sensors Mode-S transponder

A6EDC3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N54561 · operated by UNITED AIRLINES INC

Hex
A6EDC3
Octal
51566703
Decimal
10,939,843
Country
US
Tail
N54561
No current signal · last broadcast 1h ago
Flights observed
15
Distinct callsigns
9
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A6EDC3.

Country allocation

The ICAO 24-bit address A6EDC3 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 9 distinct

Callsign Airline Flights Last seen
UAL2832 - 3 2026-07-14
UAL498T - 2 2026-07-13
UAL459 - 2 2026-07-13
UAL3896 - 2 2026-07-04
UAL3873 - 2 2026-07-12
UAL4214 - 1 2026-07-02
UAL2601 - 1 2026-07-13
UAL2499 - 1 2026-07-14
UAL1409 - 1 2026-07-12

Recent flights last 15

DateFlightRouteTakeoffLandingDuration
2026-07-14 UAL2499 - Jul 14, 02:10 UTCJul 14, 05:40 UTC3h 30m
2026-07-14 UAL2832 - Jul 14, 00:15 UTCJul 14, 00:20 UTC5m
2026-07-13 UAL2832 RSW → ORD Jul 13, 21:25 UTCJul 14, 00:20 UTC2h 55m
2026-07-13 UAL2832 RSW → ORD Jul 13, 20:53 UTCJul 14, 00:00 UTC3h 7m
2026-07-13 UAL2601 DEN → RSW Jul 13, 15:50 UTCJul 13, 19:20 UTC3h 30m
2026-07-13 UAL459 PDX → DEN Jul 13, 12:10 UTCJul 13, 14:20 UTC2h 10m
2026-07-13 UAL459 PDX → DEN Jul 13, 12:11 UTCJul 13, 14:17 UTC2h 6m
2026-07-13 UAL498T DEN → PDX Jul 13, 02:05 UTCJul 13, 04:15 UTC2h 10m
2026-07-13 UAL498T DEN → PDX Jul 13, 01:50 UTCJul 13, 04:09 UTC2h 19m
2026-07-12 UAL1409 - Jul 12, 20:20 UTCJul 12, 22:25 UTC2h 5m
2026-07-12 UAL3873 - Jul 12, 16:15 UTCJul 12, 18:15 UTC2h 0m
2026-07-12 UAL3873 MLB → IAH Jul 12, 16:08 UTCJul 12, 18:13 UTC2h 5m
2026-07-04 UAL3896 TPA → MLB Jul 4, 15:30 UTCJul 4, 16:00 UTC30m
2026-07-04 UAL3896 TPA → MLB Jul 4, 15:28 UTCJul 4, 15:56 UTC28m
2026-07-02 UAL4214 BFM → TPA Jul 2, 17:40 UTCJul 2, 18:50 UTC1h 10m

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 N54561 page for operator, model, and routing details .

Mode-S A6EDC3 frequently asked

What is Mode-S code A6EDC3?
A6EDC3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N54561.
Where is Mode-S A6EDC3 registered?
Mode-S code A6EDC3 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 A6EDC3 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A6EDC3, octal 51566703, decimal 10,939,843.
What flights does A6EDC3 operate?
Mode-S A6EDC3 has broadcast 9 distinct callsigns, including UAL2832, UAL498T, UAL459, UAL3896, UAL3873.