sensors Mode-S transponder

A9A397

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N720AL · BOEING 737 MAX 9 · operated by ALASKA AIRLINES INC

Hex
A9A397
Octal
52321627
Decimal
11,117,463
Country
US
Tail
N720AL
Type
B39M
No current signal · last broadcast 23h ago
Flights observed
10
Distinct callsigns
7
Country
US
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S A9A397.

Country allocation

The ICAO 24-bit address A9A397 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 7 distinct

Callsign Airline Flights Last seen
ASA152 - 3 2026-04-13
ASA104 - 2 2026-04-13
ASA521 Alaska Airlines 1 2026-04-13
ASA462 - 1 2026-04-12
ASA131 - 1 2026-04-13
ASA118 - 1 2026-04-13
ASA113 - 1 2026-04-13

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-13 ASA521 AUS → SEA Apr 13, 23:15 UTCApr 13, 23:45 UTC30m
2026-04-13 ASA104 - Apr 13, 19:50 UTCApr 13, 21:25 UTC1h 35m
2026-04-13 ASA104 - Apr 13, 18:43 UTCApr 13, 21:42 UTC2h 59m
2026-04-13 ASA113 FAI → ANC Apr 13, 13:15 UTCApr 13, 13:55 UTC40m
2026-04-13 ASA118 ANC → FAI Apr 13, 07:19 UTCApr 13, 07:50 UTC31m
2026-04-13 ASA152 - Apr 13, 04:20 UTCApr 13, 04:35 UTC15m
2026-04-13 ASA152 - Apr 13, 03:55 UTCApr 13, 04:35 UTC40m
2026-04-13 ASA152 - Apr 13, 03:53 UTCApr 13, 04:39 UTC46m
2026-04-13 ASA131 ANC → FAI Apr 13, 02:15 UTCApr 13, 02:55 UTC40m
2026-04-12 ASA462 - Apr 12, 17:45 UTCApr 12, 18:50 UTC1h 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 N720AL page for operator, model, and routing details .

Mode-S A9A397 frequently asked

What is Mode-S code A9A397?
A9A397 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N720AL.
Where is Mode-S A9A397 registered?
Mode-S code A9A397 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 A9A397 broadcasting right now?
No active broadcast right now. Last signal was 23h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A9A397, octal 52321627, decimal 11,117,463.
What flights does A9A397 operate?
Mode-S A9A397 has broadcast 7 distinct callsigns, including ASA152, ASA104, ASA521, ASA462, ASA131.