sensors Mode-S transponder

A64CDB

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N505DN · AIRBUS A-350-900 · operated by DELTA AIR LINES INC

Hex
A64CDB
Octal
51446333
Decimal
10,898,651
Country
US
Tail
N505DN
Type
A359
No current signal · last broadcast 13h ago
Flights observed
8
Distinct callsigns
3
Country
US
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S A64CDB.

Country allocation

The ICAO 24-bit address A64CDB 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
DAL69 Delta Air Lines 3 2026-04-14
DAL389 Delta Air Lines 3 2026-04-13
DAL280 - 2 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-14 DAL69 SEA → TPE Apr 14, 09:10 UTCApr 14, 09:40 UTC30m
2026-04-14 DAL69 SEA → TPE Apr 14, 08:35 UTCApr 14, 09:05 UTC30m
2026-04-13 DAL69 SEA → TPE Apr 13, 23:25 UTCApr 13, 23:40 UTC15m
2026-04-13 DAL280 - Apr 13, 16:45 UTCApr 13, 19:30 UTC2h 45m
2026-04-13 DAL280 - Apr 13, 10:45 UTCApr 13, 12:00 UTC1h 15m
2026-04-13 DAL389 JFK → DEN Apr 13, 04:20 UTCApr 13, 05:40 UTC1h 20m
2026-04-13 DAL389 JFK → DEN Apr 13, 03:55 UTCApr 13, 04:15 UTC20m
2026-04-12 DAL389 JFK → DEN Apr 12, 17:15 UTCApr 12, 18:05 UTC50m

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 N505DN page for operator, model, and routing details .

Mode-S A64CDB frequently asked

What is Mode-S code A64CDB?
A64CDB is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N505DN.
Where is Mode-S A64CDB registered?
Mode-S code A64CDB 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 A64CDB 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 A64CDB, octal 51446333, decimal 10,898,651.
What flights does A64CDB operate?
Mode-S A64CDB has broadcast 3 distinct callsigns, including DAL69, DAL389, DAL280.