sensors Mode-S transponder

AC259B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N882DN · BOEING 737-900 · operated by UMB BANK NA TRUSTEE

Hex
AC259B
Octal
53022633
Decimal
11,281,819
Country
US
Tail
N882DN
Type
B739
Photo of N882DN
Broadcasting now · callsign DAL1144 · 39,000 ft
Flights observed
9
Distinct callsigns
4
Country
US
Last broadcast
1d ago

Current position

AC259B is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AC259B 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 4 distinct

Callsign Airline Flights Last seen
DAL565 - 3 2026-04-13
DAL1628 Delta Air Lines 3 2026-04-13
DAL413 - 2 2026-04-13
DAL1913 - 1 2026-04-12

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-04-13 DAL413 - Apr 13, 19:50 UTCApr 13, 21:35 UTC1h 45m
2026-04-13 DAL413 - Apr 13, 18:47 UTCApr 13, 21:38 UTC2h 51m
2026-04-13 DAL1628 ATL → SFO Apr 13, 16:15 UTCApr 13, 17:05 UTC50m
2026-04-13 DAL1628 ATL → SFO Apr 13, 15:50 UTCApr 13, 17:05 UTC1h 15m
2026-04-13 DAL1628 ATL → SFO Apr 13, 15:05 UTCApr 13, 16:15 UTC1h 10m
2026-04-13 DAL565 - Apr 13, 04:20 UTCApr 13, 05:00 UTC40m
2026-04-13 DAL565 - Apr 13, 03:55 UTCApr 13, 05:00 UTC1h 5m
2026-04-13 DAL565 - Apr 13, 00:31 UTCApr 13, 04:49 UTC4h 18m
2026-04-12 DAL1913 - Apr 12, 18:25 UTCApr 12, 18:35 UTC10m

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 N882DN page for operator, model, and routing details .

Mode-S AC259B frequently asked

What is Mode-S code AC259B?
AC259B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N882DN.
Where is Mode-S AC259B registered?
Mode-S code AC259B 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 AC259B broadcasting right now?
Yes. Mode-S AC259B is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC259B, octal 53022633, decimal 11,281,819.
What flights does AC259B operate?
Mode-S AC259B has broadcast 4 distinct callsigns, including DAL565, DAL1628, DAL413, DAL1913.