sensors Mode-S transponder

AB8B56

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N843DN · BOEING 737-900 · operated by DELTA AIR LINES INC

Hex
AB8B56
Octal
52705526
Decimal
11,242,326
Country
US
Tail
N843DN
Type
B739
No current signal · last broadcast 1d ago
Flights observed
2
Distinct callsigns
2
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AB8B56.

Country allocation

The ICAO 24-bit address AB8B56 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 2 distinct

Callsign Airline Flights Last seen
DAL766 Delta Air Lines 1 2026-04-13
DAL2194 Delta Air Lines 1 2026-04-12

Recent flights last 2

DateFlightRouteTakeoffLandingDuration
2026-04-13 DAL766 SFO → DTW Apr 13, 20:54 UTCApr 14, 00:45 UTC3h 51m
2026-04-12 DAL2194 BDL → ATL Apr 12, 17:15 UTCApr 12, 17:40 UTC25m

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 N843DN page for operator, model, and routing details .

Mode-S AB8B56 frequently asked

What is Mode-S code AB8B56?
AB8B56 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N843DN.
Where is Mode-S AB8B56 registered?
Mode-S code AB8B56 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 AB8B56 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 AB8B56, octal 52705526, decimal 11,242,326.
What flights does AB8B56 operate?
Mode-S AB8B56 has broadcast 2 distinct callsigns, including DAL766, DAL2194.