sensors Mode-S transponder

A7DDE1

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N606DN · AIRBUS A-321neo · operated by DELTA AIR LINES INC

Hex
A7DDE1
Octal
51756741
Decimal
11,001,313
Country
US
Tail
N606DN
Type
A21N
Broadcasting now · callsign DAL884 · 35,000 ft
Flights observed
7
Distinct callsigns
4
Country
US
Last broadcast
23h ago

Current position

A7DDE1 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A7DDE1 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
DAL1024 Delta Air Lines 3 2026-04-13
DAL457 - 2 2026-04-13
DAL336 - 1 2026-04-13
DAL2019 - 1 2026-04-12

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 DAL1024 ATL → CHA Apr 13, 22:15 UTCApr 13, 23:45 UTC1h 30m
2026-04-13 DAL1024 ATL → CHA Apr 13, 19:50 UTCApr 13, 20:20 UTC30m
2026-04-13 DAL1024 ATL → CHA Apr 13, 18:05 UTCApr 13, 20:10 UTC2h 5m
2026-04-13 DAL336 DEN → JFK Apr 13, 12:45 UTCApr 13, 15:57 UTC3h 12m
2026-04-13 DAL457 - Apr 13, 00:20 UTCApr 13, 01:40 UTC1h 20m
2026-04-12 DAL457 - Apr 12, 23:55 UTCApr 13, 01:40 UTC1h 45m
2026-04-12 DAL2019 - Apr 12, 17:30 UTCApr 12, 19:40 UTC2h 10m

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 N606DN page for operator, model, and routing details .

Mode-S A7DDE1 frequently asked

What is Mode-S code A7DDE1?
A7DDE1 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N606DN.
Where is Mode-S A7DDE1 registered?
Mode-S code A7DDE1 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 A7DDE1 broadcasting right now?
Yes. Mode-S A7DDE1 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A7DDE1, octal 51756741, decimal 11,001,313.
What flights does A7DDE1 operate?
Mode-S A7DDE1 has broadcast 4 distinct callsigns, including DAL1024, DAL457, DAL336, DAL2019.