sensors Mode-S transponder

AB4B34

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N827DN · BOEING 737-900 · operated by DELTA AIR LINES INC

Hex
AB4B34
Octal
52645464
Decimal
11,225,908
Country
US
Tail
N827DN
Type
B739
No current signal · last broadcast 1d ago
Flights observed
6
Distinct callsigns
4
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AB4B34.

Country allocation

The ICAO 24-bit address AB4B34 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
DAL2775 Delta Air Lines 2 2026-04-13
DAL2428 Delta Air Lines 2 2026-04-13
DAL532 - 1 2026-04-12
DAL1428 - 1 2026-04-13

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 DAL2775 ATL → MSP Apr 13, 20:45 UTCApr 13, 23:00 UTC2h 15m
2026-04-13 DAL2775 ATL → MSP Apr 13, 16:50 UTCApr 13, 19:00 UTC2h 10m
2026-04-13 DAL2428 SEA → SAN Apr 13, 12:20 UTCApr 13, 14:25 UTC2h 5m
2026-04-13 DAL2428 SEA → SAN Apr 13, 11:55 UTCApr 13, 12:15 UTC20m
2026-04-13 DAL1428 - Apr 13, 00:35 UTCApr 13, 02:50 UTC2h 15m
2026-04-12 DAL532 - Apr 12, 19:03 UTCApr 12, 22:21 UTC3h 18m

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 N827DN page for operator, model, and routing details .

Mode-S AB4B34 frequently asked

What is Mode-S code AB4B34?
AB4B34 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N827DN.
Where is Mode-S AB4B34 registered?
Mode-S code AB4B34 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 AB4B34 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 AB4B34, octal 52645464, decimal 11,225,908.
What flights does AB4B34 operate?
Mode-S AB4B34 has broadcast 4 distinct callsigns, including DAL2775, DAL2428, DAL532, DAL1428.