45m
2026-05-29 ASA684 SFO → LAS May 29, 18:15 UTCMay 29, 20:25 UTC2h 10m
2026-05-29 ASA684 SFO → LAS May 29, 14:35 UTCMay 29, 16:55 UTC2h 20m
2026-05-28 ASA337 DAL → SFO May 28, 22:50 UTCMay 29, 02:20 UTC3h 30m
2026-05-28 ASA338 SEA → SJC May 28, 17:50 UTCMay 28, 21:35 UTC3h 45m
2026-05-28 ASA541 AUS → PDX May 28, 12:30 UTCMay 28, 16:00 UTC3h 30m
2026-05-28 ASA461 ANC → FAI May 28, 01:25 UTCMay 28, 05:10 UTC3h 45m
2026-05-27 ASA230 SMF → SEA May 27, 20:20 UTCMay 27, 23:30 UTC3h 10m
2026-05-27 ASA79 SJC → PVR May 27, 15:35 UTCMay 27, 18:50 UTC3h 15m
2026-05-27 ASA79 SJC → PVR May 27, 15:49 UTCMay 27, 18:49 UTC3h 0m
2026-05-27 ASA611 LAX → SEA May 27, 04:39 UTCMay 27, 06:55 UTC2h 15m
2026-05-26 ASA744 SEA → PHX May 26, 23:39 UTCMay 27, 02:14 UTC2h 35m
2026-05-26 ASA580 PSP → SEA May 26, 20:24 UTCMay 26, 21:59 UTC1h 35m
2026-05-26 ASA364 BOS → SEA May 26, 12:45 UTCMay 26, 18:24 UTC5h 40m
2026-05-26 ASA274 SEA → EWR May 26, 06:25 UTCMay 26, 11:05 UTC4h 40m
2026-05-25 ASA379 BWI → SEA May 25, 23:49 UTCMay 26, 05:00 UTC5h 10m
2026-05-25 ASA379 BWI → SEA May 25, 17:40 UTCMay 25, 22:19 UTC4h 39m
2026-05-25 ASA433 IAD → SFO May 25, 13:30 UTCMay 25, 15:35 UTC2h 5m
2026-05-25 ASA433 IAD → SFO May 25, 13:33 UTCMay 25, 15:29 UTC1h 56m
2026-05-25 ASA69 SEA → KTN May 25, 04:30 UTCMay 25, 05:00 UTC30m
2026-05-25 ASA69 SEA → KTN May 25, 01:55 UTCMay 25, 03:15 UTC1h 20m
2026-05-24 ASA95 SEA → AUS May 24, 23:00 UTCMay 24, 23:46 UTC46m
2026-05-24 ASA95 SEA → AUS May 24, 18:50 UTCMay 24, 20:50 UTC2h 0m
2026-05-24 ASA92 ANC → SEA May 24, 15:15 UTCMay 24, 17:00 UTC1h 45m
2026-05-24 ASA91 ANC → FAI May 24, 04:25 UTCMay 24, 06:20 UTC1h 55m
2026-05-24 ASA401 DAL → SFO May 24, 00:05 UTCMay 24, 02:40 UTC2h 35m
2026-05-23 ASA417 PIT → SEA May 23, 20:30 UTCMay 23, 22:55 UTC2h 25m
2026-05-23 ASA463 TPA → SEA May 23, 14:10 UTCMay 23, 18:15 UTC4h 6m
2026-05-23 ASA1370 PVR → SFO May 23, 00:45 UTCMay 23, 04:15 UTC3h 29m
2026-05-22 ASA624 SEA → IND May 22, 22:05 UTCMay 22, 23:15 UTC1h 10m
2026-05-22 ASA681 DEN → SEA May 22, 19:15 UTCMay 22, 20:35 UTC1h 20m
2026-05-22 ASA640 LAX → SFO May 22, 11:55 UTCMay 22, 17:40 UTC5h 45m
2026-05-22 ASA639 PHX → SEA May 22, 05:05 UTCMay 22, 10:15 UTC5h 10m
2026-05-22 ASA552 LAX → SEA May 22, 01:05 UTCMay 22, 03:20 UTC2h 15m
2026-05-22 ASA552 LAX → SEA May 22, 01:04 UTCMay 22, 03:06 UTC2h 2m
2026-05-21 ASA778 SJC → SEA May 21, 21:45 UTCMay 21, 23:30 UTC1h 45m
2026-05-21 ASA1467 LAS → PDX May 21, 18:15 UTCMay 21, 20:10 UTC1h 55m
2026-05-21 ASA627 SLC → SEA May 21, 14:50 UTCMay 21, 16:35 UTC1h 45m
2026-05-20 ASA1421 SNA → SEA May 20, 23:15 UTCMay 21, 03:20 UTC4h 5m
2026-05-20 ASA438 SEA → IAH May 20, 18:00 UTCMay 20, 21:45 UTC3h 45m
2026-05-20 ASA605 SFO → LAS May 20, 13:40 UTCMay 20, 16:20 UTC2h 40m
2026-05-20 ASA604 LAS → LAX May 20, 02:20 UTCMay 20, 04:40 UTC2h 21m
2026-05-19 ASA1486 SEA → BUR May 19, 21:15 UTCMay 20, 00:00 UTC2h 45m
2026-05-19 ASA519 FLL → SEA May 19, 13:45 UTCMay 19, 19:25 UTC5h 40m
2026-05-19 ASA752 SEA → PSP May 19, 07:20 UTCMay 19, 12:00 UTC4h 40m
2026-05-19 ASA53 EWR → PDX May 19, 00:50 UTCMay 19, 06:20 UTC5h 30m
2026-05-18 ASA658 SEA → PHX May 18, 21:25 UTCMay 18, 23:15 UTC1h 50m
2026-05-18 ASA658 SEA → PHX May 18, 21:21 UTCMay 18, 23:12 UTC1h 51m
2026-05-18 ASA537 BOS → SEA May 18, 13:49 UTCMay 18, 19:11 UTC5h 22m

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 N266AK page for operator, model, and routing details .

Mode-S A29551 frequently asked

What is Mode-S code A29551?
A29551 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N266AK.
Where is Mode-S A29551 registered?
Mode-S code A29551 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 A29551 broadcasting right now?
No active broadcast right now. Last signal was 4h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A29551, octal 50512521, decimal 10,655,057.
What flights does A29551 operate?
Mode-S A29551 has broadcast 20 distinct callsigns, including ASA508, ASA106, ASA443, ASA442, ASA274.