sensors Mode-S transponder

A14AD4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N18223 · BOEING 737-800 · operated by UNITED AIRLINES INC

Hex
A14AD4
Octal
50245324
Decimal
10,570,452
Country
US
Tail
N18223
Type
B738
No current signal · last broadcast 1d ago
Flights observed
8
Distinct callsigns
7
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A14AD4.

Country allocation

The ICAO 24-bit address A14AD4 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
UAL1812 - 2 2026-04-13
UAL755 United Airlines 1 2026-04-13
UAL2615 - 1 2026-04-13
UAL2047 - 1 2026-04-13
UAL1960 - 1 2026-04-13
UAL1757 - 1 2026-04-13
UAL1095 United Airlines 1 2026-04-12

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-13 UAL2047 - Apr 13, 23:20 UTCApr 13, 23:40 UTC20m
2026-04-13 UAL1960 SFO → LAS Apr 13, 20:20 UTCApr 13, 21:35 UTC1h 15m
2026-04-13 UAL755 IAD → BOS Apr 13, 17:50 UTCApr 13, 18:40 UTC50m
2026-04-13 UAL1757 - Apr 13, 06:40 UTCApr 13, 07:10 UTC30m
2026-04-13 UAL2615 - Apr 13, 02:25 UTCApr 13, 03:57 UTC1h 32m
2026-04-13 UAL1812 - Apr 13, 00:20 UTCApr 13, 00:40 UTC20m
2026-04-12 UAL1812 - Apr 12, 23:55 UTCApr 13, 00:40 UTC45m
2026-04-12 UAL1095 MYR → EWR Apr 12, 18:25 UTCApr 12, 18:55 UTC30m

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 N18223 page for operator, model, and routing details .

Mode-S A14AD4 frequently asked

What is Mode-S code A14AD4?
A14AD4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N18223.
Where is Mode-S A14AD4 registered?
Mode-S code A14AD4 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 A14AD4 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 A14AD4, octal 50245324, decimal 10,570,452.
What flights does A14AD4 operate?
Mode-S A14AD4 has broadcast 7 distinct callsigns, including UAL1812, UAL755, UAL2615, UAL2047, UAL1960.