sensors Mode-S transponder

A05DDC

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N12225 · BOEING 737-800 · operated by UNITED AIRLINES INC

Hex
A05DDC
Octal
50056734
Decimal
10,509,788
Country
US
Tail
N12225
Type
B738
No current signal · last broadcast 1d ago
Flights observed
10
Distinct callsigns
6
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A05DDC.

Country allocation

The ICAO 24-bit address A05DDC 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 6 distinct

Callsign Airline Flights Last seen
UAL1823 - 3 2026-04-13
UAL497 United Airlines 2 2026-04-13
UAL1405 United Airlines 2 2026-04-13
UAL401 United Airlines 1 2026-04-13
UAL1737 - 1 2026-04-12
UAL1408 - 1 2026-04-13

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-13 UAL1405 BZE → IAH Apr 13, 20:35 UTCApr 13, 21:00 UTC25m
2026-04-13 UAL1405 BZE → IAH Apr 13, 19:05 UTCApr 13, 19:30 UTC25m
2026-04-13 UAL1408 - Apr 13, 15:05 UTCApr 13, 15:25 UTC20m
2026-04-13 UAL1823 - Apr 13, 12:30 UTCApr 13, 12:45 UTC15m
2026-04-13 UAL1823 - Apr 13, 11:55 UTCApr 13, 12:45 UTC50m
2026-04-13 UAL1823 - Apr 13, 11:25 UTCApr 13, 12:15 UTC50m
2026-04-13 UAL497 CVG → DEN Apr 13, 04:20 UTCApr 13, 05:00 UTC40m
2026-04-13 UAL497 CVG → DEN Apr 13, 03:55 UTCApr 13, 04:15 UTC20m
2026-04-13 UAL401 LIR → IAH Apr 13, 00:30 UTCApr 13, 01:05 UTC35m
2026-04-12 UAL1737 - Apr 12, 17:12 UTCApr 12, 20:38 UTC3h 26m

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 N12225 page for operator, model, and routing details .

Mode-S A05DDC frequently asked

What is Mode-S code A05DDC?
A05DDC is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N12225.
Where is Mode-S A05DDC registered?
Mode-S code A05DDC 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 A05DDC 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 A05DDC, octal 50056734, decimal 10,509,788.
What flights does A05DDC operate?
Mode-S A05DDC has broadcast 6 distinct callsigns, including UAL1823, UAL497, UAL1405, UAL401, UAL1737.