sensors Mode-S transponder

A9D63B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N733AL · BOEING 737 MAX 9 · operated by ALASKA AIRLINES INC

Hex
A9D63B
Octal
52353073
Decimal
11,130,427
Country
US
Tail
N733AL
Type
B39M
No current signal · last broadcast 1d ago
Flights observed
6
Distinct callsigns
5
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A9D63B.

Country allocation

The ICAO 24-bit address A9D63B 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 5 distinct

Callsign Airline Flights Last seen
ASA444 Alaska Airlines 2 2026-04-13
ASA91 - 1 2026-04-13
ASA81 Alaska Airlines 1 2026-04-13
ASA1430 - 1 2026-04-13
ASA1335 Alaska Airlines 1 2026-04-12

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 ASA444 SEA → PHL Apr 13, 19:50 UTCApr 13, 21:10 UTC1h 20m
2026-04-13 ASA444 SEA → PHL Apr 13, 18:40 UTCApr 13, 21:29 UTC2h 49m
2026-04-13 ASA1430 - Apr 13, 14:21 UTCApr 13, 16:54 UTC2h 33m
2026-04-13 ASA91 - Apr 13, 11:15 UTCApr 13, 12:00 UTC45m
2026-04-13 ASA81 ANC → ORD Apr 13, 00:03 UTCApr 13, 05:26 UTC5h 23m
2026-04-12 ASA1335 BZE → LAX Apr 12, 17:35 UTCApr 12, 20:15 UTC2h 40m

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 N733AL page for operator, model, and routing details .

Mode-S A9D63B frequently asked

What is Mode-S code A9D63B?
A9D63B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N733AL.
Where is Mode-S A9D63B registered?
Mode-S code A9D63B 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 A9D63B broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A9D63B, octal 52353073, decimal 11,130,427.
What flights does A9D63B operate?
Mode-S A9D63B has broadcast 5 distinct callsigns, including ASA444, ASA91, ASA81, ASA1430, ASA1335.