sensors Mode-S transponder

AB34F3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N821DX · BOEING 757-200 · operated by DELTA AIR LINES INC

Hex
AB34F3
Octal
52632363
Decimal
11,220,211
Country
US
Tail
N821DX
Type
B752
No current signal · last broadcast 1d ago
Flights observed
8
Distinct callsigns
4
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AB34F3.

Country allocation

The ICAO 24-bit address AB34F3 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
DAL569 Delta Air Lines 3 2026-04-13
DAL375 - 2 2026-04-13
DAL1214 - 2 2026-04-13
DAL428 Delta Air Lines 1 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-13 DAL1214 - Apr 13, 22:35 UTCApr 13, 23:40 UTC1h 5m
2026-04-13 DAL1214 - Apr 13, 20:00 UTCApr 13, 20:10 UTC10m
2026-04-13 DAL569 ATL → LGA Apr 13, 16:15 UTCApr 13, 18:05 UTC1h 50m
2026-04-13 DAL569 ATL → LGA Apr 13, 15:50 UTCApr 13, 18:05 UTC2h 15m
2026-04-13 DAL569 ATL → LGA Apr 13, 13:33 UTCApr 13, 17:31 UTC3h 58m
2026-04-13 DAL375 - Apr 13, 11:55 UTCApr 13, 12:10 UTC15m
2026-04-13 DAL375 - Apr 13, 11:15 UTCApr 13, 12:10 UTC55m
2026-04-13 DAL428 SJC → ATL Apr 13, 04:10 UTCApr 13, 04:25 UTC15m

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 N821DX page for operator, model, and routing details .

Mode-S AB34F3 frequently asked

What is Mode-S code AB34F3?
AB34F3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N821DX.
Where is Mode-S AB34F3 registered?
Mode-S code AB34F3 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 AB34F3 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 AB34F3, octal 52632363, decimal 11,220,211.
What flights does AB34F3 operate?
Mode-S AB34F3 has broadcast 4 distinct callsigns, including DAL569, DAL375, DAL1214, DAL428.