sensors Mode-S transponder

A449A3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N37562 · BOEING 737 MAX 9 · operated by UNITED AIRLINES INC

Hex
A449A3
Octal
51044643
Decimal
10,766,755
Country
US
Tail
N37562
Type
B39M
No current signal · last broadcast 1d ago
Flights observed
9
Distinct callsigns
6
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A449A3.

Country allocation

The ICAO 24-bit address A449A3 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
UAL1864 United Airlines 3 2026-04-13
UAL259 - 2 2026-04-13
UAL370 - 1 2026-04-13
UAL2120 United Airlines 1 2026-04-12
UAL1592 - 1 2026-04-12
UAL1386 United Airlines 1 2026-04-13

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-04-13 UAL1386 LAS → EWR Apr 13, 23:15 UTCApr 13, 23:45 UTC30m
2026-04-13 UAL1864 DEN → IAH Apr 13, 19:50 UTCApr 13, 21:20 UTC1h 30m
2026-04-13 UAL1864 DEN → IAH Apr 13, 16:15 UTCApr 13, 20:10 UTC3h 55m
2026-04-13 UAL1864 DEN → IAH Apr 13, 16:05 UTCApr 13, 16:15 UTC10m
2026-04-13 UAL370 - Apr 13, 12:20 UTCApr 13, 14:25 UTC2h 5m
2026-04-13 UAL259 DEN → MCO Apr 13, 00:30 UTCApr 13, 03:35 UTC3h 5m
2026-04-13 UAL259 DEN → MCO Apr 13, 00:18 UTCApr 13, 03:22 UTC3h 4m
2026-04-12 UAL2120 MFE → IAH Apr 12, 19:08 UTCApr 12, 22:57 UTC3h 49m
2026-04-12 UAL1592 - Apr 12, 17:15 UTCApr 12, 17:40 UTC25m

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 N37562 page for operator, model, and routing details .

Mode-S A449A3 frequently asked

What is Mode-S code A449A3?
A449A3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N37562.
Where is Mode-S A449A3 registered?
Mode-S code A449A3 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 A449A3 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 A449A3, octal 51044643, decimal 10,766,755.
What flights does A449A3 operate?
Mode-S A449A3 has broadcast 6 distinct callsigns, including UAL1864, UAL259, UAL370, UAL2120, UAL1592.