sensors Mode-S transponder

A6F23D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N547DE · AIRBUS A-321neo · operated by DELTA AIR LINES INC

Hex
A6F23D
Octal
51571075
Decimal
10,940,989
Country
US
Tail
N547DE
Type
A21N
No current signal · last broadcast 13h ago
Flights observed
10
Distinct callsigns
5
Country
US
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S A6F23D.

Country allocation

The ICAO 24-bit address A6F23D 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
DAL546 - 3 2026-04-13
DAL373 Delta Air Lines 3 2026-04-14
DAL798 Delta Air Lines 2 2026-04-13
DAL806 Delta Air Lines 1 2026-04-13
DAL386 - 1 2026-04-12

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-14 DAL373 PDX → ATL Apr 14, 09:10 UTCApr 14, 09:25 UTC15m
2026-04-14 DAL373 PDX → ATL Apr 14, 07:10 UTCApr 14, 09:05 UTC1h 55m
2026-04-14 DAL373 PDX → ATL Apr 14, 05:15 UTCApr 14, 07:10 UTC1h 55m
2026-04-13 DAL806 JFK → SJU Apr 13, 21:35 UTCApr 13, 23:40 UTC2h 5m
2026-04-13 DAL546 - Apr 13, 16:15 UTCApr 13, 17:15 UTC1h 0m
2026-04-13 DAL546 - Apr 13, 15:50 UTCApr 13, 17:15 UTC1h 25m
2026-04-13 DAL546 - Apr 13, 13:10 UTCApr 13, 16:15 UTC3h 5m
2026-04-13 DAL798 CVG → SLC Apr 13, 00:20 UTCApr 13, 02:35 UTC2h 15m
2026-04-12 DAL798 CVG → SLC Apr 12, 23:55 UTCApr 13, 02:35 UTC2h 40m
2026-04-12 DAL386 - Apr 12, 17:15 UTCApr 12, 19:40 UTC2h 25m

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 N547DE page for operator, model, and routing details .

Mode-S A6F23D frequently asked

What is Mode-S code A6F23D?
A6F23D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N547DE.
Where is Mode-S A6F23D registered?
Mode-S code A6F23D 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 A6F23D broadcasting right now?
No active broadcast right now. Last signal was 13h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A6F23D, octal 51571075, decimal 10,940,989.
What flights does A6F23D operate?
Mode-S A6F23D has broadcast 5 distinct callsigns, including DAL546, DAL373, DAL798, DAL806, DAL386.