sensors Mode-S transponder

A6EDA1

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N54552 · AIRBUS A-321neo · operated by UNITED AIRLINES INC

Hex
A6EDA1
Octal
51566641
Decimal
10,939,809
Country
US
Tail
N54552
Type
A21N
No current signal · last broadcast 16h ago
Flights observed
6
Distinct callsigns
5
Country
US
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S A6EDA1.

Country allocation

The ICAO 24-bit address A6EDA1 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 5 distinct

Callsign Airline Flights Last seen
UAL1010 United Airlines 2 2026-04-13
UAL3779 United Airlines 1 2026-04-13
UAL3750 United Airlines 1 2026-04-12
UAL2643 United Airlines 1 2026-04-13
UAL249 - 1 2026-04-14

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-14 UAL249 - Apr 14, 05:15 UTCApr 14, 07:10 UTC1h 55m
2026-04-13 UAL1010 OMA → SFO Apr 13, 22:30 UTCApr 13, 23:40 UTC1h 10m
2026-04-13 UAL1010 OMA → SFO Apr 13, 16:20 UTCApr 13, 19:20 UTC3h 0m
2026-04-13 UAL2643 DEN → BOS Apr 13, 12:20 UTCApr 13, 14:15 UTC1h 55m
2026-04-13 UAL3779 PIT → DEN Apr 13, 01:15 UTCApr 13, 03:50 UTC2h 35m
2026-04-12 UAL3750 CLE → IAH Apr 12, 18:35 UTCApr 12, 20:15 UTC1h 40m

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 N54552 page for operator, model, and routing details .

Mode-S A6EDA1 frequently asked

What is Mode-S code A6EDA1?
A6EDA1 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N54552.
Where is Mode-S A6EDA1 registered?
Mode-S code A6EDA1 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 A6EDA1 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 A6EDA1, octal 51566641, decimal 10,939,809.
What flights does A6EDA1 operate?
Mode-S A6EDA1 has broadcast 5 distinct callsigns, including UAL1010, UAL3779, UAL3750, UAL2643, UAL249.