sensors Mode-S transponder

AD077B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N939DZ · operated by DELTA AIR LINES INC

Hex
AD077B
Octal
53203573
Decimal
11,339,643
Country
US
Tail
N939DZ
Type
B739
No current signal · last broadcast 1d ago
Flights observed
8
Distinct callsigns
5
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AD077B.

Country allocation

The ICAO 24-bit address AD077B 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
DAL3163 - 3 2026-04-13
DAL2052 Delta Air Lines 2 2026-04-13
DAL3244 - 1 2026-04-13
DAL3109 Delta Air Lines 1 2026-04-12
DAL1192 - 1 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-13 DAL3163 - Apr 13, 21:30 UTCApr 13, 22:00 UTC30m
2026-04-13 DAL3163 - Apr 13, 19:50 UTCApr 13, 20:00 UTC10m
2026-04-13 DAL3163 - Apr 13, 19:39 UTCApr 13, 20:08 UTC29m
2026-04-13 DAL2052 SLC → STL Apr 13, 17:05 UTCApr 13, 18:00 UTC55m
2026-04-13 DAL2052 SLC → STL Apr 13, 14:37 UTCApr 13, 15:32 UTC55m
2026-04-13 DAL1192 - Apr 13, 10:30 UTCApr 13, 11:29 UTC59m
2026-04-13 DAL3244 - Apr 13, 01:05 UTCApr 13, 02:10 UTC1h 5m
2026-04-12 DAL3109 ATL → SRQ Apr 12, 19:45 UTCApr 12, 20:50 UTC1h 5m

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 N939DZ page for operator, model, and routing details .

Mode-S AD077B frequently asked

What is Mode-S code AD077B?
AD077B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N939DZ.
Where is Mode-S AD077B registered?
Mode-S code AD077B 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 AD077B 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 AD077B, octal 53203573, decimal 11,339,643.
What flights does AD077B operate?
Mode-S AD077B has broadcast 5 distinct callsigns, including DAL3163, DAL2052, DAL3244, DAL3109, DAL1192.