sensors Mode-S transponder

AB6851

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N834MH · BOEING 767-400 · operated by DELTA AIR LINES INC

Hex
AB6851
Octal
52664121
Decimal
11,233,361
Country
US
Tail
N834MH
Type
B764
Photo of N834MH
Transponder active on ground
Flights observed
8
Distinct callsigns
2
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AB6851.

Country allocation

The ICAO 24-bit address AB6851 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 2 distinct

Callsign Airline Flights Last seen
DAL193 Delta Air Lines 5 2026-04-13
DAL192 Delta Air Lines 3 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-13 DAL193 VCE → ATL Apr 13, 16:20 UTCApr 13, 19:35 UTC3h 15m
2026-04-13 DAL193 VCE → ATL Apr 13, 16:10 UTCApr 13, 19:35 UTC3h 25m
2026-04-13 DAL193 VCE → ATL Apr 13, 11:55 UTCApr 13, 12:05 UTC10m
2026-04-13 DAL193 VCE → ATL Apr 13, 09:20 UTCApr 13, 12:05 UTC2h 45m
2026-04-13 DAL192 ATL → VCE Apr 13, 04:40 UTCApr 13, 07:10 UTC2h 30m
2026-04-13 DAL192 ATL → VCE Apr 13, 00:20 UTCApr 13, 01:25 UTC1h 5m
2026-04-12 DAL192 ATL → VCE Apr 12, 23:55 UTCApr 13, 01:25 UTC1h 30m
2026-04-12 DAL193 VCE → ATL Apr 12, 17:15 UTCApr 12, 19:55 UTC2h 40m

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 N834MH page for operator, model, and routing details .

Mode-S AB6851 frequently asked

What is Mode-S code AB6851?
AB6851 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N834MH.
Where is Mode-S AB6851 registered?
Mode-S code AB6851 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 AB6851 broadcasting right now?
Mode-S AB6851 is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AB6851, octal 52664121, decimal 11,233,361.
What flights does AB6851 operate?
Mode-S AB6851 has broadcast 2 distinct callsigns, including DAL193, DAL192.