sensors Mode-S transponder

AB839D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N841AN · BOEING 787-9 Dreamliner · operated by AMERICAN AIRLINES INC

Hex
AB839D
Octal
52701635
Decimal
11,240,349
Country
US
Tail
N841AN
Type
B789
Broadcasting now · callsign AAL293 · 36,000 ft
Flights observed
8
Distinct callsigns
3
Country
US
Last broadcast
12h ago

Current position

AB839D is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AB839D 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 3 distinct

Callsign Airline Flights Last seen
AAL168 American Airlines 4 2026-04-13
AAL292 American Airlines 2 2026-04-14
AAL27 American Airlines 2 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-14 AAL292 JFK → DEL Apr 14, 09:10 UTCApr 14, 10:45 UTC1h 35m
2026-04-14 AAL292 JFK → DEL Apr 14, 07:00 UTCApr 14, 07:10 UTC10m
2026-04-13 AAL168 PDX → CLT Apr 13, 19:50 UTCApr 13, 21:30 UTC1h 40m
2026-04-13 AAL168 PDX → CLT Apr 13, 16:15 UTCApr 13, 20:10 UTC3h 55m
2026-04-13 AAL168 PDX → CLT Apr 13, 16:10 UTCApr 13, 19:45 UTC3h 35m
2026-04-13 AAL168 PDX → CLT Apr 13, 09:25 UTCApr 13, 10:05 UTC40m
2026-04-13 AAL27 LAX → HND Apr 13, 05:35 UTCApr 13, 06:25 UTC50m
2026-04-12 AAL27 LAX → HND Apr 12, 19:15 UTCApr 13, 06:24 UTC11h 9m

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 N841AN page for operator, model, and routing details .

Mode-S AB839D frequently asked

What is Mode-S code AB839D?
AB839D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N841AN.
Where is Mode-S AB839D registered?
Mode-S code AB839D 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 AB839D broadcasting right now?
Yes. Mode-S AB839D is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AB839D, octal 52701635, decimal 11,240,349.
What flights does AB839D operate?
Mode-S AB839D has broadcast 3 distinct callsigns, including AAL168, AAL292, AAL27.