sensors Mode-S transponder

A71612

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N556DT · operated by DELTA AIR LINES INC

Hex
A71612
Octal
51613022
Decimal
10,950,162
Country
US
Tail
N556DT
No current signal · last broadcast 1d ago
Flights observed
21
Distinct callsigns
4
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A71612.

Country allocation

The ICAO 24-bit address A71612 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
DAL898 Delta Air Lines 6 2026-05-27
DAL446 Delta Air Lines 6 2026-05-28
DAL528 Delta Air Lines 5 2026-05-27
DAL827 Delta Air Lines 4 2026-05-28

Recent flights last 21

DateFlightRouteTakeoffLandingDuration
2026-05-28 DAL446 BOS → LAX May 28, 19:20 UTCMay 28, 23:35 UTC4h 15m
2026-05-28 DAL446 BOS → LAX May 28, 19:18 UTCMay 28, 23:25 UTC4h 7m
2026-05-28 DAL827 DEN → CVG May 28, 13:25 UTCMay 28, 17:45 UTC4h 20m
2026-05-27 DAL528 ATL → LGA May 27, 18:25 UTCMay 27, 22:20 UTC3h 55m
2026-05-27 DAL898 JFK → ATL May 27, 12:15 UTCMay 27, 16:35 UTC4h 20m
2026-05-26 DAL446 BOS → LAX May 26, 19:25 UTCMay 26, 23:29 UTC4h 5m
2026-05-26 DAL827 DEN → CVG May 26, 13:24 UTCMay 26, 17:25 UTC4h 0m
2026-05-25 DAL446 BOS → LAX May 25, 19:15 UTCMay 25, 23:24 UTC4h 10m
2026-05-25 DAL446 BOS → LAX May 25, 19:12 UTCMay 25, 23:26 UTC4h 14m
2026-05-25 DAL827 DEN → CVG May 25, 13:20 UTCMay 25, 17:25 UTC4h 5m
2026-05-24 DAL528 ATL → LGA May 24, 18:20 UTCMay 24, 21:45 UTC3h 25m
2026-05-24 DAL898 JFK → ATL May 24, 12:20 UTCMay 24, 16:25 UTC4h 5m
2026-05-23 DAL446 BOS → LAX May 23, 19:15 UTCMay 23, 23:05 UTC3h 50m
2026-05-23 DAL827 DEN → CVG May 23, 13:30 UTCMay 23, 17:45 UTC4h 15m
2026-05-22 DAL528 ATL → LGA May 22, 18:25 UTCMay 22, 22:45 UTC4h 20m
2026-05-22 DAL898 JFK → ATL May 22, 12:40 UTCMay 22, 16:50 UTC4h 10m
2026-05-21 DAL528 ATL → LGA May 21, 18:35 UTCMay 21, 22:30 UTC3h 55m
2026-05-21 DAL898 JFK → ATL May 21, 12:25 UTCMay 21, 16:45 UTC4h 20m
2026-05-20 DAL528 ATL → LGA May 20, 18:30 UTCMay 20, 22:25 UTC3h 55m
2026-05-20 DAL898 JFK → ATL May 20, 12:36 UTCMay 20, 16:45 UTC4h 9m
2026-05-20 DAL898 JFK → ATL May 20, 12:40 UTCMay 20, 17:10 UTC4h 30m

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 N556DT page for operator, model, and routing details .

Mode-S A71612 frequently asked

What is Mode-S code A71612?
A71612 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N556DT.
Where is Mode-S A71612 registered?
Mode-S code A71612 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 A71612 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 A71612, octal 51613022, decimal 10,950,162.
What flights does A71612 operate?
Mode-S A71612 has broadcast 4 distinct callsigns, including DAL898, DAL446, DAL528, DAL827.