sensors Mode-S transponder

A2CB33

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N27965 · BOEING 787-9 Dreamliner · operated by UNITED AIRLINES INC

Hex
A2CB33
Octal
50545463
Decimal
10,668,851
Country
US
Tail
N27965
Type
B789
Photo of N27965
No current signal · last broadcast 1d ago
Flights observed
5
Distinct callsigns
2
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A2CB33.

Country allocation

The ICAO 24-bit address A2CB33 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
UAL2679 United Airlines 4 2026-04-13
UAL78 United Airlines 1 2026-04-12

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-04-13 UAL2679 DEN → ORD Apr 13, 19:50 UTCApr 13, 20:05 UTC15m
2026-04-13 UAL2679 DEN → ORD Apr 13, 16:15 UTCApr 13, 20:05 UTC3h 50m
2026-04-13 UAL2679 DEN → ORD Apr 13, 15:50 UTCApr 13, 19:45 UTC3h 55m
2026-04-13 UAL2679 DEN → ORD Apr 13, 14:40 UTCApr 13, 16:15 UTC1h 35m
2026-04-12 UAL78 NRT → EWR Apr 12, 17:15 UTCApr 12, 20:15 UTC3h 0m

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 N27965 page for operator, model, and routing details .

Mode-S A2CB33 frequently asked

What is Mode-S code A2CB33?
A2CB33 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N27965.
Where is Mode-S A2CB33 registered?
Mode-S code A2CB33 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 A2CB33 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 A2CB33, octal 50545463, decimal 10,668,851.
What flights does A2CB33 operate?
Mode-S A2CB33 has broadcast 2 distinct callsigns, including UAL2679, UAL78.