sensors Mode-S transponder

A1C0EC

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N21197 · EMBRAER ERJ-145XR · operated by UNITED AIRLINES INC

Hex
A1C0EC
Octal
50340354
Decimal
10,600,684
Country
US
Tail
N21197
Type
E45X
Broadcasting now · callsign UCA4923 · 575 ft
Flights observed
17
Distinct callsigns
8
Country
US
Last broadcast
1d ago

Current position

A1C0EC is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A1C0EC 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 8 distinct

Callsign Airline Flights Last seen
UCA4917 - 3 2026-04-13
UCA4852 - 3 2026-04-13
UCA4242 - 3 2026-04-13
UCA4343 - 2 2026-04-13
UCA4303 - 2 2026-04-13
UCA4297 - 2 2026-04-13
UCA4285 - 1 2026-04-13
UCA4245 - 1 2026-04-12

Recent flights last 17

DateFlightRouteTakeoffLandingDuration
2026-04-13 UCA4285 - Apr 13, 21:25 UTCApr 13, 22:10 UTC45m
2026-04-13 UCA4242 - Apr 13, 19:50 UTCApr 13, 20:15 UTC25m
2026-04-13 UCA4242 - Apr 13, 19:39 UTCApr 13, 20:26 UTC47m
2026-04-13 UCA4242 - Apr 13, 19:39 UTCApr 13, 20:15 UTC36m
2026-04-13 UCA4297 - Apr 13, 17:28 UTCApr 13, 18:32 UTC1h 4m
2026-04-13 UCA4297 - Apr 13, 17:28 UTCApr 13, 18:15 UTC47m
2026-04-13 UCA4917 - Apr 13, 15:50 UTCApr 13, 16:05 UTC15m
2026-04-13 UCA4917 - Apr 13, 15:16 UTCApr 13, 16:23 UTC1h 7m
2026-04-13 UCA4917 - Apr 13, 15:16 UTCApr 13, 16:01 UTC45m
2026-04-13 UCA4852 - Apr 13, 12:20 UTCApr 13, 13:05 UTC45m
2026-04-13 UCA4852 - Apr 13, 11:55 UTCApr 13, 13:05 UTC1h 10m
2026-04-13 UCA4852 - Apr 13, 11:30 UTCApr 13, 12:15 UTC45m
2026-04-13 UCA4343 - Apr 13, 04:20 UTCApr 13, 05:00 UTC40m
2026-04-13 UCA4343 - Apr 13, 03:45 UTCApr 13, 04:15 UTC30m
2026-04-13 UCA4303 - Apr 13, 00:20 UTCApr 13, 01:25 UTC1h 5m
2026-04-13 UCA4303 - Apr 13, 00:02 UTCApr 13, 01:18 UTC1h 16m
2026-04-12 UCA4245 - Apr 12, 17:15 UTCApr 12, 18:10 UTC55m

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 N21197 page for operator, model, and routing details .

Mode-S A1C0EC frequently asked

What is Mode-S code A1C0EC?
A1C0EC is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N21197.
Where is Mode-S A1C0EC registered?
Mode-S code A1C0EC 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 A1C0EC broadcasting right now?
Yes. Mode-S A1C0EC is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1C0EC, octal 50340354, decimal 10,600,684.
What flights does A1C0EC operate?
Mode-S A1C0EC has broadcast 8 distinct callsigns, including UCA4917, UCA4852, UCA4242, UCA4343, UCA4303.