sensors Mode-S transponder

A445AD

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N37449 · operated by UNITED AIRLINES INC

Hex
A445AD
Octal
51042655
Decimal
10,765,741
Country
US
Tail
N37449
No current signal · last broadcast 16h ago
Flights observed
12
Distinct callsigns
7
Country
US
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S A445AD.

Country allocation

The ICAO 24-bit address A445AD 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 7 distinct

Callsign Airline Flights Last seen
UAL744 - 3 2026-04-13
UAL2095 - 3 2026-04-13
UAL1798 United Airlines 2 2026-04-13
UAL469 - 1 2026-04-12
UAL1609 - 1 2026-04-14
UAL1591 United Airlines 1 2026-04-13
UAL1076 United Airlines 1 2026-04-13

Recent flights last 12

DateFlightRouteTakeoffLandingDuration
2026-04-14 UAL1609 - Apr 14, 05:15 UTCApr 14, 06:50 UTC1h 35m
2026-04-13 UAL1076 DEN → SFO Apr 13, 23:40 UTCApr 13, 23:45 UTC5m
2026-04-13 UAL1798 IAH → PHX Apr 13, 19:50 UTCApr 13, 20:50 UTC1h 0m
2026-04-13 UAL1798 IAH → PHX Apr 13, 18:30 UTCApr 13, 20:10 UTC1h 40m
2026-04-13 UAL744 - Apr 13, 16:15 UTCApr 13, 16:35 UTC20m
2026-04-13 UAL744 - Apr 13, 15:50 UTCApr 13, 16:35 UTC45m
2026-04-13 UAL744 - Apr 13, 14:03 UTCApr 13, 17:01 UTC2h 58m
2026-04-13 UAL2095 - Apr 13, 04:20 UTCApr 13, 07:15 UTC2h 55m
2026-04-13 UAL2095 - Apr 13, 04:05 UTCApr 13, 07:15 UTC3h 10m
2026-04-13 UAL2095 - Apr 13, 03:20 UTCApr 13, 06:35 UTC3h 15m
2026-04-13 UAL1591 DEN → EWR Apr 13, 01:00 UTCApr 13, 01:40 UTC40m
2026-04-12 UAL469 - Apr 12, 17:15 UTCApr 12, 18:15 UTC1h 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 N37449 page for operator, model, and routing details .

Mode-S A445AD frequently asked

What is Mode-S code A445AD?
A445AD is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N37449.
Where is Mode-S A445AD registered?
Mode-S code A445AD 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 A445AD broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A445AD, octal 51042655, decimal 10,765,741.
What flights does A445AD operate?
Mode-S A445AD has broadcast 7 distinct callsigns, including UAL744, UAL2095, UAL1798, UAL469, UAL1609.